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a51b484af19b57f15279d3c0f1ce948c4ce9c786eda86d959008c905076e80d4 | import warnings
from io import StringIO
from django.template.base import Lexer, TokenType
from django.utils.regex_helper import _lazy_re_compile
from . import TranslatorCommentWarning, trim_whitespace
TRANSLATOR_COMMENT_MARK = 'Translators'
dot_re = _lazy_re_compile(r'\S')
def blankout(src, char):
"""
Change every non-whitespace character to the given char.
Used in the templatize function.
"""
return dot_re.sub(char, src)
context_re = _lazy_re_compile(r"""^\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?'))\s*""")
inline_re = _lazy_re_compile(
# Match the trans/translate 'some text' part.
r"""^\s*trans(?:late)?\s+((?:"[^"]*?")|(?:'[^']*?'))"""
# Match and ignore optional filters
r"""(?:\s*\|\s*[^\s:]+(?::(?:[^\s'":]+|(?:"[^"]*?")|(?:'[^']*?')))?)*"""
# Match the optional context part
r"""(\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?')))?\s*"""
)
block_re = _lazy_re_compile(r"""^\s*blocktrans(?:late)?(\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?')))?(?:\s+|$)""")
endblock_re = _lazy_re_compile(r"""^\s*endblocktrans(?:late)?$""")
plural_re = _lazy_re_compile(r"""^\s*plural$""")
constant_re = _lazy_re_compile(r"""_\(((?:".*?")|(?:'.*?'))\)""")
def templatize(src, origin=None):
"""
Turn a Django template into something that is understood by xgettext. It
does so by translating the Django translation tags into standard gettext
function invocations.
"""
out = StringIO('')
message_context = None
intrans = False
inplural = False
trimmed = False
singular = []
plural = []
incomment = False
comment = []
lineno_comment_map = {}
comment_lineno_cache = None
# Adding the u prefix allows gettext to recognize the string (#26093).
raw_prefix = 'u'
def join_tokens(tokens, trim=False):
message = ''.join(tokens)
if trim:
message = trim_whitespace(message)
return message
for t in Lexer(src).tokenize():
if incomment:
if t.token_type == TokenType.BLOCK and t.contents == 'endcomment':
content = ''.join(comment)
translators_comment_start = None
for lineno, line in enumerate(content.splitlines(True)):
if line.lstrip().startswith(TRANSLATOR_COMMENT_MARK):
translators_comment_start = lineno
for lineno, line in enumerate(content.splitlines(True)):
if translators_comment_start is not None and lineno >= translators_comment_start:
out.write(' # %s' % line)
else:
out.write(' #\n')
incomment = False
comment = []
else:
comment.append(t.contents)
elif intrans:
if t.token_type == TokenType.BLOCK:
endbmatch = endblock_re.match(t.contents)
pluralmatch = plural_re.match(t.contents)
if endbmatch:
if inplural:
if message_context:
out.write(' npgettext({p}{!r}, {p}{!r}, {p}{!r},count) '.format(
message_context,
join_tokens(singular, trimmed),
join_tokens(plural, trimmed),
p=raw_prefix,
))
else:
out.write(' ngettext({p}{!r}, {p}{!r}, count) '.format(
join_tokens(singular, trimmed),
join_tokens(plural, trimmed),
p=raw_prefix,
))
for part in singular:
out.write(blankout(part, 'S'))
for part in plural:
out.write(blankout(part, 'P'))
else:
if message_context:
out.write(' pgettext({p}{!r}, {p}{!r}) '.format(
message_context,
join_tokens(singular, trimmed),
p=raw_prefix,
))
else:
out.write(' gettext({p}{!r}) '.format(
join_tokens(singular, trimmed),
p=raw_prefix,
))
for part in singular:
out.write(blankout(part, 'S'))
message_context = None
intrans = False
inplural = False
singular = []
plural = []
elif pluralmatch:
inplural = True
else:
filemsg = ''
if origin:
filemsg = 'file %s, ' % origin
raise SyntaxError(
"Translation blocks must not include other block tags: "
"%s (%sline %d)" % (t.contents, filemsg, t.lineno)
)
elif t.token_type == TokenType.VAR:
if inplural:
plural.append('%%(%s)s' % t.contents)
else:
singular.append('%%(%s)s' % t.contents)
elif t.token_type == TokenType.TEXT:
contents = t.contents.replace('%', '%%')
if inplural:
plural.append(contents)
else:
singular.append(contents)
else:
# Handle comment tokens (`{# ... #}`) plus other constructs on
# the same line:
if comment_lineno_cache is not None:
cur_lineno = t.lineno + t.contents.count('\n')
if comment_lineno_cache == cur_lineno:
if t.token_type != TokenType.COMMENT:
for c in lineno_comment_map[comment_lineno_cache]:
filemsg = ''
if origin:
filemsg = 'file %s, ' % origin
warn_msg = (
"The translator-targeted comment '%s' "
"(%sline %d) was ignored, because it wasn't "
"the last item on the line."
) % (c, filemsg, comment_lineno_cache)
warnings.warn(warn_msg, TranslatorCommentWarning)
lineno_comment_map[comment_lineno_cache] = []
else:
out.write('# %s' % ' | '.join(lineno_comment_map[comment_lineno_cache]))
comment_lineno_cache = None
if t.token_type == TokenType.BLOCK:
imatch = inline_re.match(t.contents)
bmatch = block_re.match(t.contents)
cmatches = constant_re.findall(t.contents)
if imatch:
g = imatch[1]
if g[0] == '"':
g = g.strip('"')
elif g[0] == "'":
g = g.strip("'")
g = g.replace('%', '%%')
if imatch[2]:
# A context is provided
context_match = context_re.match(imatch[2])
message_context = context_match[1]
if message_context[0] == '"':
message_context = message_context.strip('"')
elif message_context[0] == "'":
message_context = message_context.strip("'")
out.write(' pgettext({p}{!r}, {p}{!r}) '.format(
message_context, g, p=raw_prefix
))
message_context = None
else:
out.write(' gettext({p}{!r}) '.format(g, p=raw_prefix))
elif bmatch:
for fmatch in constant_re.findall(t.contents):
out.write(' _(%s) ' % fmatch)
if bmatch[1]:
# A context is provided
context_match = context_re.match(bmatch[1])
message_context = context_match[1]
if message_context[0] == '"':
message_context = message_context.strip('"')
elif message_context[0] == "'":
message_context = message_context.strip("'")
intrans = True
inplural = False
trimmed = 'trimmed' in t.split_contents()
singular = []
plural = []
elif cmatches:
for cmatch in cmatches:
out.write(' _(%s) ' % cmatch)
elif t.contents == 'comment':
incomment = True
else:
out.write(blankout(t.contents, 'B'))
elif t.token_type == TokenType.VAR:
parts = t.contents.split('|')
cmatch = constant_re.match(parts[0])
if cmatch:
out.write(' _(%s) ' % cmatch[1])
for p in parts[1:]:
if p.find(':_(') >= 0:
out.write(' %s ' % p.split(':', 1)[1])
else:
out.write(blankout(p, 'F'))
elif t.token_type == TokenType.COMMENT:
if t.contents.lstrip().startswith(TRANSLATOR_COMMENT_MARK):
lineno_comment_map.setdefault(t.lineno, []).append(t.contents)
comment_lineno_cache = t.lineno
else:
out.write(blankout(t.contents, 'X'))
return out.getvalue()
|
901aa9fa17e226bcd9a4b16176fc7fcf4d1abbbd969b058724a557fd4641f4bb | from pathlib import Path
import jinja2
from django.conf import settings
from django.template import TemplateDoesNotExist, TemplateSyntaxError
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from .base import BaseEngine
class Jinja2(BaseEngine):
app_dirname = 'jinja2'
def __init__(self, params):
params = params.copy()
options = params.pop('OPTIONS').copy()
super().__init__(params)
self.context_processors = options.pop('context_processors', [])
environment = options.pop('environment', 'jinja2.Environment')
environment_cls = import_string(environment)
if 'loader' not in options:
options['loader'] = jinja2.FileSystemLoader(self.template_dirs)
options.setdefault('autoescape', True)
options.setdefault('auto_reload', settings.DEBUG)
options.setdefault('undefined',
jinja2.DebugUndefined if settings.DEBUG else jinja2.Undefined)
self.env = environment_cls(**options)
def from_string(self, template_code):
return Template(self.env.from_string(template_code), self)
def get_template(self, template_name):
try:
return Template(self.env.get_template(template_name), self)
except jinja2.TemplateNotFound as exc:
raise TemplateDoesNotExist(exc.name, backend=self) from exc
except jinja2.TemplateSyntaxError as exc:
new = TemplateSyntaxError(exc.args)
new.template_debug = get_exception_info(exc)
raise new from exc
@cached_property
def template_context_processors(self):
return [import_string(path) for path in self.context_processors]
class Template:
def __init__(self, template, backend):
self.template = template
self.backend = backend
self.origin = Origin(
name=template.filename, template_name=template.name,
)
def render(self, context=None, request=None):
from .utils import csrf_input_lazy, csrf_token_lazy
if context is None:
context = {}
if request is not None:
context['request'] = request
context['csrf_input'] = csrf_input_lazy(request)
context['csrf_token'] = csrf_token_lazy(request)
for context_processor in self.backend.template_context_processors:
context.update(context_processor(request))
try:
return self.template.render(context)
except jinja2.TemplateSyntaxError as exc:
new = TemplateSyntaxError(exc.args)
new.template_debug = get_exception_info(exc)
raise new from exc
class Origin:
"""
A container to hold debug information as described in the template API
documentation.
"""
def __init__(self, name, template_name):
self.name = name
self.template_name = template_name
def get_exception_info(exception):
"""
Format exception information for display on the debug page using the
structure described in the template API documentation.
"""
context_lines = 10
lineno = exception.lineno
source = exception.source
if source is None:
exception_file = Path(exception.filename)
if exception_file.exists():
source = exception_file.read_text()
if source is not None:
lines = list(enumerate(source.strip().split('\n'), start=1))
during = lines[lineno - 1][1]
total = len(lines)
top = max(0, lineno - context_lines - 1)
bottom = min(total, lineno + context_lines)
else:
during = ''
lines = []
total = top = bottom = 0
return {
'name': exception.filename,
'message': exception.message,
'source_lines': lines[top:bottom],
'line': lineno,
'before': '',
'during': during,
'after': '',
'total': total,
'top': top,
'bottom': bottom,
}
|
e3d4d9275552a924fdec3545d4f1830768fc5b4a95ec70e7ca18cb727256ffa4 | from importlib import import_module
from pkgutil import walk_packages
from django.apps import apps
from django.conf import settings
from django.template import TemplateDoesNotExist
from django.template.context import make_context
from django.template.engine import Engine
from django.template.library import InvalidTemplateLibrary
from .base import BaseEngine
class DjangoTemplates(BaseEngine):
app_dirname = 'templates'
def __init__(self, params):
params = params.copy()
options = params.pop('OPTIONS').copy()
options.setdefault('autoescape', True)
options.setdefault('debug', settings.DEBUG)
options.setdefault('file_charset', 'utf-8')
libraries = options.get('libraries', {})
options['libraries'] = self.get_templatetag_libraries(libraries)
super().__init__(params)
self.engine = Engine(self.dirs, self.app_dirs, **options)
def from_string(self, template_code):
return Template(self.engine.from_string(template_code), self)
def get_template(self, template_name):
try:
return Template(self.engine.get_template(template_name), self)
except TemplateDoesNotExist as exc:
reraise(exc, self)
def get_templatetag_libraries(self, custom_libraries):
"""
Return a collation of template tag libraries from installed
applications and the supplied custom_libraries argument.
"""
libraries = get_installed_libraries()
libraries.update(custom_libraries)
return libraries
class Template:
def __init__(self, template, backend):
self.template = template
self.backend = backend
@property
def origin(self):
return self.template.origin
def render(self, context=None, request=None):
context = make_context(context, request, autoescape=self.backend.engine.autoescape)
try:
return self.template.render(context)
except TemplateDoesNotExist as exc:
reraise(exc, self.backend)
def copy_exception(exc, backend=None):
"""
Create a new TemplateDoesNotExist. Preserve its declared attributes and
template debug data but discard __traceback__, __context__, and __cause__
to make this object suitable for keeping around (in a cache, for example).
"""
backend = backend or exc.backend
new = exc.__class__(*exc.args, tried=exc.tried, backend=backend, chain=exc.chain)
if hasattr(exc, 'template_debug'):
new.template_debug = exc.template_debug
return new
def reraise(exc, backend):
"""
Reraise TemplateDoesNotExist while maintaining template debug information.
"""
new = copy_exception(exc, backend)
raise new from exc
def get_template_tag_modules():
"""
Yield (module_name, module_path) pairs for all installed template tag
libraries.
"""
candidates = ['django.templatetags']
candidates.extend(
f'{app_config.name}.templatetags'
for app_config in apps.get_app_configs()
)
for candidate in candidates:
try:
pkg = import_module(candidate)
except ImportError:
# No templatetags package defined. This is safe to ignore.
continue
if hasattr(pkg, '__path__'):
for name in get_package_libraries(pkg):
yield name[len(candidate) + 1:], name
def get_installed_libraries():
"""
Return the built-in template tag libraries and those from installed
applications. Libraries are stored in a dictionary where keys are the
individual module names, not the full module paths. Example:
django.templatetags.i18n is stored as i18n.
"""
return {
module_name: full_name
for module_name, full_name in get_template_tag_modules()
}
def get_package_libraries(pkg):
"""
Recursively yield template tag libraries defined in submodules of a
package.
"""
for entry in walk_packages(pkg.__path__, pkg.__name__ + '.'):
try:
module = import_module(entry[1])
except ImportError as e:
raise InvalidTemplateLibrary(
"Invalid template library specified. ImportError raised when "
"trying to load '%s': %s" % (entry[1], e)
) from e
if hasattr(module, 'register'):
yield entry[1]
|
94b903119af2cbaa3ed516bf748cc9c343a9196ff41c729d63ff128a9d1315f9 | from django.apps.registry import apps as global_apps
from django.db import migrations, router
from .exceptions import InvalidMigrationPlan
from .loader import MigrationLoader
from .recorder import MigrationRecorder
from .state import ProjectState
class MigrationExecutor:
"""
End-to-end migration execution - load migrations and run them up or down
to a specified set of targets.
"""
def __init__(self, connection, progress_callback=None):
self.connection = connection
self.loader = MigrationLoader(self.connection)
self.recorder = MigrationRecorder(self.connection)
self.progress_callback = progress_callback
def migration_plan(self, targets, clean_start=False):
"""
Given a set of targets, return a list of (Migration instance, backwards?).
"""
plan = []
if clean_start:
applied = {}
else:
applied = dict(self.loader.applied_migrations)
for target in targets:
# If the target is (app_label, None), that means unmigrate everything
if target[1] is None:
for root in self.loader.graph.root_nodes():
if root[0] == target[0]:
for migration in self.loader.graph.backwards_plan(root):
if migration in applied:
plan.append((self.loader.graph.nodes[migration], True))
applied.pop(migration)
# If the migration is already applied, do backwards mode,
# otherwise do forwards mode.
elif target in applied:
# If the target is missing, it's likely a replaced migration.
# Reload the graph without replacements.
if (
self.loader.replace_migrations and
target not in self.loader.graph.node_map
):
self.loader.replace_migrations = False
self.loader.build_graph()
return self.migration_plan(targets, clean_start=clean_start)
# Don't migrate backwards all the way to the target node (that
# may roll back dependencies in other apps that don't need to
# be rolled back); instead roll back through target's immediate
# child(ren) in the same app, and no further.
next_in_app = sorted(
n for n in
self.loader.graph.node_map[target].children
if n[0] == target[0]
)
for node in next_in_app:
for migration in self.loader.graph.backwards_plan(node):
if migration in applied:
plan.append((self.loader.graph.nodes[migration], True))
applied.pop(migration)
else:
for migration in self.loader.graph.forwards_plan(target):
if migration not in applied:
plan.append((self.loader.graph.nodes[migration], False))
applied[migration] = self.loader.graph.nodes[migration]
return plan
def _create_project_state(self, with_applied_migrations=False):
"""
Create a project state including all the applications without
migrations and applied migrations if with_applied_migrations=True.
"""
state = ProjectState(real_apps=self.loader.unmigrated_apps)
if with_applied_migrations:
# Create the forwards plan Django would follow on an empty database
full_plan = self.migration_plan(self.loader.graph.leaf_nodes(), clean_start=True)
applied_migrations = {
self.loader.graph.nodes[key] for key in self.loader.applied_migrations
if key in self.loader.graph.nodes
}
for migration, _ in full_plan:
if migration in applied_migrations:
migration.mutate_state(state, preserve=False)
return state
def migrate(self, targets, plan=None, state=None, fake=False, fake_initial=False):
"""
Migrate the database up to the given targets.
Django first needs to create all project states before a migration is
(un)applied and in a second step run all the database operations.
"""
# The django_migrations table must be present to record applied
# migrations, but don't create it if there are no migrations to apply.
if plan == []:
if not self.recorder.has_table():
return self._create_project_state(with_applied_migrations=False)
else:
self.recorder.ensure_schema()
if plan is None:
plan = self.migration_plan(targets)
# Create the forwards plan Django would follow on an empty database
full_plan = self.migration_plan(self.loader.graph.leaf_nodes(), clean_start=True)
all_forwards = all(not backwards for mig, backwards in plan)
all_backwards = all(backwards for mig, backwards in plan)
if not plan:
if state is None:
# The resulting state should include applied migrations.
state = self._create_project_state(with_applied_migrations=True)
elif all_forwards == all_backwards:
# This should only happen if there's a mixed plan
raise InvalidMigrationPlan(
"Migration plans with both forwards and backwards migrations "
"are not supported. Please split your migration process into "
"separate plans of only forwards OR backwards migrations.",
plan
)
elif all_forwards:
if state is None:
# The resulting state should still include applied migrations.
state = self._create_project_state(with_applied_migrations=True)
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
else:
# No need to check for `elif all_backwards` here, as that condition
# would always evaluate to true.
state = self._migrate_all_backwards(plan, full_plan, fake=fake)
self.check_replacements()
return state
def _migrate_all_forwards(self, state, plan, full_plan, fake, fake_initial):
"""
Take a list of 2-tuples of the form (migration instance, False) and
apply them in the order they occur in the full_plan.
"""
migrations_to_run = {m[0] for m in plan}
for migration, _ in full_plan:
if not migrations_to_run:
# We remove every migration that we applied from these sets so
# that we can bail out once the last migration has been applied
# and don't always run until the very end of the migration
# process.
break
if migration in migrations_to_run:
if 'apps' not in state.__dict__:
if self.progress_callback:
self.progress_callback("render_start")
state.apps # Render all -- performance critical
if self.progress_callback:
self.progress_callback("render_success")
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
migrations_to_run.remove(migration)
return state
def _migrate_all_backwards(self, plan, full_plan, fake):
"""
Take a list of 2-tuples of the form (migration instance, True) and
unapply them in reverse order they occur in the full_plan.
Since unapplying a migration requires the project state prior to that
migration, Django will compute the migration states before each of them
in a first run over the plan and then unapply them in a second run over
the plan.
"""
migrations_to_run = {m[0] for m in plan}
# Holds all migration states prior to the migrations being unapplied
states = {}
state = self._create_project_state()
applied_migrations = {
self.loader.graph.nodes[key] for key in self.loader.applied_migrations
if key in self.loader.graph.nodes
}
if self.progress_callback:
self.progress_callback("render_start")
for migration, _ in full_plan:
if not migrations_to_run:
# We remove every migration that we applied from this set so
# that we can bail out once the last migration has been applied
# and don't always run until the very end of the migration
# process.
break
if migration in migrations_to_run:
if 'apps' not in state.__dict__:
state.apps # Render all -- performance critical
# The state before this migration
states[migration] = state
# The old state keeps as-is, we continue with the new state
state = migration.mutate_state(state, preserve=True)
migrations_to_run.remove(migration)
elif migration in applied_migrations:
# Only mutate the state if the migration is actually applied
# to make sure the resulting state doesn't include changes
# from unrelated migrations.
migration.mutate_state(state, preserve=False)
if self.progress_callback:
self.progress_callback("render_success")
for migration, _ in plan:
self.unapply_migration(states[migration], migration, fake=fake)
applied_migrations.remove(migration)
# Generate the post migration state by starting from the state before
# the last migration is unapplied and mutating it to include all the
# remaining applied migrations.
last_unapplied_migration = plan[-1][0]
state = states[last_unapplied_migration]
for index, (migration, _) in enumerate(full_plan):
if migration == last_unapplied_migration:
for migration, _ in full_plan[index:]:
if migration in applied_migrations:
migration.mutate_state(state, preserve=False)
break
return state
def apply_migration(self, state, migration, fake=False, fake_initial=False):
"""Run a migration forwards."""
migration_recorded = False
if self.progress_callback:
self.progress_callback("apply_start", migration, fake)
if not fake:
if fake_initial:
# Test to see if this is an already-applied initial migration
applied, state = self.detect_soft_applied(state, migration)
if applied:
fake = True
if not fake:
# Alright, do it normally
with self.connection.schema_editor(atomic=migration.atomic) as schema_editor:
state = migration.apply(state, schema_editor)
if not schema_editor.deferred_sql:
self.record_migration(migration)
migration_recorded = True
if not migration_recorded:
self.record_migration(migration)
# Report progress
if self.progress_callback:
self.progress_callback("apply_success", migration, fake)
return state
def record_migration(self, migration):
# For replacement migrations, record individual statuses
if migration.replaces:
for app_label, name in migration.replaces:
self.recorder.record_applied(app_label, name)
else:
self.recorder.record_applied(migration.app_label, migration.name)
def unapply_migration(self, state, migration, fake=False):
"""Run a migration backwards."""
if self.progress_callback:
self.progress_callback("unapply_start", migration, fake)
if not fake:
with self.connection.schema_editor(atomic=migration.atomic) as schema_editor:
state = migration.unapply(state, schema_editor)
# For replacement migrations, also record individual statuses.
if migration.replaces:
for app_label, name in migration.replaces:
self.recorder.record_unapplied(app_label, name)
self.recorder.record_unapplied(migration.app_label, migration.name)
# Report progress
if self.progress_callback:
self.progress_callback("unapply_success", migration, fake)
return state
def check_replacements(self):
"""
Mark replacement migrations applied if their replaced set all are.
Do this unconditionally on every migrate, rather than just when
migrations are applied or unapplied, to correctly handle the case
when a new squash migration is pushed to a deployment that already had
all its replaced migrations applied. In this case no new migration will
be applied, but the applied state of the squashed migration must be
maintained.
"""
applied = self.recorder.applied_migrations()
for key, migration in self.loader.replacements.items():
all_applied = all(m in applied for m in migration.replaces)
if all_applied and key not in applied:
self.recorder.record_applied(*key)
def detect_soft_applied(self, project_state, migration):
"""
Test whether a migration has been implicitly applied - that the
tables or columns it would create exist. This is intended only for use
on initial migrations (as it only looks for CreateModel and AddField).
"""
def should_skip_detecting_model(migration, model):
"""
No need to detect tables for proxy models, unmanaged models, or
models that can't be migrated on the current database.
"""
return (
model._meta.proxy or not model._meta.managed or not
router.allow_migrate(
self.connection.alias, migration.app_label,
model_name=model._meta.model_name,
)
)
if migration.initial is None:
# Bail if the migration isn't the first one in its app
if any(app == migration.app_label for app, name in migration.dependencies):
return False, project_state
elif migration.initial is False:
# Bail if it's NOT an initial migration
return False, project_state
if project_state is None:
after_state = self.loader.project_state((migration.app_label, migration.name), at_end=True)
else:
after_state = migration.mutate_state(project_state)
apps = after_state.apps
found_create_model_migration = False
found_add_field_migration = False
fold_identifier_case = self.connection.features.ignores_table_name_case
with self.connection.cursor() as cursor:
existing_table_names = set(self.connection.introspection.table_names(cursor))
if fold_identifier_case:
existing_table_names = {name.casefold() for name in existing_table_names}
# Make sure all create model and add field operations are done
for operation in migration.operations:
if isinstance(operation, migrations.CreateModel):
model = apps.get_model(migration.app_label, operation.name)
if model._meta.swapped:
# We have to fetch the model to test with from the
# main app cache, as it's not a direct dependency.
model = global_apps.get_model(model._meta.swapped)
if should_skip_detecting_model(migration, model):
continue
db_table = model._meta.db_table
if fold_identifier_case:
db_table = db_table.casefold()
if db_table not in existing_table_names:
return False, project_state
found_create_model_migration = True
elif isinstance(operation, migrations.AddField):
model = apps.get_model(migration.app_label, operation.model_name)
if model._meta.swapped:
# We have to fetch the model to test with from the
# main app cache, as it's not a direct dependency.
model = global_apps.get_model(model._meta.swapped)
if should_skip_detecting_model(migration, model):
continue
table = model._meta.db_table
field = model._meta.get_field(operation.name)
# Handle implicit many-to-many tables created by AddField.
if field.many_to_many:
through_db_table = field.remote_field.through._meta.db_table
if fold_identifier_case:
through_db_table = through_db_table.casefold()
if through_db_table not in existing_table_names:
return False, project_state
else:
found_add_field_migration = True
continue
with self.connection.cursor() as cursor:
columns = self.connection.introspection.get_table_description(cursor, table)
for column in columns:
field_column = field.column
column_name = column.name
if fold_identifier_case:
column_name = column_name.casefold()
field_column = field_column.casefold()
if column_name == field_column:
found_add_field_migration = True
break
else:
return False, project_state
# If we get this far and we found at least one CreateModel or AddField migration,
# the migration is considered implicitly applied.
return (found_create_model_migration or found_add_field_migration), after_state
|
a055f90fc990dfcbf9a273beba4a665cc50418dfe4bec61e1d1ce8fcbf7a8972 | import copy
from collections import defaultdict
from contextlib import contextmanager
from functools import partial
from django.apps import AppConfig
from django.apps.registry import Apps, apps as global_apps
from django.conf import settings
from django.core.exceptions import FieldDoesNotExist
from django.db import models
from django.db.migrations.utils import field_is_referenced, get_references
from django.db.models import NOT_PROVIDED
from django.db.models.fields.related import RECURSIVE_RELATIONSHIP_CONSTANT
from django.db.models.options import DEFAULT_NAMES, normalize_together
from django.db.models.utils import make_model_tuple
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from django.utils.version import get_docs_version
from .exceptions import InvalidBasesError
from .utils import resolve_relation
def _get_app_label_and_model_name(model, app_label=''):
if isinstance(model, str):
split = model.split('.', 1)
return tuple(split) if len(split) == 2 else (app_label, split[0])
else:
return model._meta.app_label, model._meta.model_name
def _get_related_models(m):
"""Return all models that have a direct relationship to the given model."""
related_models = [
subclass for subclass in m.__subclasses__()
if issubclass(subclass, models.Model)
]
related_fields_models = set()
for f in m._meta.get_fields(include_parents=True, include_hidden=True):
if f.is_relation and f.related_model is not None and not isinstance(f.related_model, str):
related_fields_models.add(f.model)
related_models.append(f.related_model)
# Reverse accessors of foreign keys to proxy models are attached to their
# concrete proxied model.
opts = m._meta
if opts.proxy and m in related_fields_models:
related_models.append(opts.concrete_model)
return related_models
def get_related_models_tuples(model):
"""
Return a list of typical (app_label, model_name) tuples for all related
models for the given model.
"""
return {
(rel_mod._meta.app_label, rel_mod._meta.model_name)
for rel_mod in _get_related_models(model)
}
def get_related_models_recursive(model):
"""
Return all models that have a direct or indirect relationship
to the given model.
Relationships are either defined by explicit relational fields, like
ForeignKey, ManyToManyField or OneToOneField, or by inheriting from another
model (a superclass is related to its subclasses, but not vice versa). Note,
however, that a model inheriting from a concrete model is also related to
its superclass through the implicit *_ptr OneToOneField on the subclass.
"""
seen = set()
queue = _get_related_models(model)
for rel_mod in queue:
rel_app_label, rel_model_name = rel_mod._meta.app_label, rel_mod._meta.model_name
if (rel_app_label, rel_model_name) in seen:
continue
seen.add((rel_app_label, rel_model_name))
queue.extend(_get_related_models(rel_mod))
return seen - {(model._meta.app_label, model._meta.model_name)}
class ProjectState:
"""
Represent the entire project's overall state. This is the item that is
passed around - do it here rather than at the app level so that cross-app
FKs/etc. resolve properly.
"""
def __init__(self, models=None, real_apps=None):
self.models = models or {}
# Apps to include from main registry, usually unmigrated ones
if real_apps is None:
real_apps = set()
else:
assert isinstance(real_apps, set)
self.real_apps = real_apps
self.is_delayed = False
# {remote_model_key: {model_key: {field_name: field}}}
self._relations = None
@property
def relations(self):
if self._relations is None:
self.resolve_fields_and_relations()
return self._relations
def add_model(self, model_state):
model_key = model_state.app_label, model_state.name_lower
self.models[model_key] = model_state
if self._relations is not None:
self.resolve_model_relations(model_key)
if 'apps' in self.__dict__: # hasattr would cache the property
self.reload_model(*model_key)
def remove_model(self, app_label, model_name):
model_key = app_label, model_name
del self.models[model_key]
if self._relations is not None:
self._relations.pop(model_key, None)
# Call list() since _relations can change size during iteration.
for related_model_key, model_relations in list(self._relations.items()):
model_relations.pop(model_key, None)
if not model_relations:
del self._relations[related_model_key]
if 'apps' in self.__dict__: # hasattr would cache the property
self.apps.unregister_model(*model_key)
# Need to do this explicitly since unregister_model() doesn't clear
# the cache automatically (#24513)
self.apps.clear_cache()
def rename_model(self, app_label, old_name, new_name):
# Add a new model.
old_name_lower = old_name.lower()
new_name_lower = new_name.lower()
renamed_model = self.models[app_label, old_name_lower].clone()
renamed_model.name = new_name
self.models[app_label, new_name_lower] = renamed_model
# Repoint all fields pointing to the old model to the new one.
old_model_tuple = (app_label, old_name_lower)
new_remote_model = f'{app_label}.{new_name}'
to_reload = set()
for model_state, name, field, reference in get_references(self, old_model_tuple):
changed_field = None
if reference.to:
changed_field = field.clone()
changed_field.remote_field.model = new_remote_model
if reference.through:
if changed_field is None:
changed_field = field.clone()
changed_field.remote_field.through = new_remote_model
if changed_field:
model_state.fields[name] = changed_field
to_reload.add((model_state.app_label, model_state.name_lower))
if self._relations is not None:
old_name_key = app_label, old_name_lower
new_name_key = app_label, new_name_lower
if old_name_key in self._relations:
self._relations[new_name_key] = self._relations.pop(old_name_key)
for model_relations in self._relations.values():
if old_name_key in model_relations:
model_relations[new_name_key] = model_relations.pop(old_name_key)
# Reload models related to old model before removing the old model.
self.reload_models(to_reload, delay=True)
# Remove the old model.
self.remove_model(app_label, old_name_lower)
self.reload_model(app_label, new_name_lower, delay=True)
def alter_model_options(self, app_label, model_name, options, option_keys=None):
model_state = self.models[app_label, model_name]
model_state.options = {**model_state.options, **options}
if option_keys:
for key in option_keys:
if key not in options:
model_state.options.pop(key, False)
self.reload_model(app_label, model_name, delay=True)
def alter_model_managers(self, app_label, model_name, managers):
model_state = self.models[app_label, model_name]
model_state.managers = list(managers)
self.reload_model(app_label, model_name, delay=True)
def _append_option(self, app_label, model_name, option_name, obj):
model_state = self.models[app_label, model_name]
model_state.options[option_name] = [*model_state.options[option_name], obj]
self.reload_model(app_label, model_name, delay=True)
def _remove_option(self, app_label, model_name, option_name, obj_name):
model_state = self.models[app_label, model_name]
objs = model_state.options[option_name]
model_state.options[option_name] = [obj for obj in objs if obj.name != obj_name]
self.reload_model(app_label, model_name, delay=True)
def add_index(self, app_label, model_name, index):
self._append_option(app_label, model_name, 'indexes', index)
def remove_index(self, app_label, model_name, index_name):
self._remove_option(app_label, model_name, 'indexes', index_name)
def add_constraint(self, app_label, model_name, constraint):
self._append_option(app_label, model_name, 'constraints', constraint)
def remove_constraint(self, app_label, model_name, constraint_name):
self._remove_option(app_label, model_name, 'constraints', constraint_name)
def add_field(self, app_label, model_name, name, field, preserve_default):
# If preserve default is off, don't use the default for future state.
if not preserve_default:
field = field.clone()
field.default = NOT_PROVIDED
else:
field = field
model_key = app_label, model_name
self.models[model_key].fields[name] = field
if self._relations is not None:
self.resolve_model_field_relations(model_key, name, field)
# Delay rendering of relationships if it's not a relational field.
delay = not field.is_relation
self.reload_model(*model_key, delay=delay)
def remove_field(self, app_label, model_name, name):
model_key = app_label, model_name
model_state = self.models[model_key]
old_field = model_state.fields.pop(name)
if self._relations is not None:
self.resolve_model_field_relations(model_key, name, old_field)
# Delay rendering of relationships if it's not a relational field.
delay = not old_field.is_relation
self.reload_model(*model_key, delay=delay)
def alter_field(self, app_label, model_name, name, field, preserve_default):
if not preserve_default:
field = field.clone()
field.default = NOT_PROVIDED
else:
field = field
model_key = app_label, model_name
fields = self.models[model_key].fields
if self._relations is not None:
old_field = fields.pop(name)
if old_field.is_relation:
self.resolve_model_field_relations(model_key, name, old_field)
fields[name] = field
if field.is_relation:
self.resolve_model_field_relations(model_key, name, field)
else:
fields[name] = field
# TODO: investigate if old relational fields must be reloaded or if
# it's sufficient if the new field is (#27737).
# Delay rendering of relationships if it's not a relational field and
# not referenced by a foreign key.
delay = (
not field.is_relation and
not field_is_referenced(self, model_key, (name, field))
)
self.reload_model(*model_key, delay=delay)
def rename_field(self, app_label, model_name, old_name, new_name):
model_key = app_label, model_name
model_state = self.models[model_key]
# Rename the field.
fields = model_state.fields
try:
found = fields.pop(old_name)
except KeyError:
raise FieldDoesNotExist(
f"{app_label}.{model_name} has no field named '{old_name}'"
)
fields[new_name] = found
for field in fields.values():
# Fix from_fields to refer to the new field.
from_fields = getattr(field, 'from_fields', None)
if from_fields:
field.from_fields = tuple([
new_name if from_field_name == old_name else from_field_name
for from_field_name in from_fields
])
# Fix index/unique_together to refer to the new field.
options = model_state.options
for option in ('index_together', 'unique_together'):
if option in options:
options[option] = [
[new_name if n == old_name else n for n in together]
for together in options[option]
]
# Fix to_fields to refer to the new field.
delay = True
references = get_references(self, model_key, (old_name, found))
for *_, field, reference in references:
delay = False
if reference.to:
remote_field, to_fields = reference.to
if getattr(remote_field, 'field_name', None) == old_name:
remote_field.field_name = new_name
if to_fields:
field.to_fields = tuple([
new_name if to_field_name == old_name else to_field_name
for to_field_name in to_fields
])
if self._relations is not None:
old_name_lower = old_name.lower()
new_name_lower = new_name.lower()
for to_model in self._relations.values():
if old_name_lower in to_model[model_key]:
field = to_model[model_key].pop(old_name_lower)
field.name = new_name_lower
to_model[model_key][new_name_lower] = field
self.reload_model(*model_key, delay=delay)
def _find_reload_model(self, app_label, model_name, delay=False):
if delay:
self.is_delayed = True
related_models = set()
try:
old_model = self.apps.get_model(app_label, model_name)
except LookupError:
pass
else:
# Get all relations to and from the old model before reloading,
# as _meta.apps may change
if delay:
related_models = get_related_models_tuples(old_model)
else:
related_models = get_related_models_recursive(old_model)
# Get all outgoing references from the model to be rendered
model_state = self.models[(app_label, model_name)]
# Directly related models are the models pointed to by ForeignKeys,
# OneToOneFields, and ManyToManyFields.
direct_related_models = set()
for field in model_state.fields.values():
if field.is_relation:
if field.remote_field.model == RECURSIVE_RELATIONSHIP_CONSTANT:
continue
rel_app_label, rel_model_name = _get_app_label_and_model_name(field.related_model, app_label)
direct_related_models.add((rel_app_label, rel_model_name.lower()))
# For all direct related models recursively get all related models.
related_models.update(direct_related_models)
for rel_app_label, rel_model_name in direct_related_models:
try:
rel_model = self.apps.get_model(rel_app_label, rel_model_name)
except LookupError:
pass
else:
if delay:
related_models.update(get_related_models_tuples(rel_model))
else:
related_models.update(get_related_models_recursive(rel_model))
# Include the model itself
related_models.add((app_label, model_name))
return related_models
def reload_model(self, app_label, model_name, delay=False):
if 'apps' in self.__dict__: # hasattr would cache the property
related_models = self._find_reload_model(app_label, model_name, delay)
self._reload(related_models)
def reload_models(self, models, delay=True):
if 'apps' in self.__dict__: # hasattr would cache the property
related_models = set()
for app_label, model_name in models:
related_models.update(self._find_reload_model(app_label, model_name, delay))
self._reload(related_models)
def _reload(self, related_models):
# Unregister all related models
with self.apps.bulk_update():
for rel_app_label, rel_model_name in related_models:
self.apps.unregister_model(rel_app_label, rel_model_name)
states_to_be_rendered = []
# Gather all models states of those models that will be rerendered.
# This includes:
# 1. All related models of unmigrated apps
for model_state in self.apps.real_models:
if (model_state.app_label, model_state.name_lower) in related_models:
states_to_be_rendered.append(model_state)
# 2. All related models of migrated apps
for rel_app_label, rel_model_name in related_models:
try:
model_state = self.models[rel_app_label, rel_model_name]
except KeyError:
pass
else:
states_to_be_rendered.append(model_state)
# Render all models
self.apps.render_multiple(states_to_be_rendered)
def update_model_field_relation(
self, model, model_key, field_name, field, concretes,
):
remote_model_key = resolve_relation(model, *model_key)
if remote_model_key[0] not in self.real_apps and remote_model_key in concretes:
remote_model_key = concretes[remote_model_key]
relations_to_remote_model = self._relations[remote_model_key]
if field_name in self.models[model_key].fields:
# The assert holds because it's a new relation, or an altered
# relation, in which case references have been removed by
# alter_field().
assert field_name not in relations_to_remote_model[model_key]
relations_to_remote_model[model_key][field_name] = field
else:
del relations_to_remote_model[model_key][field_name]
if not relations_to_remote_model[model_key]:
del relations_to_remote_model[model_key]
def resolve_model_field_relations(
self, model_key, field_name, field, concretes=None,
):
remote_field = field.remote_field
if not remote_field:
return
if concretes is None:
concretes, _ = self._get_concrete_models_mapping_and_proxy_models()
self.update_model_field_relation(
remote_field.model, model_key, field_name, field, concretes,
)
through = getattr(remote_field, 'through', None)
if not through:
return
self.update_model_field_relation(through, model_key, field_name, field, concretes)
def resolve_model_relations(self, model_key, concretes=None):
if concretes is None:
concretes, _ = self._get_concrete_models_mapping_and_proxy_models()
model_state = self.models[model_key]
for field_name, field in model_state.fields.items():
self.resolve_model_field_relations(model_key, field_name, field, concretes)
def resolve_fields_and_relations(self):
# Resolve fields.
for model_state in self.models.values():
for field_name, field in model_state.fields.items():
field.name = field_name
# Resolve relations.
# {remote_model_key: {model_key: {field_name: field}}}
self._relations = defaultdict(partial(defaultdict, dict))
concretes, proxies = self._get_concrete_models_mapping_and_proxy_models()
for model_key in concretes:
self.resolve_model_relations(model_key, concretes)
for model_key in proxies:
self._relations[model_key] = self._relations[concretes[model_key]]
def get_concrete_model_key(self, model):
concrete_models_mapping, _ = self._get_concrete_models_mapping_and_proxy_models()
model_key = make_model_tuple(model)
return concrete_models_mapping[model_key]
def _get_concrete_models_mapping_and_proxy_models(self):
concrete_models_mapping = {}
proxy_models = {}
# Split models to proxy and concrete models.
for model_key, model_state in self.models.items():
if model_state.options.get('proxy'):
proxy_models[model_key] = model_state
# Find a concrete model for the proxy.
concrete_models_mapping[model_key] = self._find_concrete_model_from_proxy(
proxy_models, model_state,
)
else:
concrete_models_mapping[model_key] = model_key
return concrete_models_mapping, proxy_models
def _find_concrete_model_from_proxy(self, proxy_models, model_state):
for base in model_state.bases:
if not (isinstance(base, str) or issubclass(base, models.Model)):
continue
base_key = make_model_tuple(base)
base_state = proxy_models.get(base_key)
if not base_state:
# Concrete model found, stop looking at bases.
return base_key
return self._find_concrete_model_from_proxy(proxy_models, base_state)
def clone(self):
"""Return an exact copy of this ProjectState."""
new_state = ProjectState(
models={k: v.clone() for k, v in self.models.items()},
real_apps=self.real_apps,
)
if 'apps' in self.__dict__:
new_state.apps = self.apps.clone()
new_state.is_delayed = self.is_delayed
return new_state
def clear_delayed_apps_cache(self):
if self.is_delayed and 'apps' in self.__dict__:
del self.__dict__['apps']
@cached_property
def apps(self):
return StateApps(self.real_apps, self.models)
@classmethod
def from_apps(cls, apps):
"""Take an Apps and return a ProjectState matching it."""
app_models = {}
for model in apps.get_models(include_swapped=True):
model_state = ModelState.from_model(model)
app_models[(model_state.app_label, model_state.name_lower)] = model_state
return cls(app_models)
def __eq__(self, other):
return self.models == other.models and self.real_apps == other.real_apps
class AppConfigStub(AppConfig):
"""Stub of an AppConfig. Only provides a label and a dict of models."""
def __init__(self, label):
self.apps = None
self.models = {}
# App-label and app-name are not the same thing, so technically passing
# in the label here is wrong. In practice, migrations don't care about
# the app name, but we need something unique, and the label works fine.
self.label = label
self.name = label
def import_models(self):
self.models = self.apps.all_models[self.label]
class StateApps(Apps):
"""
Subclass of the global Apps registry class to better handle dynamic model
additions and removals.
"""
def __init__(self, real_apps, models, ignore_swappable=False):
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
# FKs/M2Ms from real apps are also not included as they just
# mess things up with partial states (due to lack of dependencies)
self.real_models = []
for app_label in real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
self.real_models.append(ModelState.from_model(model, exclude_rels=True))
# Populate the app registry with a stub for each application.
app_labels = {model_state.app_label for model_state in models.values()}
app_configs = [AppConfigStub(label) for label in sorted([*real_apps, *app_labels])]
super().__init__(app_configs)
# These locks get in the way of copying as implemented in clone(),
# which is called whenever Django duplicates a StateApps before
# updating it.
self._lock = None
self.ready_event = None
self.render_multiple([*models.values(), *self.real_models])
# There shouldn't be any operations pending at this point.
from django.core.checks.model_checks import _check_lazy_references
ignore = {make_model_tuple(settings.AUTH_USER_MODEL)} if ignore_swappable else set()
errors = _check_lazy_references(self, ignore=ignore)
if errors:
raise ValueError("\n".join(error.msg for error in errors))
@contextmanager
def bulk_update(self):
# Avoid clearing each model's cache for each change. Instead, clear
# all caches when we're finished updating the model instances.
ready = self.ready
self.ready = False
try:
yield
finally:
self.ready = ready
self.clear_cache()
def render_multiple(self, model_states):
# We keep trying to render the models in a loop, ignoring invalid
# base errors, until the size of the unrendered models doesn't
# decrease by at least one, meaning there's a base dependency loop/
# missing base.
if not model_states:
return
# Prevent that all model caches are expired for each render.
with self.bulk_update():
unrendered_models = model_states
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self)
except InvalidBasesError:
new_unrendered_models.append(model)
if len(new_unrendered_models) == len(unrendered_models):
raise InvalidBasesError(
"Cannot resolve bases for %r\nThis can happen if you are inheriting models from an "
"app with migrations (e.g. contrib.auth)\n in an app with no migrations; see "
"https://docs.djangoproject.com/en/%s/topics/migrations/#dependencies "
"for more" % (new_unrendered_models, get_docs_version())
)
unrendered_models = new_unrendered_models
def clone(self):
"""Return a clone of this registry."""
clone = StateApps([], {})
clone.all_models = copy.deepcopy(self.all_models)
clone.app_configs = copy.deepcopy(self.app_configs)
# Set the pointer to the correct app registry.
for app_config in clone.app_configs.values():
app_config.apps = clone
# No need to actually clone them, they'll never change
clone.real_models = self.real_models
return clone
def register_model(self, app_label, model):
self.all_models[app_label][model._meta.model_name] = model
if app_label not in self.app_configs:
self.app_configs[app_label] = AppConfigStub(app_label)
self.app_configs[app_label].apps = self
self.app_configs[app_label].models[model._meta.model_name] = model
self.do_pending_operations(model)
self.clear_cache()
def unregister_model(self, app_label, model_name):
try:
del self.all_models[app_label][model_name]
del self.app_configs[app_label].models[model_name]
except KeyError:
pass
class ModelState:
"""
Represent a Django Model. Don't use the actual Model class as it's not
designed to have its options changed - instead, mutate this one and then
render it into a Model as required.
Note that while you are allowed to mutate .fields, you are not allowed
to mutate the Field instances inside there themselves - you must instead
assign new ones, as these are not detached during a clone.
"""
def __init__(self, app_label, name, fields, options=None, bases=None, managers=None):
self.app_label = app_label
self.name = name
self.fields = dict(fields)
self.options = options or {}
self.options.setdefault('indexes', [])
self.options.setdefault('constraints', [])
self.bases = bases or (models.Model,)
self.managers = managers or []
for name, field in self.fields.items():
# Sanity-check that fields are NOT already bound to a model.
if hasattr(field, 'model'):
raise ValueError(
'ModelState.fields cannot be bound to a model - "%s" is.' % name
)
# Sanity-check that relation fields are NOT referring to a model class.
if field.is_relation and hasattr(field.related_model, '_meta'):
raise ValueError(
'ModelState.fields cannot refer to a model class - "%s.to" does. '
'Use a string reference instead.' % name
)
if field.many_to_many and hasattr(field.remote_field.through, '_meta'):
raise ValueError(
'ModelState.fields cannot refer to a model class - "%s.through" does. '
'Use a string reference instead.' % name
)
# Sanity-check that indexes have their name set.
for index in self.options['indexes']:
if not index.name:
raise ValueError(
"Indexes passed to ModelState require a name attribute. "
"%r doesn't have one." % index
)
@cached_property
def name_lower(self):
return self.name.lower()
def get_field(self, field_name):
if field_name == '_order':
field_name = self.options.get('order_with_respect_to', field_name)
return self.fields[field_name]
@classmethod
def from_model(cls, model, exclude_rels=False):
"""Given a model, return a ModelState representing it."""
# Deconstruct the fields
fields = []
for field in model._meta.local_fields:
if getattr(field, "remote_field", None) and exclude_rels:
continue
if isinstance(field, models.OrderWrt):
continue
name = field.name
try:
fields.append((name, field.clone()))
except TypeError as e:
raise TypeError("Couldn't reconstruct field %s on %s: %s" % (
name,
model._meta.label,
e,
))
if not exclude_rels:
for field in model._meta.local_many_to_many:
name = field.name
try:
fields.append((name, field.clone()))
except TypeError as e:
raise TypeError("Couldn't reconstruct m2m field %s on %s: %s" % (
name,
model._meta.object_name,
e,
))
# Extract the options
options = {}
for name in DEFAULT_NAMES:
# Ignore some special options
if name in ["apps", "app_label"]:
continue
elif name in model._meta.original_attrs:
if name == "unique_together":
ut = model._meta.original_attrs["unique_together"]
options[name] = set(normalize_together(ut))
elif name == "index_together":
it = model._meta.original_attrs["index_together"]
options[name] = set(normalize_together(it))
elif name == "indexes":
indexes = [idx.clone() for idx in model._meta.indexes]
for index in indexes:
if not index.name:
index.set_name_with_model(model)
options['indexes'] = indexes
elif name == 'constraints':
options['constraints'] = [con.clone() for con in model._meta.constraints]
else:
options[name] = model._meta.original_attrs[name]
# If we're ignoring relationships, remove all field-listing model
# options (that option basically just means "make a stub model")
if exclude_rels:
for key in ["unique_together", "index_together", "order_with_respect_to"]:
if key in options:
del options[key]
# Private fields are ignored, so remove options that refer to them.
elif options.get('order_with_respect_to') in {field.name for field in model._meta.private_fields}:
del options['order_with_respect_to']
def flatten_bases(model):
bases = []
for base in model.__bases__:
if hasattr(base, "_meta") and base._meta.abstract:
bases.extend(flatten_bases(base))
else:
bases.append(base)
return bases
# We can't rely on __mro__ directly because we only want to flatten
# abstract models and not the whole tree. However by recursing on
# __bases__ we may end up with duplicates and ordering issues, we
# therefore discard any duplicates and reorder the bases according
# to their index in the MRO.
flattened_bases = sorted(set(flatten_bases(model)), key=lambda x: model.__mro__.index(x))
# Make our record
bases = tuple(
(
base._meta.label_lower
if hasattr(base, "_meta") else
base
)
for base in flattened_bases
)
# Ensure at least one base inherits from models.Model
if not any((isinstance(base, str) or issubclass(base, models.Model)) for base in bases):
bases = (models.Model,)
managers = []
manager_names = set()
default_manager_shim = None
for manager in model._meta.managers:
if manager.name in manager_names:
# Skip overridden managers.
continue
elif manager.use_in_migrations:
# Copy managers usable in migrations.
new_manager = copy.copy(manager)
new_manager._set_creation_counter()
elif manager is model._base_manager or manager is model._default_manager:
# Shim custom managers used as default and base managers.
new_manager = models.Manager()
new_manager.model = manager.model
new_manager.name = manager.name
if manager is model._default_manager:
default_manager_shim = new_manager
else:
continue
manager_names.add(manager.name)
managers.append((manager.name, new_manager))
# Ignore a shimmed default manager called objects if it's the only one.
if managers == [('objects', default_manager_shim)]:
managers = []
# Construct the new ModelState
return cls(
model._meta.app_label,
model._meta.object_name,
fields,
options,
bases,
managers,
)
def construct_managers(self):
"""Deep-clone the managers using deconstruction."""
# Sort all managers by their creation counter
sorted_managers = sorted(self.managers, key=lambda v: v[1].creation_counter)
for mgr_name, manager in sorted_managers:
as_manager, manager_path, qs_path, args, kwargs = manager.deconstruct()
if as_manager:
qs_class = import_string(qs_path)
yield mgr_name, qs_class.as_manager()
else:
manager_class = import_string(manager_path)
yield mgr_name, manager_class(*args, **kwargs)
def clone(self):
"""Return an exact copy of this ModelState."""
return self.__class__(
app_label=self.app_label,
name=self.name,
fields=dict(self.fields),
# Since options are shallow-copied here, operations such as
# AddIndex must replace their option (e.g 'indexes') rather
# than mutating it.
options=dict(self.options),
bases=self.bases,
managers=list(self.managers),
)
def render(self, apps):
"""Create a Model object from our current state into the given apps."""
# First, make a Meta object
meta_contents = {'app_label': self.app_label, 'apps': apps, **self.options}
meta = type("Meta", (), meta_contents)
# Then, work out our bases
try:
bases = tuple(
(apps.get_model(base) if isinstance(base, str) else base)
for base in self.bases
)
except LookupError:
raise InvalidBasesError("Cannot resolve one or more bases from %r" % (self.bases,))
# Clone fields for the body, add other bits.
body = {name: field.clone() for name, field in self.fields.items()}
body['Meta'] = meta
body['__module__'] = "__fake__"
# Restore managers
body.update(self.construct_managers())
# Then, make a Model object (apps.register_model is called in __new__)
return type(self.name, bases, body)
def get_index_by_name(self, name):
for index in self.options['indexes']:
if index.name == name:
return index
raise ValueError("No index named %s on model %s" % (name, self.name))
def get_constraint_by_name(self, name):
for constraint in self.options['constraints']:
if constraint.name == name:
return constraint
raise ValueError('No constraint named %s on model %s' % (name, self.name))
def __repr__(self):
return "<%s: '%s.%s'>" % (self.__class__.__name__, self.app_label, self.name)
def __eq__(self, other):
return (
(self.app_label == other.app_label) and
(self.name == other.name) and
(len(self.fields) == len(other.fields)) and
all(
k1 == k2 and f1.deconstruct()[1:] == f2.deconstruct()[1:]
for (k1, f1), (k2, f2) in zip(
sorted(self.fields.items()),
sorted(other.fields.items()),
)
) and
(self.options == other.options) and
(self.bases == other.bases) and
(self.managers == other.managers)
)
|
796e73262dbccb0d4ab1c743cd4d89af11bdbc4864910d05b019fc8f06658dd7 | import pkgutil
import sys
from importlib import import_module, reload
from django.apps import apps
from django.conf import settings
from django.db.migrations.graph import MigrationGraph
from django.db.migrations.recorder import MigrationRecorder
from .exceptions import (
AmbiguityError, BadMigrationError, InconsistentMigrationHistory,
NodeNotFoundError,
)
MIGRATIONS_MODULE_NAME = 'migrations'
class MigrationLoader:
"""
Load migration files from disk and their status from the database.
Migration files are expected to live in the "migrations" directory of
an app. Their names are entirely unimportant from a code perspective,
but will probably follow the 1234_name.py convention.
On initialization, this class will scan those directories, and open and
read the Python files, looking for a class called Migration, which should
inherit from django.db.migrations.Migration. See
django.db.migrations.migration for what that looks like.
Some migrations will be marked as "replacing" another set of migrations.
These are loaded into a separate set of migrations away from the main ones.
If all the migrations they replace are either unapplied or missing from
disk, then they are injected into the main set, replacing the named migrations.
Any dependency pointers to the replaced migrations are re-pointed to the
new migration.
This does mean that this class MUST also talk to the database as well as
to disk, but this is probably fine. We're already not just operating
in memory.
"""
def __init__(
self, connection, load=True, ignore_no_migrations=False,
replace_migrations=True,
):
self.connection = connection
self.disk_migrations = None
self.applied_migrations = None
self.ignore_no_migrations = ignore_no_migrations
self.replace_migrations = replace_migrations
if load:
self.build_graph()
@classmethod
def migrations_module(cls, app_label):
"""
Return the path to the migrations module for the specified app_label
and a boolean indicating if the module is specified in
settings.MIGRATION_MODULE.
"""
if app_label in settings.MIGRATION_MODULES:
return settings.MIGRATION_MODULES[app_label], True
else:
app_package_name = apps.get_app_config(app_label).name
return '%s.%s' % (app_package_name, MIGRATIONS_MODULE_NAME), False
def load_disk(self):
"""Load the migrations from all INSTALLED_APPS from disk."""
self.disk_migrations = {}
self.unmigrated_apps = set()
self.migrated_apps = set()
for app_config in apps.get_app_configs():
# Get the migrations module directory
module_name, explicit = self.migrations_module(app_config.label)
if module_name is None:
self.unmigrated_apps.add(app_config.label)
continue
was_loaded = module_name in sys.modules
try:
module = import_module(module_name)
except ModuleNotFoundError as e:
if (
(explicit and self.ignore_no_migrations) or
(not explicit and MIGRATIONS_MODULE_NAME in e.name.split('.'))
):
self.unmigrated_apps.add(app_config.label)
continue
raise
else:
# Module is not a package (e.g. migrations.py).
if not hasattr(module, '__path__'):
self.unmigrated_apps.add(app_config.label)
continue
# Empty directories are namespaces. Namespace packages have no
# __file__ and don't use a list for __path__. See
# https://docs.python.org/3/reference/import.html#namespace-packages
if (
getattr(module, '__file__', None) is None and
not isinstance(module.__path__, list)
):
self.unmigrated_apps.add(app_config.label)
continue
# Force a reload if it's already loaded (tests need this)
if was_loaded:
reload(module)
self.migrated_apps.add(app_config.label)
migration_names = {
name for _, name, is_pkg in pkgutil.iter_modules(module.__path__)
if not is_pkg and name[0] not in '_~'
}
# Load migrations
for migration_name in migration_names:
migration_path = '%s.%s' % (module_name, migration_name)
try:
migration_module = import_module(migration_path)
except ImportError as e:
if 'bad magic number' in str(e):
raise ImportError(
"Couldn't import %r as it appears to be a stale "
".pyc file." % migration_path
) from e
else:
raise
if not hasattr(migration_module, "Migration"):
raise BadMigrationError(
"Migration %s in app %s has no Migration class" % (migration_name, app_config.label)
)
self.disk_migrations[app_config.label, migration_name] = migration_module.Migration(
migration_name,
app_config.label,
)
def get_migration(self, app_label, name_prefix):
"""Return the named migration or raise NodeNotFoundError."""
return self.graph.nodes[app_label, name_prefix]
def get_migration_by_prefix(self, app_label, name_prefix):
"""
Return the migration(s) which match the given app label and name_prefix.
"""
# Do the search
results = []
for migration_app_label, migration_name in self.disk_migrations:
if migration_app_label == app_label and migration_name.startswith(name_prefix):
results.append((migration_app_label, migration_name))
if len(results) > 1:
raise AmbiguityError(
"There is more than one migration for '%s' with the prefix '%s'" % (app_label, name_prefix)
)
elif not results:
raise KeyError(
f"There is no migration for '{app_label}' with the prefix "
f"'{name_prefix}'"
)
else:
return self.disk_migrations[results[0]]
def check_key(self, key, current_app):
if (key[1] != "__first__" and key[1] != "__latest__") or key in self.graph:
return key
# Special-case __first__, which means "the first migration" for
# migrated apps, and is ignored for unmigrated apps. It allows
# makemigrations to declare dependencies on apps before they even have
# migrations.
if key[0] == current_app:
# Ignore __first__ references to the same app (#22325)
return
if key[0] in self.unmigrated_apps:
# This app isn't migrated, but something depends on it.
# The models will get auto-added into the state, though
# so we're fine.
return
if key[0] in self.migrated_apps:
try:
if key[1] == "__first__":
return self.graph.root_nodes(key[0])[0]
else: # "__latest__"
return self.graph.leaf_nodes(key[0])[0]
except IndexError:
if self.ignore_no_migrations:
return None
else:
raise ValueError("Dependency on app with no migrations: %s" % key[0])
raise ValueError("Dependency on unknown app: %s" % key[0])
def add_internal_dependencies(self, key, migration):
"""
Internal dependencies need to be added first to ensure `__first__`
dependencies find the correct root node.
"""
for parent in migration.dependencies:
# Ignore __first__ references to the same app.
if parent[0] == key[0] and parent[1] != '__first__':
self.graph.add_dependency(migration, key, parent, skip_validation=True)
def add_external_dependencies(self, key, migration):
for parent in migration.dependencies:
# Skip internal dependencies
if key[0] == parent[0]:
continue
parent = self.check_key(parent, key[0])
if parent is not None:
self.graph.add_dependency(migration, key, parent, skip_validation=True)
for child in migration.run_before:
child = self.check_key(child, key[0])
if child is not None:
self.graph.add_dependency(migration, child, key, skip_validation=True)
def build_graph(self):
"""
Build a migration dependency graph using both the disk and database.
You'll need to rebuild the graph if you apply migrations. This isn't
usually a problem as generally migration stuff runs in a one-shot process.
"""
# Load disk data
self.load_disk()
# Load database data
if self.connection is None:
self.applied_migrations = {}
else:
recorder = MigrationRecorder(self.connection)
self.applied_migrations = recorder.applied_migrations()
# To start, populate the migration graph with nodes for ALL migrations
# and their dependencies. Also make note of replacing migrations at this step.
self.graph = MigrationGraph()
self.replacements = {}
for key, migration in self.disk_migrations.items():
self.graph.add_node(key, migration)
# Replacing migrations.
if migration.replaces:
self.replacements[key] = migration
for key, migration in self.disk_migrations.items():
# Internal (same app) dependencies.
self.add_internal_dependencies(key, migration)
# Add external dependencies now that the internal ones have been resolved.
for key, migration in self.disk_migrations.items():
self.add_external_dependencies(key, migration)
# Carry out replacements where possible and if enabled.
if self.replace_migrations:
for key, migration in self.replacements.items():
# Get applied status of each of this migration's replacement
# targets.
applied_statuses = [(target in self.applied_migrations) for target in migration.replaces]
# The replacing migration is only marked as applied if all of
# its replacement targets are.
if all(applied_statuses):
self.applied_migrations[key] = migration
else:
self.applied_migrations.pop(key, None)
# A replacing migration can be used if either all or none of
# its replacement targets have been applied.
if all(applied_statuses) or (not any(applied_statuses)):
self.graph.remove_replaced_nodes(key, migration.replaces)
else:
# This replacing migration cannot be used because it is
# partially applied. Remove it from the graph and remap
# dependencies to it (#25945).
self.graph.remove_replacement_node(key, migration.replaces)
# Ensure the graph is consistent.
try:
self.graph.validate_consistency()
except NodeNotFoundError as exc:
# Check if the missing node could have been replaced by any squash
# migration but wasn't because the squash migration was partially
# applied before. In that case raise a more understandable exception
# (#23556).
# Get reverse replacements.
reverse_replacements = {}
for key, migration in self.replacements.items():
for replaced in migration.replaces:
reverse_replacements.setdefault(replaced, set()).add(key)
# Try to reraise exception with more detail.
if exc.node in reverse_replacements:
candidates = reverse_replacements.get(exc.node, set())
is_replaced = any(candidate in self.graph.nodes for candidate in candidates)
if not is_replaced:
tries = ', '.join('%s.%s' % c for c in candidates)
raise NodeNotFoundError(
"Migration {0} depends on nonexistent node ('{1}', '{2}'). "
"Django tried to replace migration {1}.{2} with any of [{3}] "
"but wasn't able to because some of the replaced migrations "
"are already applied.".format(
exc.origin, exc.node[0], exc.node[1], tries
),
exc.node
) from exc
raise
self.graph.ensure_not_cyclic()
def check_consistent_history(self, connection):
"""
Raise InconsistentMigrationHistory if any applied migrations have
unapplied dependencies.
"""
recorder = MigrationRecorder(connection)
applied = recorder.applied_migrations()
for migration in applied:
# If the migration is unknown, skip it.
if migration not in self.graph.nodes:
continue
for parent in self.graph.node_map[migration].parents:
if parent not in applied:
# Skip unapplied squashed migrations that have all of their
# `replaces` applied.
if parent in self.replacements:
if all(m in applied for m in self.replacements[parent].replaces):
continue
raise InconsistentMigrationHistory(
"Migration {}.{} is applied before its dependency "
"{}.{} on database '{}'.".format(
migration[0], migration[1], parent[0], parent[1],
connection.alias,
)
)
def detect_conflicts(self):
"""
Look through the loaded graph and detect any conflicts - apps
with more than one leaf migration. Return a dict of the app labels
that conflict with the migration names that conflict.
"""
seen_apps = {}
conflicting_apps = set()
for app_label, migration_name in self.graph.leaf_nodes():
if app_label in seen_apps:
conflicting_apps.add(app_label)
seen_apps.setdefault(app_label, set()).add(migration_name)
return {app_label: sorted(seen_apps[app_label]) for app_label in conflicting_apps}
def project_state(self, nodes=None, at_end=True):
"""
Return a ProjectState object representing the most recent state
that the loaded migrations represent.
See graph.make_state() for the meaning of "nodes" and "at_end".
"""
return self.graph.make_state(nodes=nodes, at_end=at_end, real_apps=self.unmigrated_apps)
def collect_sql(self, plan):
"""
Take a migration plan and return a list of collected SQL statements
that represent the best-efforts version of that plan.
"""
statements = []
state = None
for migration, backwards in plan:
with self.connection.schema_editor(collect_sql=True, atomic=migration.atomic) as schema_editor:
if state is None:
state = self.project_state((migration.app_label, migration.name), at_end=False)
if not backwards:
state = migration.apply(state, schema_editor, collect_sql=True)
else:
state = migration.unapply(state, schema_editor, collect_sql=True)
statements.extend(schema_editor.collected_sql)
return statements
|
49b347bb84db713014c57717b81776eaae68adb4f2bb0a14fe007b4f79c52bad | import datetime
import importlib
import os
import sys
from django.apps import apps
from django.core.management.base import OutputWrapper
from django.db.models import NOT_PROVIDED
from django.utils import timezone
from django.utils.version import get_docs_version
from .loader import MigrationLoader
class MigrationQuestioner:
"""
Give the autodetector responses to questions it might have.
This base class has a built-in noninteractive mode, but the
interactive subclass is what the command-line arguments will use.
"""
def __init__(self, defaults=None, specified_apps=None, dry_run=None):
self.defaults = defaults or {}
self.specified_apps = specified_apps or set()
self.dry_run = dry_run
def ask_initial(self, app_label):
"""Should we create an initial migration for the app?"""
# If it was specified on the command line, definitely true
if app_label in self.specified_apps:
return True
# Otherwise, we look to see if it has a migrations module
# without any Python files in it, apart from __init__.py.
# Apps from the new app template will have these; the Python
# file check will ensure we skip South ones.
try:
app_config = apps.get_app_config(app_label)
except LookupError: # It's a fake app.
return self.defaults.get("ask_initial", False)
migrations_import_path, _ = MigrationLoader.migrations_module(app_config.label)
if migrations_import_path is None:
# It's an application with migrations disabled.
return self.defaults.get("ask_initial", False)
try:
migrations_module = importlib.import_module(migrations_import_path)
except ImportError:
return self.defaults.get("ask_initial", False)
else:
if getattr(migrations_module, "__file__", None):
filenames = os.listdir(os.path.dirname(migrations_module.__file__))
elif hasattr(migrations_module, "__path__"):
if len(migrations_module.__path__) > 1:
return False
filenames = os.listdir(list(migrations_module.__path__)[0])
return not any(x.endswith(".py") for x in filenames if x != "__init__.py")
def ask_not_null_addition(self, field_name, model_name):
"""Adding a NOT NULL field to a model."""
# None means quit
return None
def ask_not_null_alteration(self, field_name, model_name):
"""Changing a NULL field to NOT NULL."""
# None means quit
return None
def ask_rename(self, model_name, old_name, new_name, field_instance):
"""Was this field really renamed?"""
return self.defaults.get("ask_rename", False)
def ask_rename_model(self, old_model_state, new_model_state):
"""Was this model really renamed?"""
return self.defaults.get("ask_rename_model", False)
def ask_merge(self, app_label):
"""Should these migrations really be merged?"""
return self.defaults.get("ask_merge", False)
def ask_auto_now_add_addition(self, field_name, model_name):
"""Adding an auto_now_add field to a model."""
# None means quit
return None
def ask_unique_callable_default_addition(self, field_name, model_name):
"""Adding a unique field with a callable default."""
# None means continue.
return None
class InteractiveMigrationQuestioner(MigrationQuestioner):
def __init__(self, defaults=None, specified_apps=None, dry_run=None, prompt_output=None):
super().__init__(defaults=defaults, specified_apps=specified_apps, dry_run=dry_run)
self.prompt_output = prompt_output or OutputWrapper(sys.stdout)
def _boolean_input(self, question, default=None):
self.prompt_output.write(f'{question} ', ending='')
result = input()
if not result and default is not None:
return default
while not result or result[0].lower() not in "yn":
self.prompt_output.write('Please answer yes or no: ', ending='')
result = input()
return result[0].lower() == "y"
def _choice_input(self, question, choices):
self.prompt_output.write(f'{question}')
for i, choice in enumerate(choices):
self.prompt_output.write(' %s) %s' % (i + 1, choice))
self.prompt_output.write('Select an option: ', ending='')
result = input()
while True:
try:
value = int(result)
except ValueError:
pass
else:
if 0 < value <= len(choices):
return value
self.prompt_output.write('Please select a valid option: ', ending='')
result = input()
def _ask_default(self, default=''):
"""
Prompt for a default value.
The ``default`` argument allows providing a custom default value (as a
string) which will be shown to the user and used as the return value
if the user doesn't provide any other input.
"""
self.prompt_output.write('Please enter the default value as valid Python.')
if default:
self.prompt_output.write(
f"Accept the default '{default}' by pressing 'Enter' or "
f"provide another value."
)
self.prompt_output.write(
'The datetime and django.utils.timezone modules are available, so '
'it is possible to provide e.g. timezone.now as a value.'
)
self.prompt_output.write("Type 'exit' to exit this prompt")
while True:
if default:
prompt = "[default: {}] >>> ".format(default)
else:
prompt = ">>> "
self.prompt_output.write(prompt, ending='')
code = input()
if not code and default:
code = default
if not code:
self.prompt_output.write("Please enter some code, or 'exit' (without quotes) to exit.")
elif code == "exit":
sys.exit(1)
else:
try:
return eval(code, {}, {'datetime': datetime, 'timezone': timezone})
except (SyntaxError, NameError) as e:
self.prompt_output.write('Invalid input: %s' % e)
def ask_not_null_addition(self, field_name, model_name):
"""Adding a NOT NULL field to a model."""
if not self.dry_run:
choice = self._choice_input(
f"It is impossible to add a non-nullable field '{field_name}' "
f"to {model_name} without specifying a default. This is "
f"because the database needs something to populate existing "
f"rows.\n"
f"Please select a fix:",
[
("Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"),
'Quit and manually define a default value in models.py.',
]
)
if choice == 2:
sys.exit(3)
else:
return self._ask_default()
return None
def ask_not_null_alteration(self, field_name, model_name):
"""Changing a NULL field to NOT NULL."""
if not self.dry_run:
choice = self._choice_input(
f"It is impossible to change a nullable field '{field_name}' "
f"on {model_name} to non-nullable without providing a "
f"default. This is because the database needs something to "
f"populate existing rows.\n"
f"Please select a fix:",
[
("Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"),
'Ignore for now. Existing rows that contain NULL values '
'will have to be handled manually, for example with a '
'RunPython or RunSQL operation.',
'Quit and manually define a default value in models.py.',
]
)
if choice == 2:
return NOT_PROVIDED
elif choice == 3:
sys.exit(3)
else:
return self._ask_default()
return None
def ask_rename(self, model_name, old_name, new_name, field_instance):
"""Was this field really renamed?"""
msg = 'Was %s.%s renamed to %s.%s (a %s)? [y/N]'
return self._boolean_input(msg % (model_name, old_name, model_name, new_name,
field_instance.__class__.__name__), False)
def ask_rename_model(self, old_model_state, new_model_state):
"""Was this model really renamed?"""
msg = 'Was the model %s.%s renamed to %s? [y/N]'
return self._boolean_input(msg % (old_model_state.app_label, old_model_state.name,
new_model_state.name), False)
def ask_merge(self, app_label):
return self._boolean_input(
"\nMerging will only work if the operations printed above do not conflict\n" +
"with each other (working on different fields or models)\n" +
'Should these migration branches be merged? [y/N]',
False,
)
def ask_auto_now_add_addition(self, field_name, model_name):
"""Adding an auto_now_add field to a model."""
if not self.dry_run:
choice = self._choice_input(
f"It is impossible to add the field '{field_name}' with "
f"'auto_now_add=True' to {model_name} without providing a "
f"default. This is because the database needs something to "
f"populate existing rows.\n",
[
'Provide a one-off default now which will be set on all '
'existing rows',
'Quit and manually define a default value in models.py.',
]
)
if choice == 2:
sys.exit(3)
else:
return self._ask_default(default='timezone.now')
return None
def ask_unique_callable_default_addition(self, field_name, model_name):
"""Adding a unique field with a callable default."""
if not self.dry_run:
version = get_docs_version()
choice = self._choice_input(
f'Callable default on unique field {model_name}.{field_name} '
f'will not generate unique values upon migrating.\n'
f'Please choose how to proceed:\n',
[
f'Continue making this migration as the first step in '
f'writing a manual migration to generate unique values '
f'described here: '
f'https://docs.djangoproject.com/en/{version}/howto/'
f'writing-migrations/#migrations-that-add-unique-fields.',
'Quit and edit field options in models.py.',
],
)
if choice == 2:
sys.exit(3)
return None
class NonInteractiveMigrationQuestioner(MigrationQuestioner):
def __init__(
self, defaults=None, specified_apps=None, dry_run=None, verbosity=1,
log=None,
):
self.verbosity = verbosity
self.log = log
super().__init__(
defaults=defaults, specified_apps=specified_apps, dry_run=dry_run,
)
def log_lack_of_migration(self, field_name, model_name, reason):
if self.verbosity > 0:
self.log(
f"Field '{field_name}' on model '{model_name}' not migrated: "
f"{reason}."
)
def ask_not_null_addition(self, field_name, model_name):
# We can't ask the user, so act like the user aborted.
self.log_lack_of_migration(
field_name,
model_name,
'it is impossible to add a non-nullable field without specifying '
'a default',
)
sys.exit(3)
def ask_not_null_alteration(self, field_name, model_name):
# We can't ask the user, so set as not provided.
self.log(
f"Field '{field_name}' on model '{model_name}' given a default of "
f"NOT PROVIDED and must be corrected."
)
return NOT_PROVIDED
def ask_auto_now_add_addition(self, field_name, model_name):
# We can't ask the user, so act like the user aborted.
self.log_lack_of_migration(
field_name,
model_name,
"it is impossible to add a field with 'auto_now_add=True' without "
"specifying a default",
)
sys.exit(3)
|
334273ebb68f6fc80c7e80b08edcb585616ed5a7c49a91a85045a1a8254998e2 | import functools
import re
from itertools import chain
from django.conf import settings
from django.db import models
from django.db.migrations import operations
from django.db.migrations.migration import Migration
from django.db.migrations.operations.models import AlterModelOptions
from django.db.migrations.optimizer import MigrationOptimizer
from django.db.migrations.questioner import MigrationQuestioner
from django.db.migrations.utils import (
COMPILED_REGEX_TYPE, RegexObject, resolve_relation,
)
from django.utils.topological_sort import stable_topological_sort
class MigrationAutodetector:
"""
Take a pair of ProjectStates and compare them to see what the first would
need doing to make it match the second (the second usually being the
project's current state).
Note that this naturally operates on entire projects at a time,
as it's likely that changes interact (for example, you can't
add a ForeignKey without having a migration to add the table it
depends on first). A user interface may offer single-app usage
if it wishes, with the caveat that it may not always be possible.
"""
def __init__(self, from_state, to_state, questioner=None):
self.from_state = from_state
self.to_state = to_state
self.questioner = questioner or MigrationQuestioner()
self.existing_apps = {app for app, model in from_state.models}
def changes(self, graph, trim_to_apps=None, convert_apps=None, migration_name=None):
"""
Main entry point to produce a list of applicable changes.
Take a graph to base names on and an optional set of apps
to try and restrict to (restriction is not guaranteed)
"""
changes = self._detect_changes(convert_apps, graph)
changes = self.arrange_for_graph(changes, graph, migration_name)
if trim_to_apps:
changes = self._trim_to_apps(changes, trim_to_apps)
return changes
def deep_deconstruct(self, obj):
"""
Recursive deconstruction for a field and its arguments.
Used for full comparison for rename/alter; sometimes a single-level
deconstruction will not compare correctly.
"""
if isinstance(obj, list):
return [self.deep_deconstruct(value) for value in obj]
elif isinstance(obj, tuple):
return tuple(self.deep_deconstruct(value) for value in obj)
elif isinstance(obj, dict):
return {
key: self.deep_deconstruct(value)
for key, value in obj.items()
}
elif isinstance(obj, functools.partial):
return (obj.func, self.deep_deconstruct(obj.args), self.deep_deconstruct(obj.keywords))
elif isinstance(obj, COMPILED_REGEX_TYPE):
return RegexObject(obj)
elif isinstance(obj, type):
# If this is a type that implements 'deconstruct' as an instance method,
# avoid treating this as being deconstructible itself - see #22951
return obj
elif hasattr(obj, 'deconstruct'):
deconstructed = obj.deconstruct()
if isinstance(obj, models.Field):
# we have a field which also returns a name
deconstructed = deconstructed[1:]
path, args, kwargs = deconstructed
return (
path,
[self.deep_deconstruct(value) for value in args],
{
key: self.deep_deconstruct(value)
for key, value in kwargs.items()
},
)
else:
return obj
def only_relation_agnostic_fields(self, fields):
"""
Return a definition of the fields that ignores field names and
what related fields actually relate to. Used for detecting renames (as
the related fields change during renames).
"""
fields_def = []
for name, field in sorted(fields.items()):
deconstruction = self.deep_deconstruct(field)
if field.remote_field and field.remote_field.model:
deconstruction[2].pop('to', None)
fields_def.append(deconstruction)
return fields_def
def _detect_changes(self, convert_apps=None, graph=None):
"""
Return a dict of migration plans which will achieve the
change from from_state to to_state. The dict has app labels
as keys and a list of migrations as values.
The resulting migrations aren't specially named, but the names
do matter for dependencies inside the set.
convert_apps is the list of apps to convert to use migrations
(i.e. to make initial migrations for, in the usual case)
graph is an optional argument that, if provided, can help improve
dependency generation and avoid potential circular dependencies.
"""
# The first phase is generating all the operations for each app
# and gathering them into a big per-app list.
# Then go through that list, order it, and split into migrations to
# resolve dependencies caused by M2Ms and FKs.
self.generated_operations = {}
self.altered_indexes = {}
self.altered_constraints = {}
# Prepare some old/new state and model lists, separating
# proxy models and ignoring unmigrated apps.
self.old_model_keys = set()
self.old_proxy_keys = set()
self.old_unmanaged_keys = set()
self.new_model_keys = set()
self.new_proxy_keys = set()
self.new_unmanaged_keys = set()
for (app_label, model_name), model_state in self.from_state.models.items():
if not model_state.options.get('managed', True):
self.old_unmanaged_keys.add((app_label, model_name))
elif app_label not in self.from_state.real_apps:
if model_state.options.get('proxy'):
self.old_proxy_keys.add((app_label, model_name))
else:
self.old_model_keys.add((app_label, model_name))
for (app_label, model_name), model_state in self.to_state.models.items():
if not model_state.options.get('managed', True):
self.new_unmanaged_keys.add((app_label, model_name))
elif (
app_label not in self.from_state.real_apps or
(convert_apps and app_label in convert_apps)
):
if model_state.options.get('proxy'):
self.new_proxy_keys.add((app_label, model_name))
else:
self.new_model_keys.add((app_label, model_name))
self.from_state.resolve_fields_and_relations()
self.to_state.resolve_fields_and_relations()
# Renames have to come first
self.generate_renamed_models()
# Prepare lists of fields and generate through model map
self._prepare_field_lists()
self._generate_through_model_map()
# Generate non-rename model operations
self.generate_deleted_models()
self.generate_created_models()
self.generate_deleted_proxies()
self.generate_created_proxies()
self.generate_altered_options()
self.generate_altered_managers()
# Create the altered indexes and store them in self.altered_indexes.
# This avoids the same computation in generate_removed_indexes()
# and generate_added_indexes().
self.create_altered_indexes()
self.create_altered_constraints()
# Generate index removal operations before field is removed
self.generate_removed_constraints()
self.generate_removed_indexes()
# Generate field renaming operations.
self.generate_renamed_fields()
# Generate removal of foo together.
self.generate_removed_altered_unique_together()
self.generate_removed_altered_index_together()
# Generate field operations.
self.generate_removed_fields()
self.generate_added_fields()
self.generate_altered_fields()
self.generate_altered_order_with_respect_to()
self.generate_altered_unique_together()
self.generate_altered_index_together()
self.generate_added_indexes()
self.generate_added_constraints()
self.generate_altered_db_table()
self._sort_migrations()
self._build_migration_list(graph)
self._optimize_migrations()
return self.migrations
def _prepare_field_lists(self):
"""
Prepare field lists and a list of the fields that used through models
in the old state so dependencies can be made from the through model
deletion to the field that uses it.
"""
self.kept_model_keys = self.old_model_keys & self.new_model_keys
self.kept_proxy_keys = self.old_proxy_keys & self.new_proxy_keys
self.kept_unmanaged_keys = self.old_unmanaged_keys & self.new_unmanaged_keys
self.through_users = {}
self.old_field_keys = {
(app_label, model_name, field_name)
for app_label, model_name in self.kept_model_keys
for field_name in self.from_state.models[
app_label,
self.renamed_models.get((app_label, model_name), model_name)
].fields
}
self.new_field_keys = {
(app_label, model_name, field_name)
for app_label, model_name in self.kept_model_keys
for field_name in self.to_state.models[app_label, model_name].fields
}
def _generate_through_model_map(self):
"""Through model map generation."""
for app_label, model_name in sorted(self.old_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
for field_name, field in old_model_state.fields.items():
if hasattr(field, 'remote_field') and getattr(field.remote_field, 'through', None):
through_key = resolve_relation(field.remote_field.through, app_label, model_name)
self.through_users[through_key] = (app_label, old_model_name, field_name)
@staticmethod
def _resolve_dependency(dependency):
"""
Return the resolved dependency and a boolean denoting whether or not
it was swappable.
"""
if dependency[0] != '__setting__':
return dependency, False
resolved_app_label, resolved_object_name = getattr(settings, dependency[1]).split('.')
return (resolved_app_label, resolved_object_name.lower()) + dependency[2:], True
def _build_migration_list(self, graph=None):
"""
Chop the lists of operations up into migrations with dependencies on
each other. Do this by going through an app's list of operations until
one is found that has an outgoing dependency that isn't in another
app's migration yet (hasn't been chopped off its list). Then chop off
the operations before it into a migration and move onto the next app.
If the loops completes without doing anything, there's a circular
dependency (which _should_ be impossible as the operations are
all split at this point so they can't depend and be depended on).
"""
self.migrations = {}
num_ops = sum(len(x) for x in self.generated_operations.values())
chop_mode = False
while num_ops:
# On every iteration, we step through all the apps and see if there
# is a completed set of operations.
# If we find that a subset of the operations are complete we can
# try to chop it off from the rest and continue, but we only
# do this if we've already been through the list once before
# without any chopping and nothing has changed.
for app_label in sorted(self.generated_operations):
chopped = []
dependencies = set()
for operation in list(self.generated_operations[app_label]):
deps_satisfied = True
operation_dependencies = set()
for dep in operation._auto_deps:
# Temporarily resolve the swappable dependency to
# prevent circular references. While keeping the
# dependency checks on the resolved model, add the
# swappable dependencies.
original_dep = dep
dep, is_swappable_dep = self._resolve_dependency(dep)
if dep[0] != app_label:
# External app dependency. See if it's not yet
# satisfied.
for other_operation in self.generated_operations.get(dep[0], []):
if self.check_dependency(other_operation, dep):
deps_satisfied = False
break
if not deps_satisfied:
break
else:
if is_swappable_dep:
operation_dependencies.add((original_dep[0], original_dep[1]))
elif dep[0] in self.migrations:
operation_dependencies.add((dep[0], self.migrations[dep[0]][-1].name))
else:
# If we can't find the other app, we add a first/last dependency,
# but only if we've already been through once and checked everything
if chop_mode:
# If the app already exists, we add a dependency on the last migration,
# as we don't know which migration contains the target field.
# If it's not yet migrated or has no migrations, we use __first__
if graph and graph.leaf_nodes(dep[0]):
operation_dependencies.add(graph.leaf_nodes(dep[0])[0])
else:
operation_dependencies.add((dep[0], "__first__"))
else:
deps_satisfied = False
if deps_satisfied:
chopped.append(operation)
dependencies.update(operation_dependencies)
del self.generated_operations[app_label][0]
else:
break
# Make a migration! Well, only if there's stuff to put in it
if dependencies or chopped:
if not self.generated_operations[app_label] or chop_mode:
subclass = type("Migration", (Migration,), {"operations": [], "dependencies": []})
instance = subclass("auto_%i" % (len(self.migrations.get(app_label, [])) + 1), app_label)
instance.dependencies = list(dependencies)
instance.operations = chopped
instance.initial = app_label not in self.existing_apps
self.migrations.setdefault(app_label, []).append(instance)
chop_mode = False
else:
self.generated_operations[app_label] = chopped + self.generated_operations[app_label]
new_num_ops = sum(len(x) for x in self.generated_operations.values())
if new_num_ops == num_ops:
if not chop_mode:
chop_mode = True
else:
raise ValueError("Cannot resolve operation dependencies: %r" % self.generated_operations)
num_ops = new_num_ops
def _sort_migrations(self):
"""
Reorder to make things possible. Reordering may be needed so FKs work
nicely inside the same app.
"""
for app_label, ops in sorted(self.generated_operations.items()):
# construct a dependency graph for intra-app dependencies
dependency_graph = {op: set() for op in ops}
for op in ops:
for dep in op._auto_deps:
# Resolve intra-app dependencies to handle circular
# references involving a swappable model.
dep = self._resolve_dependency(dep)[0]
if dep[0] == app_label:
for op2 in ops:
if self.check_dependency(op2, dep):
dependency_graph[op].add(op2)
# we use a stable sort for deterministic tests & general behavior
self.generated_operations[app_label] = stable_topological_sort(ops, dependency_graph)
def _optimize_migrations(self):
# Add in internal dependencies among the migrations
for app_label, migrations in self.migrations.items():
for m1, m2 in zip(migrations, migrations[1:]):
m2.dependencies.append((app_label, m1.name))
# De-dupe dependencies
for migrations in self.migrations.values():
for migration in migrations:
migration.dependencies = list(set(migration.dependencies))
# Optimize migrations
for app_label, migrations in self.migrations.items():
for migration in migrations:
migration.operations = MigrationOptimizer().optimize(migration.operations, app_label)
def check_dependency(self, operation, dependency):
"""
Return True if the given operation depends on the given dependency,
False otherwise.
"""
# Created model
if dependency[2] is None and dependency[3] is True:
return (
isinstance(operation, operations.CreateModel) and
operation.name_lower == dependency[1].lower()
)
# Created field
elif dependency[2] is not None and dependency[3] is True:
return (
(
isinstance(operation, operations.CreateModel) and
operation.name_lower == dependency[1].lower() and
any(dependency[2] == x for x, y in operation.fields)
) or
(
isinstance(operation, operations.AddField) and
operation.model_name_lower == dependency[1].lower() and
operation.name_lower == dependency[2].lower()
)
)
# Removed field
elif dependency[2] is not None and dependency[3] is False:
return (
isinstance(operation, operations.RemoveField) and
operation.model_name_lower == dependency[1].lower() and
operation.name_lower == dependency[2].lower()
)
# Removed model
elif dependency[2] is None and dependency[3] is False:
return (
isinstance(operation, operations.DeleteModel) and
operation.name_lower == dependency[1].lower()
)
# Field being altered
elif dependency[2] is not None and dependency[3] == "alter":
return (
isinstance(operation, operations.AlterField) and
operation.model_name_lower == dependency[1].lower() and
operation.name_lower == dependency[2].lower()
)
# order_with_respect_to being unset for a field
elif dependency[2] is not None and dependency[3] == "order_wrt_unset":
return (
isinstance(operation, operations.AlterOrderWithRespectTo) and
operation.name_lower == dependency[1].lower() and
(operation.order_with_respect_to or "").lower() != dependency[2].lower()
)
# Field is removed and part of an index/unique_together
elif dependency[2] is not None and dependency[3] == "foo_together_change":
return (
isinstance(operation, (operations.AlterUniqueTogether,
operations.AlterIndexTogether)) and
operation.name_lower == dependency[1].lower()
)
# Unknown dependency. Raise an error.
else:
raise ValueError("Can't handle dependency %r" % (dependency,))
def add_operation(self, app_label, operation, dependencies=None, beginning=False):
# Dependencies are (app_label, model_name, field_name, create/delete as True/False)
operation._auto_deps = dependencies or []
if beginning:
self.generated_operations.setdefault(app_label, []).insert(0, operation)
else:
self.generated_operations.setdefault(app_label, []).append(operation)
def swappable_first_key(self, item):
"""
Place potential swappable models first in lists of created models (only
real way to solve #22783).
"""
try:
model_state = self.to_state.models[item]
base_names = {
base if isinstance(base, str) else base.__name__
for base in model_state.bases
}
string_version = "%s.%s" % (item[0], item[1])
if (
model_state.options.get('swappable') or
"AbstractUser" in base_names or
"AbstractBaseUser" in base_names or
settings.AUTH_USER_MODEL.lower() == string_version.lower()
):
return ("___" + item[0], "___" + item[1])
except LookupError:
pass
return item
def generate_renamed_models(self):
"""
Find any renamed models, generate the operations for them, and remove
the old entry from the model lists. Must be run before other
model-level generation.
"""
self.renamed_models = {}
self.renamed_models_rel = {}
added_models = self.new_model_keys - self.old_model_keys
for app_label, model_name in sorted(added_models):
model_state = self.to_state.models[app_label, model_name]
model_fields_def = self.only_relation_agnostic_fields(model_state.fields)
removed_models = self.old_model_keys - self.new_model_keys
for rem_app_label, rem_model_name in removed_models:
if rem_app_label == app_label:
rem_model_state = self.from_state.models[rem_app_label, rem_model_name]
rem_model_fields_def = self.only_relation_agnostic_fields(rem_model_state.fields)
if model_fields_def == rem_model_fields_def:
if self.questioner.ask_rename_model(rem_model_state, model_state):
dependencies = []
fields = list(model_state.fields.values()) + [
field.remote_field
for relations in self.to_state.relations[app_label, model_name].values()
for field in relations.values()
]
for field in fields:
if field.is_relation:
dependencies.extend(
self._get_dependencies_for_foreign_key(
app_label, model_name, field, self.to_state,
)
)
self.add_operation(
app_label,
operations.RenameModel(
old_name=rem_model_state.name,
new_name=model_state.name,
),
dependencies=dependencies,
)
self.renamed_models[app_label, model_name] = rem_model_name
renamed_models_rel_key = '%s.%s' % (
rem_model_state.app_label,
rem_model_state.name_lower,
)
self.renamed_models_rel[renamed_models_rel_key] = '%s.%s' % (
model_state.app_label,
model_state.name_lower,
)
self.old_model_keys.remove((rem_app_label, rem_model_name))
self.old_model_keys.add((app_label, model_name))
break
def generate_created_models(self):
"""
Find all new models (both managed and unmanaged) and make create
operations for them as well as separate operations to create any
foreign key or M2M relationships (these are optimized later, if
possible).
Defer any model options that refer to collections of fields that might
be deferred (e.g. unique_together, index_together).
"""
old_keys = self.old_model_keys | self.old_unmanaged_keys
added_models = self.new_model_keys - old_keys
added_unmanaged_models = self.new_unmanaged_keys - old_keys
all_added_models = chain(
sorted(added_models, key=self.swappable_first_key, reverse=True),
sorted(added_unmanaged_models, key=self.swappable_first_key, reverse=True)
)
for app_label, model_name in all_added_models:
model_state = self.to_state.models[app_label, model_name]
# Gather related fields
related_fields = {}
primary_key_rel = None
for field_name, field in model_state.fields.items():
if field.remote_field:
if field.remote_field.model:
if field.primary_key:
primary_key_rel = field.remote_field.model
elif not field.remote_field.parent_link:
related_fields[field_name] = field
if getattr(field.remote_field, 'through', None):
related_fields[field_name] = field
# Are there indexes/unique|index_together to defer?
indexes = model_state.options.pop('indexes')
constraints = model_state.options.pop('constraints')
unique_together = model_state.options.pop('unique_together', None)
index_together = model_state.options.pop('index_together', None)
order_with_respect_to = model_state.options.pop('order_with_respect_to', None)
# Depend on the deletion of any possible proxy version of us
dependencies = [
(app_label, model_name, None, False),
]
# Depend on all bases
for base in model_state.bases:
if isinstance(base, str) and "." in base:
base_app_label, base_name = base.split(".", 1)
dependencies.append((base_app_label, base_name, None, True))
# Depend on the removal of base fields if the new model has
# a field with the same name.
old_base_model_state = self.from_state.models.get((base_app_label, base_name))
new_base_model_state = self.to_state.models.get((base_app_label, base_name))
if old_base_model_state and new_base_model_state:
removed_base_fields = set(old_base_model_state.fields).difference(
new_base_model_state.fields,
).intersection(model_state.fields)
for removed_base_field in removed_base_fields:
dependencies.append((base_app_label, base_name, removed_base_field, False))
# Depend on the other end of the primary key if it's a relation
if primary_key_rel:
dependencies.append(
resolve_relation(
primary_key_rel, app_label, model_name,
) + (None, True)
)
# Generate creation operation
self.add_operation(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[d for d in model_state.fields.items() if d[0] not in related_fields],
options=model_state.options,
bases=model_state.bases,
managers=model_state.managers,
),
dependencies=dependencies,
beginning=True,
)
# Don't add operations which modify the database for unmanaged models
if not model_state.options.get('managed', True):
continue
# Generate operations for each related field
for name, field in sorted(related_fields.items()):
dependencies = self._get_dependencies_for_foreign_key(
app_label, model_name, field, self.to_state,
)
# Depend on our own model being created
dependencies.append((app_label, model_name, None, True))
# Make operation
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=name,
field=field,
),
dependencies=list(set(dependencies)),
)
# Generate other opns
if order_with_respect_to:
self.add_operation(
app_label,
operations.AlterOrderWithRespectTo(
name=model_name,
order_with_respect_to=order_with_respect_to,
),
dependencies=[
(app_label, model_name, order_with_respect_to, True),
(app_label, model_name, None, True),
]
)
related_dependencies = [
(app_label, model_name, name, True)
for name in sorted(related_fields)
]
related_dependencies.append((app_label, model_name, None, True))
for index in indexes:
self.add_operation(
app_label,
operations.AddIndex(
model_name=model_name,
index=index,
),
dependencies=related_dependencies,
)
for constraint in constraints:
self.add_operation(
app_label,
operations.AddConstraint(
model_name=model_name,
constraint=constraint,
),
dependencies=related_dependencies,
)
if unique_together:
self.add_operation(
app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=unique_together,
),
dependencies=related_dependencies
)
if index_together:
self.add_operation(
app_label,
operations.AlterIndexTogether(
name=model_name,
index_together=index_together,
),
dependencies=related_dependencies
)
# Fix relationships if the model changed from a proxy model to a
# concrete model.
relations = self.to_state.relations
if (app_label, model_name) in self.old_proxy_keys:
for related_model_key, related_fields in relations[app_label, model_name].items():
related_model_state = self.to_state.models[related_model_key]
for related_field_name, related_field in related_fields.items():
self.add_operation(
related_model_state.app_label,
operations.AlterField(
model_name=related_model_state.name,
name=related_field_name,
field=related_field,
),
dependencies=[(app_label, model_name, None, True)],
)
def generate_created_proxies(self):
"""
Make CreateModel statements for proxy models. Use the same statements
as that way there's less code duplication, but for proxy models it's
safe to skip all the pointless field stuff and chuck out an operation.
"""
added = self.new_proxy_keys - self.old_proxy_keys
for app_label, model_name in sorted(added):
model_state = self.to_state.models[app_label, model_name]
assert model_state.options.get("proxy")
# Depend on the deletion of any possible non-proxy version of us
dependencies = [
(app_label, model_name, None, False),
]
# Depend on all bases
for base in model_state.bases:
if isinstance(base, str) and "." in base:
base_app_label, base_name = base.split(".", 1)
dependencies.append((base_app_label, base_name, None, True))
# Generate creation operation
self.add_operation(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[],
options=model_state.options,
bases=model_state.bases,
managers=model_state.managers,
),
# Depend on the deletion of any possible non-proxy version of us
dependencies=dependencies,
)
def generate_deleted_models(self):
"""
Find all deleted models (managed and unmanaged) and make delete
operations for them as well as separate operations to delete any
foreign key or M2M relationships (these are optimized later, if
possible).
Also bring forward removal of any model options that refer to
collections of fields - the inverse of generate_created_models().
"""
new_keys = self.new_model_keys | self.new_unmanaged_keys
deleted_models = self.old_model_keys - new_keys
deleted_unmanaged_models = self.old_unmanaged_keys - new_keys
all_deleted_models = chain(sorted(deleted_models), sorted(deleted_unmanaged_models))
for app_label, model_name in all_deleted_models:
model_state = self.from_state.models[app_label, model_name]
# Gather related fields
related_fields = {}
for field_name, field in model_state.fields.items():
if field.remote_field:
if field.remote_field.model:
related_fields[field_name] = field
if getattr(field.remote_field, 'through', None):
related_fields[field_name] = field
# Generate option removal first
unique_together = model_state.options.pop('unique_together', None)
index_together = model_state.options.pop('index_together', None)
if unique_together:
self.add_operation(
app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=None,
)
)
if index_together:
self.add_operation(
app_label,
operations.AlterIndexTogether(
name=model_name,
index_together=None,
)
)
# Then remove each related field
for name in sorted(related_fields):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=name,
)
)
# Finally, remove the model.
# This depends on both the removal/alteration of all incoming fields
# and the removal of all its own related fields, and if it's
# a through model the field that references it.
dependencies = []
relations = self.from_state.relations
for (related_object_app_label, object_name), relation_related_fields in (
relations[app_label, model_name].items()
):
for field_name, field in relation_related_fields.items():
dependencies.append(
(related_object_app_label, object_name, field_name, False),
)
if not field.many_to_many:
dependencies.append(
(related_object_app_label, object_name, field_name, 'alter'),
)
for name in sorted(related_fields):
dependencies.append((app_label, model_name, name, False))
# We're referenced in another field's through=
through_user = self.through_users.get((app_label, model_state.name_lower))
if through_user:
dependencies.append((through_user[0], through_user[1], through_user[2], False))
# Finally, make the operation, deduping any dependencies
self.add_operation(
app_label,
operations.DeleteModel(
name=model_state.name,
),
dependencies=list(set(dependencies)),
)
def generate_deleted_proxies(self):
"""Make DeleteModel options for proxy models."""
deleted = self.old_proxy_keys - self.new_proxy_keys
for app_label, model_name in sorted(deleted):
model_state = self.from_state.models[app_label, model_name]
assert model_state.options.get("proxy")
self.add_operation(
app_label,
operations.DeleteModel(
name=model_state.name,
),
)
def generate_renamed_fields(self):
"""Work out renamed fields."""
self.renamed_fields = {}
for app_label, model_name, field_name in sorted(self.new_field_keys - self.old_field_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, old_model_name]
field = new_model_state.get_field(field_name)
# Scan to see if this is actually a rename!
field_dec = self.deep_deconstruct(field)
for rem_app_label, rem_model_name, rem_field_name in sorted(self.old_field_keys - self.new_field_keys):
if rem_app_label == app_label and rem_model_name == model_name:
old_field = old_model_state.get_field(rem_field_name)
old_field_dec = self.deep_deconstruct(old_field)
if field.remote_field and field.remote_field.model and 'to' in old_field_dec[2]:
old_rel_to = old_field_dec[2]['to']
if old_rel_to in self.renamed_models_rel:
old_field_dec[2]['to'] = self.renamed_models_rel[old_rel_to]
old_field.set_attributes_from_name(rem_field_name)
old_db_column = old_field.get_attname_column()[1]
if (old_field_dec == field_dec or (
# Was the field renamed and db_column equal to the
# old field's column added?
old_field_dec[0:2] == field_dec[0:2] and
dict(old_field_dec[2], db_column=old_db_column) == field_dec[2])):
if self.questioner.ask_rename(model_name, rem_field_name, field_name, field):
# A db_column mismatch requires a prior noop
# AlterField for the subsequent RenameField to be a
# noop on attempts at preserving the old name.
if old_field.db_column != field.db_column:
altered_field = field.clone()
altered_field.name = rem_field_name
self.add_operation(
app_label,
operations.AlterField(
model_name=model_name,
name=rem_field_name,
field=altered_field,
),
)
self.add_operation(
app_label,
operations.RenameField(
model_name=model_name,
old_name=rem_field_name,
new_name=field_name,
)
)
self.old_field_keys.remove((rem_app_label, rem_model_name, rem_field_name))
self.old_field_keys.add((app_label, model_name, field_name))
self.renamed_fields[app_label, model_name, field_name] = rem_field_name
break
def generate_added_fields(self):
"""Make AddField operations."""
for app_label, model_name, field_name in sorted(self.new_field_keys - self.old_field_keys):
self._generate_added_field(app_label, model_name, field_name)
def _generate_added_field(self, app_label, model_name, field_name):
field = self.to_state.models[app_label, model_name].get_field(field_name)
# Fields that are foreignkeys/m2ms depend on stuff
dependencies = []
if field.remote_field and field.remote_field.model:
dependencies.extend(self._get_dependencies_for_foreign_key(
app_label, model_name, field, self.to_state,
))
# You can't just add NOT NULL fields with no default or fields
# which don't allow empty strings as default.
time_fields = (models.DateField, models.DateTimeField, models.TimeField)
preserve_default = (
field.null or field.has_default() or field.many_to_many or
(field.blank and field.empty_strings_allowed) or
(isinstance(field, time_fields) and field.auto_now)
)
if not preserve_default:
field = field.clone()
if isinstance(field, time_fields) and field.auto_now_add:
field.default = self.questioner.ask_auto_now_add_addition(field_name, model_name)
else:
field.default = self.questioner.ask_not_null_addition(field_name, model_name)
if (
field.unique and
field.default is not models.NOT_PROVIDED and
callable(field.default)
):
self.questioner.ask_unique_callable_default_addition(field_name, model_name)
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
),
dependencies=dependencies,
)
def generate_removed_fields(self):
"""Make RemoveField operations."""
for app_label, model_name, field_name in sorted(self.old_field_keys - self.new_field_keys):
self._generate_removed_field(app_label, model_name, field_name)
def _generate_removed_field(self, app_label, model_name, field_name):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=field_name,
),
# We might need to depend on the removal of an
# order_with_respect_to or index/unique_together operation;
# this is safely ignored if there isn't one
dependencies=[
(app_label, model_name, field_name, "order_wrt_unset"),
(app_label, model_name, field_name, "foo_together_change"),
],
)
def generate_altered_fields(self):
"""
Make AlterField operations, or possibly RemovedField/AddField if alter
isn't possible.
"""
for app_label, model_name, field_name in sorted(self.old_field_keys & self.new_field_keys):
# Did the field change?
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_field_name = self.renamed_fields.get((app_label, model_name, field_name), field_name)
old_field = self.from_state.models[app_label, old_model_name].get_field(old_field_name)
new_field = self.to_state.models[app_label, model_name].get_field(field_name)
dependencies = []
# Implement any model renames on relations; these are handled by RenameModel
# so we need to exclude them from the comparison
if hasattr(new_field, "remote_field") and getattr(new_field.remote_field, "model", None):
rename_key = resolve_relation(new_field.remote_field.model, app_label, model_name)
if rename_key in self.renamed_models:
new_field.remote_field.model = old_field.remote_field.model
# Handle ForeignKey which can only have a single to_field.
remote_field_name = getattr(new_field.remote_field, 'field_name', None)
if remote_field_name:
to_field_rename_key = rename_key + (remote_field_name,)
if to_field_rename_key in self.renamed_fields:
# Repoint both model and field name because to_field
# inclusion in ForeignKey.deconstruct() is based on
# both.
new_field.remote_field.model = old_field.remote_field.model
new_field.remote_field.field_name = old_field.remote_field.field_name
# Handle ForeignObjects which can have multiple from_fields/to_fields.
from_fields = getattr(new_field, 'from_fields', None)
if from_fields:
from_rename_key = (app_label, model_name)
new_field.from_fields = tuple([
self.renamed_fields.get(from_rename_key + (from_field,), from_field)
for from_field in from_fields
])
new_field.to_fields = tuple([
self.renamed_fields.get(rename_key + (to_field,), to_field)
for to_field in new_field.to_fields
])
dependencies.extend(self._get_dependencies_for_foreign_key(
app_label, model_name, new_field, self.to_state,
))
if (
hasattr(new_field, 'remote_field') and
getattr(new_field.remote_field, 'through', None)
):
rename_key = resolve_relation(new_field.remote_field.through, app_label, model_name)
if rename_key in self.renamed_models:
new_field.remote_field.through = old_field.remote_field.through
old_field_dec = self.deep_deconstruct(old_field)
new_field_dec = self.deep_deconstruct(new_field)
# If the field was confirmed to be renamed it means that only
# db_column was allowed to change which generate_renamed_fields()
# already accounts for by adding an AlterField operation.
if old_field_dec != new_field_dec and old_field_name == field_name:
both_m2m = old_field.many_to_many and new_field.many_to_many
neither_m2m = not old_field.many_to_many and not new_field.many_to_many
if both_m2m or neither_m2m:
# Either both fields are m2m or neither is
preserve_default = True
if (old_field.null and not new_field.null and not new_field.has_default() and
not new_field.many_to_many):
field = new_field.clone()
new_default = self.questioner.ask_not_null_alteration(field_name, model_name)
if new_default is not models.NOT_PROVIDED:
field.default = new_default
preserve_default = False
else:
field = new_field
self.add_operation(
app_label,
operations.AlterField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
),
dependencies=dependencies,
)
else:
# We cannot alter between m2m and concrete fields
self._generate_removed_field(app_label, model_name, field_name)
self._generate_added_field(app_label, model_name, field_name)
def create_altered_indexes(self):
option_name = operations.AddIndex.option_name
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_indexes = old_model_state.options[option_name]
new_indexes = new_model_state.options[option_name]
add_idx = [idx for idx in new_indexes if idx not in old_indexes]
rem_idx = [idx for idx in old_indexes if idx not in new_indexes]
self.altered_indexes.update({
(app_label, model_name): {
'added_indexes': add_idx, 'removed_indexes': rem_idx,
}
})
def generate_added_indexes(self):
for (app_label, model_name), alt_indexes in self.altered_indexes.items():
for index in alt_indexes['added_indexes']:
self.add_operation(
app_label,
operations.AddIndex(
model_name=model_name,
index=index,
)
)
def generate_removed_indexes(self):
for (app_label, model_name), alt_indexes in self.altered_indexes.items():
for index in alt_indexes['removed_indexes']:
self.add_operation(
app_label,
operations.RemoveIndex(
model_name=model_name,
name=index.name,
)
)
def create_altered_constraints(self):
option_name = operations.AddConstraint.option_name
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_constraints = old_model_state.options[option_name]
new_constraints = new_model_state.options[option_name]
add_constraints = [c for c in new_constraints if c not in old_constraints]
rem_constraints = [c for c in old_constraints if c not in new_constraints]
self.altered_constraints.update({
(app_label, model_name): {
'added_constraints': add_constraints, 'removed_constraints': rem_constraints,
}
})
def generate_added_constraints(self):
for (app_label, model_name), alt_constraints in self.altered_constraints.items():
for constraint in alt_constraints['added_constraints']:
self.add_operation(
app_label,
operations.AddConstraint(
model_name=model_name,
constraint=constraint,
)
)
def generate_removed_constraints(self):
for (app_label, model_name), alt_constraints in self.altered_constraints.items():
for constraint in alt_constraints['removed_constraints']:
self.add_operation(
app_label,
operations.RemoveConstraint(
model_name=model_name,
name=constraint.name,
)
)
@staticmethod
def _get_dependencies_for_foreign_key(app_label, model_name, field, project_state):
remote_field_model = None
if hasattr(field.remote_field, 'model'):
remote_field_model = field.remote_field.model
else:
relations = project_state.relations[app_label, model_name]
for (remote_app_label, remote_model_name), fields in relations.items():
if any(
field == related_field.remote_field
for related_field in fields.values()
):
remote_field_model = f'{remote_app_label}.{remote_model_name}'
break
# Account for FKs to swappable models
swappable_setting = getattr(field, 'swappable_setting', None)
if swappable_setting is not None:
dep_app_label = "__setting__"
dep_object_name = swappable_setting
else:
dep_app_label, dep_object_name = resolve_relation(
remote_field_model, app_label, model_name,
)
dependencies = [(dep_app_label, dep_object_name, None, True)]
if getattr(field.remote_field, 'through', None):
through_app_label, through_object_name = resolve_relation(
remote_field_model, app_label, model_name,
)
dependencies.append((through_app_label, through_object_name, None, True))
return dependencies
def _get_altered_foo_together_operations(self, option_name):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
# We run the old version through the field renames to account for those
old_value = old_model_state.options.get(option_name)
old_value = {
tuple(
self.renamed_fields.get((app_label, model_name, n), n)
for n in unique
)
for unique in old_value
} if old_value else set()
new_value = new_model_state.options.get(option_name)
new_value = set(new_value) if new_value else set()
if old_value != new_value:
dependencies = []
for foo_togethers in new_value:
for field_name in foo_togethers:
field = new_model_state.get_field(field_name)
if field.remote_field and field.remote_field.model:
dependencies.extend(self._get_dependencies_for_foreign_key(
app_label, model_name, field, self.to_state,
))
yield (
old_value,
new_value,
app_label,
model_name,
dependencies,
)
def _generate_removed_altered_foo_together(self, operation):
for (
old_value,
new_value,
app_label,
model_name,
dependencies,
) in self._get_altered_foo_together_operations(operation.option_name):
removal_value = new_value.intersection(old_value)
if removal_value or old_value:
self.add_operation(
app_label,
operation(name=model_name, **{operation.option_name: removal_value}),
dependencies=dependencies,
)
def generate_removed_altered_unique_together(self):
self._generate_removed_altered_foo_together(operations.AlterUniqueTogether)
def generate_removed_altered_index_together(self):
self._generate_removed_altered_foo_together(operations.AlterIndexTogether)
def _generate_altered_foo_together(self, operation):
for (
old_value,
new_value,
app_label,
model_name,
dependencies,
) in self._get_altered_foo_together_operations(operation.option_name):
removal_value = new_value.intersection(old_value)
if new_value != removal_value:
self.add_operation(
app_label,
operation(name=model_name, **{operation.option_name: new_value}),
dependencies=dependencies,
)
def generate_altered_unique_together(self):
self._generate_altered_foo_together(operations.AlterUniqueTogether)
def generate_altered_index_together(self):
self._generate_altered_foo_together(operations.AlterIndexTogether)
def generate_altered_db_table(self):
models_to_check = self.kept_model_keys.union(self.kept_proxy_keys, self.kept_unmanaged_keys)
for app_label, model_name in sorted(models_to_check):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_db_table_name = old_model_state.options.get('db_table')
new_db_table_name = new_model_state.options.get('db_table')
if old_db_table_name != new_db_table_name:
self.add_operation(
app_label,
operations.AlterModelTable(
name=model_name,
table=new_db_table_name,
)
)
def generate_altered_options(self):
"""
Work out if any non-schema-affecting options have changed and make an
operation to represent them in state changes (in case Python code in
migrations needs them).
"""
models_to_check = self.kept_model_keys.union(
self.kept_proxy_keys,
self.kept_unmanaged_keys,
# unmanaged converted to managed
self.old_unmanaged_keys & self.new_model_keys,
# managed converted to unmanaged
self.old_model_keys & self.new_unmanaged_keys,
)
for app_label, model_name in sorted(models_to_check):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_options = {
key: value for key, value in old_model_state.options.items()
if key in AlterModelOptions.ALTER_OPTION_KEYS
}
new_options = {
key: value for key, value in new_model_state.options.items()
if key in AlterModelOptions.ALTER_OPTION_KEYS
}
if old_options != new_options:
self.add_operation(
app_label,
operations.AlterModelOptions(
name=model_name,
options=new_options,
)
)
def generate_altered_order_with_respect_to(self):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
if (old_model_state.options.get("order_with_respect_to") !=
new_model_state.options.get("order_with_respect_to")):
# Make sure it comes second if we're adding
# (removal dependency is part of RemoveField)
dependencies = []
if new_model_state.options.get("order_with_respect_to"):
dependencies.append((
app_label,
model_name,
new_model_state.options["order_with_respect_to"],
True,
))
# Actually generate the operation
self.add_operation(
app_label,
operations.AlterOrderWithRespectTo(
name=model_name,
order_with_respect_to=new_model_state.options.get('order_with_respect_to'),
),
dependencies=dependencies,
)
def generate_altered_managers(self):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
if old_model_state.managers != new_model_state.managers:
self.add_operation(
app_label,
operations.AlterModelManagers(
name=model_name,
managers=new_model_state.managers,
)
)
def arrange_for_graph(self, changes, graph, migration_name=None):
"""
Take a result from changes() and a MigrationGraph, and fix the names
and dependencies of the changes so they extend the graph from the leaf
nodes for each app.
"""
leaves = graph.leaf_nodes()
name_map = {}
for app_label, migrations in list(changes.items()):
if not migrations:
continue
# Find the app label's current leaf node
app_leaf = None
for leaf in leaves:
if leaf[0] == app_label:
app_leaf = leaf
break
# Do they want an initial migration for this app?
if app_leaf is None and not self.questioner.ask_initial(app_label):
# They don't.
for migration in migrations:
name_map[(app_label, migration.name)] = (app_label, "__first__")
del changes[app_label]
continue
# Work out the next number in the sequence
if app_leaf is None:
next_number = 1
else:
next_number = (self.parse_number(app_leaf[1]) or 0) + 1
# Name each migration
for i, migration in enumerate(migrations):
if i == 0 and app_leaf:
migration.dependencies.append(app_leaf)
new_name_parts = ['%04i' % next_number]
if migration_name:
new_name_parts.append(migration_name)
elif i == 0 and not app_leaf:
new_name_parts.append('initial')
else:
new_name_parts.append(migration.suggest_name()[:100])
new_name = '_'.join(new_name_parts)
name_map[(app_label, migration.name)] = (app_label, new_name)
next_number += 1
migration.name = new_name
# Now fix dependencies
for migrations in changes.values():
for migration in migrations:
migration.dependencies = [name_map.get(d, d) for d in migration.dependencies]
return changes
def _trim_to_apps(self, changes, app_labels):
"""
Take changes from arrange_for_graph() and set of app labels, and return
a modified set of changes which trims out as many migrations that are
not in app_labels as possible. Note that some other migrations may
still be present as they may be required dependencies.
"""
# Gather other app dependencies in a first pass
app_dependencies = {}
for app_label, migrations in changes.items():
for migration in migrations:
for dep_app_label, name in migration.dependencies:
app_dependencies.setdefault(app_label, set()).add(dep_app_label)
required_apps = set(app_labels)
# Keep resolving till there's no change
old_required_apps = None
while old_required_apps != required_apps:
old_required_apps = set(required_apps)
required_apps.update(*[app_dependencies.get(app_label, ()) for app_label in required_apps])
# Remove all migrations that aren't needed
for app_label in list(changes):
if app_label not in required_apps:
del changes[app_label]
return changes
@classmethod
def parse_number(cls, name):
"""
Given a migration name, try to extract a number from the beginning of
it. For a squashed migration such as '0001_squashed_0004…', return the
second number. If no number is found, return None.
"""
if squashed_match := re.search(r'.*_squashed_(\d+)', name):
return int(squashed_match[1])
match = re.match(r'^\d+', name)
if match:
return int(match[0])
return None
|
eddef60894636ce41464d8e3440d197857a9b5fff114fa3134341593ff7f54a2 | import builtins
import collections.abc
import datetime
import decimal
import enum
import functools
import math
import os
import pathlib
import re
import types
import uuid
from django.conf import SettingsReference
from django.db import models
from django.db.migrations.operations.base import Operation
from django.db.migrations.utils import COMPILED_REGEX_TYPE, RegexObject
from django.utils.functional import LazyObject, Promise
from django.utils.timezone import utc
from django.utils.version import get_docs_version
class BaseSerializer:
def __init__(self, value):
self.value = value
def serialize(self):
raise NotImplementedError('Subclasses of BaseSerializer must implement the serialize() method.')
class BaseSequenceSerializer(BaseSerializer):
def _format(self):
raise NotImplementedError('Subclasses of BaseSequenceSerializer must implement the _format() method.')
def serialize(self):
imports = set()
strings = []
for item in self.value:
item_string, item_imports = serializer_factory(item).serialize()
imports.update(item_imports)
strings.append(item_string)
value = self._format()
return value % (", ".join(strings)), imports
class BaseSimpleSerializer(BaseSerializer):
def serialize(self):
return repr(self.value), set()
class ChoicesSerializer(BaseSerializer):
def serialize(self):
return serializer_factory(self.value.value).serialize()
class DateTimeSerializer(BaseSerializer):
"""For datetime.*, except datetime.datetime."""
def serialize(self):
return repr(self.value), {'import datetime'}
class DatetimeDatetimeSerializer(BaseSerializer):
"""For datetime.datetime."""
def serialize(self):
if self.value.tzinfo is not None and self.value.tzinfo != utc:
self.value = self.value.astimezone(utc)
imports = ["import datetime"]
if self.value.tzinfo is not None:
imports.append("from django.utils.timezone import utc")
return repr(self.value).replace('datetime.timezone.utc', 'utc'), set(imports)
class DecimalSerializer(BaseSerializer):
def serialize(self):
return repr(self.value), {"from decimal import Decimal"}
class DeconstructableSerializer(BaseSerializer):
@staticmethod
def serialize_deconstructed(path, args, kwargs):
name, imports = DeconstructableSerializer._serialize_path(path)
strings = []
for arg in args:
arg_string, arg_imports = serializer_factory(arg).serialize()
strings.append(arg_string)
imports.update(arg_imports)
for kw, arg in sorted(kwargs.items()):
arg_string, arg_imports = serializer_factory(arg).serialize()
imports.update(arg_imports)
strings.append("%s=%s" % (kw, arg_string))
return "%s(%s)" % (name, ", ".join(strings)), imports
@staticmethod
def _serialize_path(path):
module, name = path.rsplit(".", 1)
if module == "django.db.models":
imports = {"from django.db import models"}
name = "models.%s" % name
else:
imports = {"import %s" % module}
name = path
return name, imports
def serialize(self):
return self.serialize_deconstructed(*self.value.deconstruct())
class DictionarySerializer(BaseSerializer):
def serialize(self):
imports = set()
strings = []
for k, v in sorted(self.value.items()):
k_string, k_imports = serializer_factory(k).serialize()
v_string, v_imports = serializer_factory(v).serialize()
imports.update(k_imports)
imports.update(v_imports)
strings.append((k_string, v_string))
return "{%s}" % (", ".join("%s: %s" % (k, v) for k, v in strings)), imports
class EnumSerializer(BaseSerializer):
def serialize(self):
enum_class = self.value.__class__
module = enum_class.__module__
return (
'%s.%s[%r]' % (module, enum_class.__qualname__, self.value.name),
{'import %s' % module},
)
class FloatSerializer(BaseSimpleSerializer):
def serialize(self):
if math.isnan(self.value) or math.isinf(self.value):
return 'float("{}")'.format(self.value), set()
return super().serialize()
class FrozensetSerializer(BaseSequenceSerializer):
def _format(self):
return "frozenset([%s])"
class FunctionTypeSerializer(BaseSerializer):
def serialize(self):
if getattr(self.value, "__self__", None) and isinstance(self.value.__self__, type):
klass = self.value.__self__
module = klass.__module__
return "%s.%s.%s" % (module, klass.__name__, self.value.__name__), {"import %s" % module}
# Further error checking
if self.value.__name__ == '<lambda>':
raise ValueError("Cannot serialize function: lambda")
if self.value.__module__ is None:
raise ValueError("Cannot serialize function %r: No module" % self.value)
module_name = self.value.__module__
if '<' not in self.value.__qualname__: # Qualname can include <locals>
return '%s.%s' % (module_name, self.value.__qualname__), {'import %s' % self.value.__module__}
raise ValueError(
'Could not find function %s in %s.\n' % (self.value.__name__, module_name)
)
class FunctoolsPartialSerializer(BaseSerializer):
def serialize(self):
# Serialize functools.partial() arguments
func_string, func_imports = serializer_factory(self.value.func).serialize()
args_string, args_imports = serializer_factory(self.value.args).serialize()
keywords_string, keywords_imports = serializer_factory(self.value.keywords).serialize()
# Add any imports needed by arguments
imports = {'import functools', *func_imports, *args_imports, *keywords_imports}
return (
'functools.%s(%s, *%s, **%s)' % (
self.value.__class__.__name__,
func_string,
args_string,
keywords_string,
),
imports,
)
class IterableSerializer(BaseSerializer):
def serialize(self):
imports = set()
strings = []
for item in self.value:
item_string, item_imports = serializer_factory(item).serialize()
imports.update(item_imports)
strings.append(item_string)
# When len(strings)==0, the empty iterable should be serialized as
# "()", not "(,)" because (,) is invalid Python syntax.
value = "(%s)" if len(strings) != 1 else "(%s,)"
return value % (", ".join(strings)), imports
class ModelFieldSerializer(DeconstructableSerializer):
def serialize(self):
attr_name, path, args, kwargs = self.value.deconstruct()
return self.serialize_deconstructed(path, args, kwargs)
class ModelManagerSerializer(DeconstructableSerializer):
def serialize(self):
as_manager, manager_path, qs_path, args, kwargs = self.value.deconstruct()
if as_manager:
name, imports = self._serialize_path(qs_path)
return "%s.as_manager()" % name, imports
else:
return self.serialize_deconstructed(manager_path, args, kwargs)
class OperationSerializer(BaseSerializer):
def serialize(self):
from django.db.migrations.writer import OperationWriter
string, imports = OperationWriter(self.value, indentation=0).serialize()
# Nested operation, trailing comma is handled in upper OperationWriter._write()
return string.rstrip(','), imports
class PathLikeSerializer(BaseSerializer):
def serialize(self):
return repr(os.fspath(self.value)), {}
class PathSerializer(BaseSerializer):
def serialize(self):
# Convert concrete paths to pure paths to avoid issues with migrations
# generated on one platform being used on a different platform.
prefix = 'Pure' if isinstance(self.value, pathlib.Path) else ''
return 'pathlib.%s%r' % (prefix, self.value), {'import pathlib'}
class RegexSerializer(BaseSerializer):
def serialize(self):
regex_pattern, pattern_imports = serializer_factory(self.value.pattern).serialize()
# Turn off default implicit flags (e.g. re.U) because regexes with the
# same implicit and explicit flags aren't equal.
flags = self.value.flags ^ re.compile('').flags
regex_flags, flag_imports = serializer_factory(flags).serialize()
imports = {'import re', *pattern_imports, *flag_imports}
args = [regex_pattern]
if flags:
args.append(regex_flags)
return "re.compile(%s)" % ', '.join(args), imports
class SequenceSerializer(BaseSequenceSerializer):
def _format(self):
return "[%s]"
class SetSerializer(BaseSequenceSerializer):
def _format(self):
# Serialize as a set literal except when value is empty because {}
# is an empty dict.
return '{%s}' if self.value else 'set(%s)'
class SettingsReferenceSerializer(BaseSerializer):
def serialize(self):
return "settings.%s" % self.value.setting_name, {"from django.conf import settings"}
class TupleSerializer(BaseSequenceSerializer):
def _format(self):
# When len(value)==0, the empty tuple should be serialized as "()",
# not "(,)" because (,) is invalid Python syntax.
return "(%s)" if len(self.value) != 1 else "(%s,)"
class TypeSerializer(BaseSerializer):
def serialize(self):
special_cases = [
(models.Model, "models.Model", ['from django.db import models']),
(type(None), 'type(None)', []),
]
for case, string, imports in special_cases:
if case is self.value:
return string, set(imports)
if hasattr(self.value, "__module__"):
module = self.value.__module__
if module == builtins.__name__:
return self.value.__name__, set()
else:
return "%s.%s" % (module, self.value.__qualname__), {"import %s" % module}
class UUIDSerializer(BaseSerializer):
def serialize(self):
return "uuid.%s" % repr(self.value), {"import uuid"}
class Serializer:
_registry = {
# Some of these are order-dependent.
frozenset: FrozensetSerializer,
list: SequenceSerializer,
set: SetSerializer,
tuple: TupleSerializer,
dict: DictionarySerializer,
models.Choices: ChoicesSerializer,
enum.Enum: EnumSerializer,
datetime.datetime: DatetimeDatetimeSerializer,
(datetime.date, datetime.timedelta, datetime.time): DateTimeSerializer,
SettingsReference: SettingsReferenceSerializer,
float: FloatSerializer,
(bool, int, type(None), bytes, str, range): BaseSimpleSerializer,
decimal.Decimal: DecimalSerializer,
(functools.partial, functools.partialmethod): FunctoolsPartialSerializer,
(types.FunctionType, types.BuiltinFunctionType, types.MethodType): FunctionTypeSerializer,
collections.abc.Iterable: IterableSerializer,
(COMPILED_REGEX_TYPE, RegexObject): RegexSerializer,
uuid.UUID: UUIDSerializer,
pathlib.PurePath: PathSerializer,
os.PathLike: PathLikeSerializer,
}
@classmethod
def register(cls, type_, serializer):
if not issubclass(serializer, BaseSerializer):
raise ValueError("'%s' must inherit from 'BaseSerializer'." % serializer.__name__)
cls._registry[type_] = serializer
@classmethod
def unregister(cls, type_):
cls._registry.pop(type_)
def serializer_factory(value):
if isinstance(value, Promise):
value = str(value)
elif isinstance(value, LazyObject):
# The unwrapped value is returned as the first item of the arguments
# tuple.
value = value.__reduce__()[1][0]
if isinstance(value, models.Field):
return ModelFieldSerializer(value)
if isinstance(value, models.manager.BaseManager):
return ModelManagerSerializer(value)
if isinstance(value, Operation):
return OperationSerializer(value)
if isinstance(value, type):
return TypeSerializer(value)
# Anything that knows how to deconstruct itself.
if hasattr(value, 'deconstruct'):
return DeconstructableSerializer(value)
for type_, serializer_cls in Serializer._registry.items():
if isinstance(value, type_):
return serializer_cls(value)
raise ValueError(
"Cannot serialize: %r\nThere are some values Django cannot serialize into "
"migration files.\nFor more, see https://docs.djangoproject.com/en/%s/"
"topics/migrations/#migration-serializing" % (value, get_docs_version())
)
|
583b39b3766441140194b0c7e8674f0b9730ecd36df74a11ce64c2d23303f394 | """
Classes to represent the definitions of aggregate functions.
"""
from django.core.exceptions import FieldError
from django.db.models.expressions import Case, Func, Star, When
from django.db.models.fields import IntegerField
from django.db.models.functions.comparison import Coalesce
from django.db.models.functions.mixins import (
FixDurationInputMixin, NumericOutputFieldMixin,
)
__all__ = [
'Aggregate', 'Avg', 'Count', 'Max', 'Min', 'StdDev', 'Sum', 'Variance',
]
class Aggregate(Func):
template = '%(function)s(%(distinct)s%(expressions)s)'
contains_aggregate = True
name = None
filter_template = '%s FILTER (WHERE %%(filter)s)'
window_compatible = True
allow_distinct = False
empty_result_set_value = None
def __init__(self, *expressions, distinct=False, filter=None, default=None, **extra):
if distinct and not self.allow_distinct:
raise TypeError("%s does not allow distinct." % self.__class__.__name__)
if default is not None and self.empty_result_set_value is not None:
raise TypeError(f'{self.__class__.__name__} does not allow default.')
self.distinct = distinct
self.filter = filter
self.default = default
super().__init__(*expressions, **extra)
def get_source_fields(self):
# Don't return the filter expression since it's not a source field.
return [e._output_field_or_none for e in super().get_source_expressions()]
def get_source_expressions(self):
source_expressions = super().get_source_expressions()
if self.filter:
return source_expressions + [self.filter]
return source_expressions
def set_source_expressions(self, exprs):
self.filter = self.filter and exprs.pop()
return super().set_source_expressions(exprs)
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
# Aggregates are not allowed in UPDATE queries, so ignore for_save
c = super().resolve_expression(query, allow_joins, reuse, summarize)
c.filter = c.filter and c.filter.resolve_expression(query, allow_joins, reuse, summarize)
if not summarize:
# Call Aggregate.get_source_expressions() to avoid
# returning self.filter and including that in this loop.
expressions = super(Aggregate, c).get_source_expressions()
for index, expr in enumerate(expressions):
if expr.contains_aggregate:
before_resolved = self.get_source_expressions()[index]
name = before_resolved.name if hasattr(before_resolved, 'name') else repr(before_resolved)
raise FieldError("Cannot compute %s('%s'): '%s' is an aggregate" % (c.name, name, name))
if (default := c.default) is None:
return c
if hasattr(default, 'resolve_expression'):
default = default.resolve_expression(query, allow_joins, reuse, summarize)
c.default = None # Reset the default argument before wrapping.
return Coalesce(c, default, output_field=c._output_field_or_none)
@property
def default_alias(self):
expressions = self.get_source_expressions()
if len(expressions) == 1 and hasattr(expressions[0], 'name'):
return '%s__%s' % (expressions[0].name, self.name.lower())
raise TypeError("Complex expressions require an alias")
def get_group_by_cols(self, alias=None):
return []
def as_sql(self, compiler, connection, **extra_context):
extra_context['distinct'] = 'DISTINCT ' if self.distinct else ''
if self.filter:
if connection.features.supports_aggregate_filter_clause:
filter_sql, filter_params = self.filter.as_sql(compiler, connection)
template = self.filter_template % extra_context.get('template', self.template)
sql, params = super().as_sql(
compiler, connection, template=template, filter=filter_sql,
**extra_context
)
return sql, (*params, *filter_params)
else:
copy = self.copy()
copy.filter = None
source_expressions = copy.get_source_expressions()
condition = When(self.filter, then=source_expressions[0])
copy.set_source_expressions([Case(condition)] + source_expressions[1:])
return super(Aggregate, copy).as_sql(compiler, connection, **extra_context)
return super().as_sql(compiler, connection, **extra_context)
def _get_repr_options(self):
options = super()._get_repr_options()
if self.distinct:
options['distinct'] = self.distinct
if self.filter:
options['filter'] = self.filter
return options
class Avg(FixDurationInputMixin, NumericOutputFieldMixin, Aggregate):
function = 'AVG'
name = 'Avg'
allow_distinct = True
class Count(Aggregate):
function = 'COUNT'
name = 'Count'
output_field = IntegerField()
allow_distinct = True
empty_result_set_value = 0
def __init__(self, expression, filter=None, **extra):
if expression == '*':
expression = Star()
if isinstance(expression, Star) and filter is not None:
raise ValueError('Star cannot be used with filter. Please specify a field.')
super().__init__(expression, filter=filter, **extra)
class Max(Aggregate):
function = 'MAX'
name = 'Max'
class Min(Aggregate):
function = 'MIN'
name = 'Min'
class StdDev(NumericOutputFieldMixin, Aggregate):
name = 'StdDev'
def __init__(self, expression, sample=False, **extra):
self.function = 'STDDEV_SAMP' if sample else 'STDDEV_POP'
super().__init__(expression, **extra)
def _get_repr_options(self):
return {**super()._get_repr_options(), 'sample': self.function == 'STDDEV_SAMP'}
class Sum(FixDurationInputMixin, Aggregate):
function = 'SUM'
name = 'Sum'
allow_distinct = True
class Variance(NumericOutputFieldMixin, Aggregate):
name = 'Variance'
def __init__(self, expression, sample=False, **extra):
self.function = 'VAR_SAMP' if sample else 'VAR_POP'
super().__init__(expression, **extra)
def _get_repr_options(self):
return {**super()._get_repr_options(), 'sample': self.function == 'VAR_SAMP'}
|
379072da612377509209dbfd83b519d68b7d41ffd822c0b697435d839debba22 | """
The main QuerySet implementation. This provides the public API for the ORM.
"""
import copy
import operator
import warnings
from itertools import chain, islice
import django
from django.conf import settings
from django.core import exceptions
from django.db import (
DJANGO_VERSION_PICKLE_KEY, IntegrityError, NotSupportedError, connections,
router, transaction,
)
from django.db.models import AutoField, DateField, DateTimeField, sql
from django.db.models.constants import LOOKUP_SEP, OnConflict
from django.db.models.deletion import Collector
from django.db.models.expressions import Case, F, Ref, Value, When
from django.db.models.functions import Cast, Trunc
from django.db.models.query_utils import FilteredRelation, Q
from django.db.models.sql.constants import CURSOR, GET_ITERATOR_CHUNK_SIZE
from django.db.models.utils import create_namedtuple_class, resolve_callables
from django.utils import timezone
from django.utils.deprecation import RemovedInDjango50Warning
from django.utils.functional import cached_property, partition
# The maximum number of results to fetch in a get() query.
MAX_GET_RESULTS = 21
# The maximum number of items to display in a QuerySet.__repr__
REPR_OUTPUT_SIZE = 20
class BaseIterable:
def __init__(self, queryset, chunked_fetch=False, chunk_size=GET_ITERATOR_CHUNK_SIZE):
self.queryset = queryset
self.chunked_fetch = chunked_fetch
self.chunk_size = chunk_size
class ModelIterable(BaseIterable):
"""Iterable that yields a model instance for each row."""
def __iter__(self):
queryset = self.queryset
db = queryset.db
compiler = queryset.query.get_compiler(using=db)
# Execute the query. This will also fill compiler.select, klass_info,
# and annotations.
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
select, klass_info, annotation_col_map = (compiler.select, compiler.klass_info,
compiler.annotation_col_map)
model_cls = klass_info['model']
select_fields = klass_info['select_fields']
model_fields_start, model_fields_end = select_fields[0], select_fields[-1] + 1
init_list = [f[0].target.attname
for f in select[model_fields_start:model_fields_end]]
related_populators = get_related_populators(klass_info, select, db)
known_related_objects = [
(field, related_objs, operator.attrgetter(*[
field.attname
if from_field == 'self' else
queryset.model._meta.get_field(from_field).attname
for from_field in field.from_fields
])) for field, related_objs in queryset._known_related_objects.items()
]
for row in compiler.results_iter(results):
obj = model_cls.from_db(db, init_list, row[model_fields_start:model_fields_end])
for rel_populator in related_populators:
rel_populator.populate(row, obj)
if annotation_col_map:
for attr_name, col_pos in annotation_col_map.items():
setattr(obj, attr_name, row[col_pos])
# Add the known related objects to the model.
for field, rel_objs, rel_getter in known_related_objects:
# Avoid overwriting objects loaded by, e.g., select_related().
if field.is_cached(obj):
continue
rel_obj_id = rel_getter(obj)
try:
rel_obj = rel_objs[rel_obj_id]
except KeyError:
pass # May happen in qs1 | qs2 scenarios.
else:
setattr(obj, field.name, rel_obj)
yield obj
class ValuesIterable(BaseIterable):
"""
Iterable returned by QuerySet.values() that yields a dict for each row.
"""
def __iter__(self):
queryset = self.queryset
query = queryset.query
compiler = query.get_compiler(queryset.db)
# extra(select=...) cols are always at the start of the row.
names = [
*query.extra_select,
*query.values_select,
*query.annotation_select,
]
indexes = range(len(names))
for row in compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size):
yield {names[i]: row[i] for i in indexes}
class ValuesListIterable(BaseIterable):
"""
Iterable returned by QuerySet.values_list(flat=False) that yields a tuple
for each row.
"""
def __iter__(self):
queryset = self.queryset
query = queryset.query
compiler = query.get_compiler(queryset.db)
if queryset._fields:
# extra(select=...) cols are always at the start of the row.
names = [
*query.extra_select,
*query.values_select,
*query.annotation_select,
]
fields = [*queryset._fields, *(f for f in query.annotation_select if f not in queryset._fields)]
if fields != names:
# Reorder according to fields.
index_map = {name: idx for idx, name in enumerate(names)}
rowfactory = operator.itemgetter(*[index_map[f] for f in fields])
return map(
rowfactory,
compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
)
return compiler.results_iter(tuple_expected=True, chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
class NamedValuesListIterable(ValuesListIterable):
"""
Iterable returned by QuerySet.values_list(named=True) that yields a
namedtuple for each row.
"""
def __iter__(self):
queryset = self.queryset
if queryset._fields:
names = queryset._fields
else:
query = queryset.query
names = [*query.extra_select, *query.values_select, *query.annotation_select]
tuple_class = create_namedtuple_class(*names)
new = tuple.__new__
for row in super().__iter__():
yield new(tuple_class, row)
class FlatValuesListIterable(BaseIterable):
"""
Iterable returned by QuerySet.values_list(flat=True) that yields single
values.
"""
def __iter__(self):
queryset = self.queryset
compiler = queryset.query.get_compiler(queryset.db)
for row in compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size):
yield row[0]
class QuerySet:
"""Represent a lazy database lookup for a set of objects."""
def __init__(self, model=None, query=None, using=None, hints=None):
self.model = model
self._db = using
self._hints = hints or {}
self._query = query or sql.Query(self.model)
self._result_cache = None
self._sticky_filter = False
self._for_write = False
self._prefetch_related_lookups = ()
self._prefetch_done = False
self._known_related_objects = {} # {rel_field: {pk: rel_obj}}
self._iterable_class = ModelIterable
self._fields = None
self._defer_next_filter = False
self._deferred_filter = None
@property
def query(self):
if self._deferred_filter:
negate, args, kwargs = self._deferred_filter
self._filter_or_exclude_inplace(negate, args, kwargs)
self._deferred_filter = None
return self._query
@query.setter
def query(self, value):
if value.values_select:
self._iterable_class = ValuesIterable
self._query = value
def as_manager(cls):
# Address the circular dependency between `Queryset` and `Manager`.
from django.db.models.manager import Manager
manager = Manager.from_queryset(cls)()
manager._built_with_as_manager = True
return manager
as_manager.queryset_only = True
as_manager = classmethod(as_manager)
########################
# PYTHON MAGIC METHODS #
########################
def __deepcopy__(self, memo):
"""Don't populate the QuerySet's cache."""
obj = self.__class__()
for k, v in self.__dict__.items():
if k == '_result_cache':
obj.__dict__[k] = None
else:
obj.__dict__[k] = copy.deepcopy(v, memo)
return obj
def __getstate__(self):
# Force the cache to be fully populated.
self._fetch_all()
return {**self.__dict__, DJANGO_VERSION_PICKLE_KEY: django.__version__}
def __setstate__(self, state):
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
if pickled_version != django.__version__:
warnings.warn(
"Pickled queryset instance's Django version %s does not "
"match the current version %s."
% (pickled_version, django.__version__),
RuntimeWarning,
stacklevel=2,
)
else:
warnings.warn(
"Pickled queryset instance's Django version is not specified.",
RuntimeWarning,
stacklevel=2,
)
self.__dict__.update(state)
def __repr__(self):
data = list(self[:REPR_OUTPUT_SIZE + 1])
if len(data) > REPR_OUTPUT_SIZE:
data[-1] = "...(remaining elements truncated)..."
return '<%s %r>' % (self.__class__.__name__, data)
def __len__(self):
self._fetch_all()
return len(self._result_cache)
def __iter__(self):
"""
The queryset iterator protocol uses three nested iterators in the
default case:
1. sql.compiler.execute_sql()
- Returns 100 rows at time (constants.GET_ITERATOR_CHUNK_SIZE)
using cursor.fetchmany(). This part is responsible for
doing some column masking, and returning the rows in chunks.
2. sql.compiler.results_iter()
- Returns one row at time. At this point the rows are still just
tuples. In some cases the return values are converted to
Python values at this location.
3. self.iterator()
- Responsible for turning the rows into model objects.
"""
self._fetch_all()
return iter(self._result_cache)
def __bool__(self):
self._fetch_all()
return bool(self._result_cache)
def __getitem__(self, k):
"""Retrieve an item or slice from the set of results."""
if not isinstance(k, (int, slice)):
raise TypeError(
'QuerySet indices must be integers or slices, not %s.'
% type(k).__name__
)
if (
(isinstance(k, int) and k < 0) or
(isinstance(k, slice) and (
(k.start is not None and k.start < 0) or
(k.stop is not None and k.stop < 0)
))
):
raise ValueError('Negative indexing is not supported.')
if self._result_cache is not None:
return self._result_cache[k]
if isinstance(k, slice):
qs = self._chain()
if k.start is not None:
start = int(k.start)
else:
start = None
if k.stop is not None:
stop = int(k.stop)
else:
stop = None
qs.query.set_limits(start, stop)
return list(qs)[::k.step] if k.step else qs
qs = self._chain()
qs.query.set_limits(k, k + 1)
qs._fetch_all()
return qs._result_cache[0]
def __class_getitem__(cls, *args, **kwargs):
return cls
def __and__(self, other):
self._check_operator_queryset(other, '&')
self._merge_sanity_check(other)
if isinstance(other, EmptyQuerySet):
return other
if isinstance(self, EmptyQuerySet):
return self
combined = self._chain()
combined._merge_known_related_objects(other)
combined.query.combine(other.query, sql.AND)
return combined
def __or__(self, other):
self._check_operator_queryset(other, '|')
self._merge_sanity_check(other)
if isinstance(self, EmptyQuerySet):
return other
if isinstance(other, EmptyQuerySet):
return self
query = self if self.query.can_filter() else self.model._base_manager.filter(pk__in=self.values('pk'))
combined = query._chain()
combined._merge_known_related_objects(other)
if not other.query.can_filter():
other = other.model._base_manager.filter(pk__in=other.values('pk'))
combined.query.combine(other.query, sql.OR)
return combined
####################################
# METHODS THAT DO DATABASE QUERIES #
####################################
def _iterator(self, use_chunked_fetch, chunk_size):
iterable = self._iterable_class(
self,
chunked_fetch=use_chunked_fetch,
chunk_size=chunk_size or 2000,
)
if not self._prefetch_related_lookups or chunk_size is None:
yield from iterable
return
iterator = iter(iterable)
while results := list(islice(iterator, chunk_size)):
prefetch_related_objects(results, *self._prefetch_related_lookups)
yield from results
def iterator(self, chunk_size=None):
"""
An iterator over the results from applying this QuerySet to the
database. chunk_size must be provided for QuerySets that prefetch
related objects. Otherwise, a default chunk_size of 2000 is supplied.
"""
if chunk_size is None:
if self._prefetch_related_lookups:
# When the deprecation ends, replace with:
# raise ValueError(
# 'chunk_size must be provided when using '
# 'QuerySet.iterator() after prefetch_related().'
# )
warnings.warn(
'Using QuerySet.iterator() after prefetch_related() '
'without specifying chunk_size is deprecated.',
category=RemovedInDjango50Warning,
stacklevel=2,
)
elif chunk_size <= 0:
raise ValueError('Chunk size must be strictly positive.')
use_chunked_fetch = not connections[self.db].settings_dict.get('DISABLE_SERVER_SIDE_CURSORS')
return self._iterator(use_chunked_fetch, chunk_size)
def aggregate(self, *args, **kwargs):
"""
Return a dictionary containing the calculations (aggregation)
over the current queryset.
If args is present the expression is passed as a kwarg using
the Aggregate object's default alias.
"""
if self.query.distinct_fields:
raise NotImplementedError("aggregate() + distinct(fields) not implemented.")
self._validate_values_are_expressions((*args, *kwargs.values()), method_name='aggregate')
for arg in args:
# The default_alias property raises TypeError if default_alias
# can't be set automatically or AttributeError if it isn't an
# attribute.
try:
arg.default_alias
except (AttributeError, TypeError):
raise TypeError("Complex aggregates require an alias")
kwargs[arg.default_alias] = arg
query = self.query.chain()
for (alias, aggregate_expr) in kwargs.items():
query.add_annotation(aggregate_expr, alias, is_summary=True)
annotation = query.annotations[alias]
if not annotation.contains_aggregate:
raise TypeError("%s is not an aggregate expression" % alias)
for expr in annotation.get_source_expressions():
if expr.contains_aggregate and isinstance(expr, Ref) and expr.refs in kwargs:
name = expr.refs
raise exceptions.FieldError(
"Cannot compute %s('%s'): '%s' is an aggregate"
% (annotation.name, name, name)
)
return query.get_aggregation(self.db, kwargs)
def count(self):
"""
Perform a SELECT COUNT() and return the number of records as an
integer.
If the QuerySet is already fully cached, return the length of the
cached results set to avoid multiple SELECT COUNT(*) calls.
"""
if self._result_cache is not None:
return len(self._result_cache)
return self.query.get_count(using=self.db)
def get(self, *args, **kwargs):
"""
Perform the query and return a single object matching the given
keyword arguments.
"""
if self.query.combinator and (args or kwargs):
raise NotSupportedError(
'Calling QuerySet.get(...) with filters after %s() is not '
'supported.' % self.query.combinator
)
clone = self._chain() if self.query.combinator else self.filter(*args, **kwargs)
if self.query.can_filter() and not self.query.distinct_fields:
clone = clone.order_by()
limit = None
if not clone.query.select_for_update or connections[clone.db].features.supports_select_for_update_with_limit:
limit = MAX_GET_RESULTS
clone.query.set_limits(high=limit)
num = len(clone)
if num == 1:
return clone._result_cache[0]
if not num:
raise self.model.DoesNotExist(
"%s matching query does not exist." %
self.model._meta.object_name
)
raise self.model.MultipleObjectsReturned(
'get() returned more than one %s -- it returned %s!' % (
self.model._meta.object_name,
num if not limit or num < limit else 'more than %s' % (limit - 1),
)
)
def create(self, **kwargs):
"""
Create a new object with the given kwargs, saving it to the database
and returning the created object.
"""
obj = self.model(**kwargs)
self._for_write = True
obj.save(force_insert=True, using=self.db)
return obj
def _prepare_for_bulk_create(self, objs):
for obj in objs:
if obj.pk is None:
# Populate new PK values.
obj.pk = obj._meta.pk.get_pk_value_on_save(obj)
obj._prepare_related_fields_for_save(operation_name='bulk_create')
def _check_bulk_create_options(self, ignore_conflicts, update_conflicts, update_fields, unique_fields):
if ignore_conflicts and update_conflicts:
raise ValueError(
'ignore_conflicts and update_conflicts are mutually exclusive.'
)
db_features = connections[self.db].features
if ignore_conflicts:
if not db_features.supports_ignore_conflicts:
raise NotSupportedError(
'This database backend does not support ignoring conflicts.'
)
return OnConflict.IGNORE
elif update_conflicts:
if not db_features.supports_update_conflicts:
raise NotSupportedError(
'This database backend does not support updating conflicts.'
)
if not update_fields:
raise ValueError(
'Fields that will be updated when a row insertion fails '
'on conflicts must be provided.'
)
if unique_fields and not db_features.supports_update_conflicts_with_target:
raise NotSupportedError(
'This database backend does not support updating '
'conflicts with specifying unique fields that can trigger '
'the upsert.'
)
if not unique_fields and db_features.supports_update_conflicts_with_target:
raise ValueError(
'Unique fields that can trigger the upsert must be '
'provided.'
)
# Updating primary keys and non-concrete fields is forbidden.
update_fields = [self.model._meta.get_field(name) for name in update_fields]
if any(not f.concrete or f.many_to_many for f in update_fields):
raise ValueError(
'bulk_create() can only be used with concrete fields in '
'update_fields.'
)
if any(f.primary_key for f in update_fields):
raise ValueError(
'bulk_create() cannot be used with primary keys in '
'update_fields.'
)
if unique_fields:
# Primary key is allowed in unique_fields.
unique_fields = [
self.model._meta.get_field(name)
for name in unique_fields if name != 'pk'
]
if any(not f.concrete or f.many_to_many for f in unique_fields):
raise ValueError(
'bulk_create() can only be used with concrete fields '
'in unique_fields.'
)
return OnConflict.UPDATE
return None
def bulk_create(
self, objs, batch_size=None, ignore_conflicts=False,
update_conflicts=False, update_fields=None, unique_fields=None,
):
"""
Insert each of the instances into the database. Do *not* call
save() on each of the instances, do not send any pre/post_save
signals, and do not set the primary key attribute if it is an
autoincrement field (except if features.can_return_rows_from_bulk_insert=True).
Multi-table models are not supported.
"""
# When you bulk insert you don't get the primary keys back (if it's an
# autoincrement, except if can_return_rows_from_bulk_insert=True), so
# you can't insert into the child tables which references this. There
# are two workarounds:
# 1) This could be implemented if you didn't have an autoincrement pk
# 2) You could do it by doing O(n) normal inserts into the parent
# tables to get the primary keys back and then doing a single bulk
# insert into the childmost table.
# We currently set the primary keys on the objects when using
# PostgreSQL via the RETURNING ID clause. It should be possible for
# Oracle as well, but the semantics for extracting the primary keys is
# trickier so it's not done yet.
if batch_size is not None and batch_size <= 0:
raise ValueError('Batch size must be a positive integer.')
# Check that the parents share the same concrete model with the our
# model to detect the inheritance pattern ConcreteGrandParent ->
# MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy
# would not identify that case as involving multiple tables.
for parent in self.model._meta.get_parent_list():
if parent._meta.concrete_model is not self.model._meta.concrete_model:
raise ValueError("Can't bulk create a multi-table inherited model")
if not objs:
return objs
on_conflict = self._check_bulk_create_options(
ignore_conflicts,
update_conflicts,
update_fields,
unique_fields,
)
self._for_write = True
opts = self.model._meta
fields = opts.concrete_fields
objs = list(objs)
self._prepare_for_bulk_create(objs)
with transaction.atomic(using=self.db, savepoint=False):
objs_with_pk, objs_without_pk = partition(lambda o: o.pk is None, objs)
if objs_with_pk:
returned_columns = self._batched_insert(
objs_with_pk,
fields,
batch_size,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
for obj_with_pk, results in zip(objs_with_pk, returned_columns):
for result, field in zip(results, opts.db_returning_fields):
if field != opts.pk:
setattr(obj_with_pk, field.attname, result)
for obj_with_pk in objs_with_pk:
obj_with_pk._state.adding = False
obj_with_pk._state.db = self.db
if objs_without_pk:
fields = [f for f in fields if not isinstance(f, AutoField)]
returned_columns = self._batched_insert(
objs_without_pk,
fields,
batch_size,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
connection = connections[self.db]
if connection.features.can_return_rows_from_bulk_insert and on_conflict is None:
assert len(returned_columns) == len(objs_without_pk)
for obj_without_pk, results in zip(objs_without_pk, returned_columns):
for result, field in zip(results, opts.db_returning_fields):
setattr(obj_without_pk, field.attname, result)
obj_without_pk._state.adding = False
obj_without_pk._state.db = self.db
return objs
def bulk_update(self, objs, fields, batch_size=None):
"""
Update the given fields in each of the given objects in the database.
"""
if batch_size is not None and batch_size < 0:
raise ValueError('Batch size must be a positive integer.')
if not fields:
raise ValueError('Field names must be given to bulk_update().')
objs = tuple(objs)
if any(obj.pk is None for obj in objs):
raise ValueError('All bulk_update() objects must have a primary key set.')
fields = [self.model._meta.get_field(name) for name in fields]
if any(not f.concrete or f.many_to_many for f in fields):
raise ValueError('bulk_update() can only be used with concrete fields.')
if any(f.primary_key for f in fields):
raise ValueError('bulk_update() cannot be used with primary key fields.')
if not objs:
return 0
for obj in objs:
obj._prepare_related_fields_for_save(operation_name='bulk_update', fields=fields)
# PK is used twice in the resulting update query, once in the filter
# and once in the WHEN. Each field will also have one CAST.
connection = connections[self.db]
max_batch_size = connection.ops.bulk_batch_size(['pk', 'pk'] + fields, objs)
batch_size = min(batch_size, max_batch_size) if batch_size else max_batch_size
requires_casting = connection.features.requires_casted_case_in_updates
batches = (objs[i:i + batch_size] for i in range(0, len(objs), batch_size))
updates = []
for batch_objs in batches:
update_kwargs = {}
for field in fields:
when_statements = []
for obj in batch_objs:
attr = getattr(obj, field.attname)
if not hasattr(attr, 'resolve_expression'):
attr = Value(attr, output_field=field)
when_statements.append(When(pk=obj.pk, then=attr))
case_statement = Case(*when_statements, output_field=field)
if requires_casting:
case_statement = Cast(case_statement, output_field=field)
update_kwargs[field.attname] = case_statement
updates.append(([obj.pk for obj in batch_objs], update_kwargs))
rows_updated = 0
with transaction.atomic(using=self.db, savepoint=False):
for pks, update_kwargs in updates:
rows_updated += self.filter(pk__in=pks).update(**update_kwargs)
return rows_updated
bulk_update.alters_data = True
def get_or_create(self, defaults=None, **kwargs):
"""
Look up an object with the given kwargs, creating one if necessary.
Return a tuple of (object, created), where created is a boolean
specifying whether an object was created.
"""
# The get() needs to be targeted at the write database in order
# to avoid potential transaction consistency problems.
self._for_write = True
try:
return self.get(**kwargs), False
except self.model.DoesNotExist:
params = self._extract_model_params(defaults, **kwargs)
# Try to create an object using passed params.
try:
with transaction.atomic(using=self.db):
params = dict(resolve_callables(params))
return self.create(**params), True
except IntegrityError:
try:
return self.get(**kwargs), False
except self.model.DoesNotExist:
pass
raise
def update_or_create(self, defaults=None, **kwargs):
"""
Look up an object with the given kwargs, updating one with defaults
if it exists, otherwise create a new one.
Return a tuple (object, created), where created is a boolean
specifying whether an object was created.
"""
defaults = defaults or {}
self._for_write = True
with transaction.atomic(using=self.db):
# Lock the row so that a concurrent update is blocked until
# update_or_create() has performed its save.
obj, created = self.select_for_update().get_or_create(defaults, **kwargs)
if created:
return obj, created
for k, v in resolve_callables(defaults):
setattr(obj, k, v)
obj.save(using=self.db)
return obj, False
def _extract_model_params(self, defaults, **kwargs):
"""
Prepare `params` for creating a model instance based on the given
kwargs; for use by get_or_create().
"""
defaults = defaults or {}
params = {k: v for k, v in kwargs.items() if LOOKUP_SEP not in k}
params.update(defaults)
property_names = self.model._meta._property_names
invalid_params = []
for param in params:
try:
self.model._meta.get_field(param)
except exceptions.FieldDoesNotExist:
# It's okay to use a model's property if it has a setter.
if not (param in property_names and getattr(self.model, param).fset):
invalid_params.append(param)
if invalid_params:
raise exceptions.FieldError(
"Invalid field name(s) for model %s: '%s'." % (
self.model._meta.object_name,
"', '".join(sorted(invalid_params)),
))
return params
def _earliest(self, *fields):
"""
Return the earliest object according to fields (if given) or by the
model's Meta.get_latest_by.
"""
if fields:
order_by = fields
else:
order_by = getattr(self.model._meta, 'get_latest_by')
if order_by and not isinstance(order_by, (tuple, list)):
order_by = (order_by,)
if order_by is None:
raise ValueError(
"earliest() and latest() require either fields as positional "
"arguments or 'get_latest_by' in the model's Meta."
)
obj = self._chain()
obj.query.set_limits(high=1)
obj.query.clear_ordering(force=True)
obj.query.add_ordering(*order_by)
return obj.get()
def earliest(self, *fields):
if self.query.is_sliced:
raise TypeError('Cannot change a query once a slice has been taken.')
return self._earliest(*fields)
def latest(self, *fields):
if self.query.is_sliced:
raise TypeError('Cannot change a query once a slice has been taken.')
return self.reverse()._earliest(*fields)
def first(self):
"""Return the first object of a query or None if no match is found."""
for obj in (self if self.ordered else self.order_by('pk'))[:1]:
return obj
def last(self):
"""Return the last object of a query or None if no match is found."""
for obj in (self.reverse() if self.ordered else self.order_by('-pk'))[:1]:
return obj
def in_bulk(self, id_list=None, *, field_name='pk'):
"""
Return a dictionary mapping each of the given IDs to the object with
that ID. If `id_list` isn't provided, evaluate the entire QuerySet.
"""
if self.query.is_sliced:
raise TypeError("Cannot use 'limit' or 'offset' with in_bulk().")
opts = self.model._meta
unique_fields = [
constraint.fields[0]
for constraint in opts.total_unique_constraints
if len(constraint.fields) == 1
]
if (
field_name != 'pk' and
not opts.get_field(field_name).unique and
field_name not in unique_fields and
self.query.distinct_fields != (field_name,)
):
raise ValueError("in_bulk()'s field_name must be a unique field but %r isn't." % field_name)
if id_list is not None:
if not id_list:
return {}
filter_key = '{}__in'.format(field_name)
batch_size = connections[self.db].features.max_query_params
id_list = tuple(id_list)
# If the database has a limit on the number of query parameters
# (e.g. SQLite), retrieve objects in batches if necessary.
if batch_size and batch_size < len(id_list):
qs = ()
for offset in range(0, len(id_list), batch_size):
batch = id_list[offset:offset + batch_size]
qs += tuple(self.filter(**{filter_key: batch}).order_by())
else:
qs = self.filter(**{filter_key: id_list}).order_by()
else:
qs = self._chain()
return {getattr(obj, field_name): obj for obj in qs}
def delete(self):
"""Delete the records in the current QuerySet."""
self._not_support_combined_queries('delete')
if self.query.is_sliced:
raise TypeError("Cannot use 'limit' or 'offset' with delete().")
if self.query.distinct or self.query.distinct_fields:
raise TypeError('Cannot call delete() after .distinct().')
if self._fields is not None:
raise TypeError("Cannot call delete() after .values() or .values_list()")
del_query = self._chain()
# The delete is actually 2 queries - one to find related objects,
# and one to delete. Make sure that the discovery of related
# objects is performed on the same database as the deletion.
del_query._for_write = True
# Disable non-supported fields.
del_query.query.select_for_update = False
del_query.query.select_related = False
del_query.query.clear_ordering(force=True)
collector = Collector(using=del_query.db, origin=self)
collector.collect(del_query)
deleted, _rows_count = collector.delete()
# Clear the result cache, in case this QuerySet gets reused.
self._result_cache = None
return deleted, _rows_count
delete.alters_data = True
delete.queryset_only = True
def _raw_delete(self, using):
"""
Delete objects found from the given queryset in single direct SQL
query. No signals are sent and there is no protection for cascades.
"""
query = self.query.clone()
query.__class__ = sql.DeleteQuery
cursor = query.get_compiler(using).execute_sql(CURSOR)
if cursor:
with cursor:
return cursor.rowcount
return 0
_raw_delete.alters_data = True
def update(self, **kwargs):
"""
Update all elements in the current QuerySet, setting all the given
fields to the appropriate values.
"""
self._not_support_combined_queries('update')
if self.query.is_sliced:
raise TypeError('Cannot update a query once a slice has been taken.')
self._for_write = True
query = self.query.chain(sql.UpdateQuery)
query.add_update_values(kwargs)
# Clear any annotations so that they won't be present in subqueries.
query.annotations = {}
with transaction.mark_for_rollback_on_error(using=self.db):
rows = query.get_compiler(self.db).execute_sql(CURSOR)
self._result_cache = None
return rows
update.alters_data = True
def _update(self, values):
"""
A version of update() that accepts field objects instead of field names.
Used primarily for model saving and not intended for use by general
code (it requires too much poking around at model internals to be
useful at that level).
"""
if self.query.is_sliced:
raise TypeError('Cannot update a query once a slice has been taken.')
query = self.query.chain(sql.UpdateQuery)
query.add_update_fields(values)
# Clear any annotations so that they won't be present in subqueries.
query.annotations = {}
self._result_cache = None
return query.get_compiler(self.db).execute_sql(CURSOR)
_update.alters_data = True
_update.queryset_only = False
def exists(self):
if self._result_cache is None:
return self.query.has_results(using=self.db)
return bool(self._result_cache)
def contains(self, obj):
"""Return True if the queryset contains an object."""
self._not_support_combined_queries('contains')
if self._fields is not None:
raise TypeError(
'Cannot call QuerySet.contains() after .values() or '
'.values_list().'
)
try:
if obj._meta.concrete_model != self.model._meta.concrete_model:
return False
except AttributeError:
raise TypeError("'obj' must be a model instance.")
if obj.pk is None:
raise ValueError(
'QuerySet.contains() cannot be used on unsaved objects.'
)
if self._result_cache is not None:
return obj in self._result_cache
return self.filter(pk=obj.pk).exists()
def _prefetch_related_objects(self):
# This method can only be called once the result cache has been filled.
prefetch_related_objects(self._result_cache, *self._prefetch_related_lookups)
self._prefetch_done = True
def explain(self, *, format=None, **options):
return self.query.explain(using=self.db, format=format, **options)
##################################################
# PUBLIC METHODS THAT RETURN A QUERYSET SUBCLASS #
##################################################
def raw(self, raw_query, params=(), translations=None, using=None):
if using is None:
using = self.db
qs = RawQuerySet(raw_query, model=self.model, params=params, translations=translations, using=using)
qs._prefetch_related_lookups = self._prefetch_related_lookups[:]
return qs
def _values(self, *fields, **expressions):
clone = self._chain()
if expressions:
clone = clone.annotate(**expressions)
clone._fields = fields
clone.query.set_values(fields)
return clone
def values(self, *fields, **expressions):
fields += tuple(expressions)
clone = self._values(*fields, **expressions)
clone._iterable_class = ValuesIterable
return clone
def values_list(self, *fields, flat=False, named=False):
if flat and named:
raise TypeError("'flat' and 'named' can't be used together.")
if flat and len(fields) > 1:
raise TypeError("'flat' is not valid when values_list is called with more than one field.")
field_names = {f for f in fields if not hasattr(f, 'resolve_expression')}
_fields = []
expressions = {}
counter = 1
for field in fields:
if hasattr(field, 'resolve_expression'):
field_id_prefix = getattr(field, 'default_alias', field.__class__.__name__.lower())
while True:
field_id = field_id_prefix + str(counter)
counter += 1
if field_id not in field_names:
break
expressions[field_id] = field
_fields.append(field_id)
else:
_fields.append(field)
clone = self._values(*_fields, **expressions)
clone._iterable_class = (
NamedValuesListIterable if named
else FlatValuesListIterable if flat
else ValuesListIterable
)
return clone
def dates(self, field_name, kind, order='ASC'):
"""
Return a list of date objects representing all available dates for
the given field_name, scoped to 'kind'.
"""
if kind not in ('year', 'month', 'week', 'day'):
raise ValueError("'kind' must be one of 'year', 'month', 'week', or 'day'.")
if order not in ('ASC', 'DESC'):
raise ValueError("'order' must be either 'ASC' or 'DESC'.")
return self.annotate(
datefield=Trunc(field_name, kind, output_field=DateField()),
plain_field=F(field_name)
).values_list(
'datefield', flat=True
).distinct().filter(plain_field__isnull=False).order_by(('-' if order == 'DESC' else '') + 'datefield')
# RemovedInDjango50Warning: when the deprecation ends, remove is_dst
# argument.
def datetimes(self, field_name, kind, order='ASC', tzinfo=None, is_dst=timezone.NOT_PASSED):
"""
Return a list of datetime objects representing all available
datetimes for the given field_name, scoped to 'kind'.
"""
if kind not in ('year', 'month', 'week', 'day', 'hour', 'minute', 'second'):
raise ValueError(
"'kind' must be one of 'year', 'month', 'week', 'day', "
"'hour', 'minute', or 'second'."
)
if order not in ('ASC', 'DESC'):
raise ValueError("'order' must be either 'ASC' or 'DESC'.")
if settings.USE_TZ:
if tzinfo is None:
tzinfo = timezone.get_current_timezone()
else:
tzinfo = None
return self.annotate(
datetimefield=Trunc(
field_name,
kind,
output_field=DateTimeField(),
tzinfo=tzinfo,
is_dst=is_dst,
),
plain_field=F(field_name)
).values_list(
'datetimefield', flat=True
).distinct().filter(plain_field__isnull=False).order_by(('-' if order == 'DESC' else '') + 'datetimefield')
def none(self):
"""Return an empty QuerySet."""
clone = self._chain()
clone.query.set_empty()
return clone
##################################################################
# PUBLIC METHODS THAT ALTER ATTRIBUTES AND RETURN A NEW QUERYSET #
##################################################################
def all(self):
"""
Return a new QuerySet that is a copy of the current one. This allows a
QuerySet to proxy for a model manager in some cases.
"""
return self._chain()
def filter(self, *args, **kwargs):
"""
Return a new QuerySet instance with the args ANDed to the existing
set.
"""
self._not_support_combined_queries('filter')
return self._filter_or_exclude(False, args, kwargs)
def exclude(self, *args, **kwargs):
"""
Return a new QuerySet instance with NOT (args) ANDed to the existing
set.
"""
self._not_support_combined_queries('exclude')
return self._filter_or_exclude(True, args, kwargs)
def _filter_or_exclude(self, negate, args, kwargs):
if (args or kwargs) and self.query.is_sliced:
raise TypeError('Cannot filter a query once a slice has been taken.')
clone = self._chain()
if self._defer_next_filter:
self._defer_next_filter = False
clone._deferred_filter = negate, args, kwargs
else:
clone._filter_or_exclude_inplace(negate, args, kwargs)
return clone
def _filter_or_exclude_inplace(self, negate, args, kwargs):
if negate:
self._query.add_q(~Q(*args, **kwargs))
else:
self._query.add_q(Q(*args, **kwargs))
def complex_filter(self, filter_obj):
"""
Return a new QuerySet instance with filter_obj added to the filters.
filter_obj can be a Q object or a dictionary of keyword lookup
arguments.
This exists to support framework features such as 'limit_choices_to',
and usually it will be more natural to use other methods.
"""
if isinstance(filter_obj, Q):
clone = self._chain()
clone.query.add_q(filter_obj)
return clone
else:
return self._filter_or_exclude(False, args=(), kwargs=filter_obj)
def _combinator_query(self, combinator, *other_qs, all=False):
# Clone the query to inherit the select list and everything
clone = self._chain()
# Clear limits and ordering so they can be reapplied
clone.query.clear_ordering(force=True)
clone.query.clear_limits()
clone.query.combined_queries = (self.query,) + tuple(qs.query for qs in other_qs)
clone.query.combinator = combinator
clone.query.combinator_all = all
return clone
def union(self, *other_qs, all=False):
# If the query is an EmptyQuerySet, combine all nonempty querysets.
if isinstance(self, EmptyQuerySet):
qs = [q for q in other_qs if not isinstance(q, EmptyQuerySet)]
if not qs:
return self
if len(qs) == 1:
return qs[0]
return qs[0]._combinator_query('union', *qs[1:], all=all)
return self._combinator_query('union', *other_qs, all=all)
def intersection(self, *other_qs):
# If any query is an EmptyQuerySet, return it.
if isinstance(self, EmptyQuerySet):
return self
for other in other_qs:
if isinstance(other, EmptyQuerySet):
return other
return self._combinator_query('intersection', *other_qs)
def difference(self, *other_qs):
# If the query is an EmptyQuerySet, return it.
if isinstance(self, EmptyQuerySet):
return self
return self._combinator_query('difference', *other_qs)
def select_for_update(self, nowait=False, skip_locked=False, of=(), no_key=False):
"""
Return a new QuerySet instance that will select objects with a
FOR UPDATE lock.
"""
if nowait and skip_locked:
raise ValueError('The nowait option cannot be used with skip_locked.')
obj = self._chain()
obj._for_write = True
obj.query.select_for_update = True
obj.query.select_for_update_nowait = nowait
obj.query.select_for_update_skip_locked = skip_locked
obj.query.select_for_update_of = of
obj.query.select_for_no_key_update = no_key
return obj
def select_related(self, *fields):
"""
Return a new QuerySet instance that will select related objects.
If fields are specified, they must be ForeignKey fields and only those
related objects are included in the selection.
If select_related(None) is called, clear the list.
"""
self._not_support_combined_queries('select_related')
if self._fields is not None:
raise TypeError("Cannot call select_related() after .values() or .values_list()")
obj = self._chain()
if fields == (None,):
obj.query.select_related = False
elif fields:
obj.query.add_select_related(fields)
else:
obj.query.select_related = True
return obj
def prefetch_related(self, *lookups):
"""
Return a new QuerySet instance that will prefetch the specified
Many-To-One and Many-To-Many related objects when the QuerySet is
evaluated.
When prefetch_related() is called more than once, append to the list of
prefetch lookups. If prefetch_related(None) is called, clear the list.
"""
self._not_support_combined_queries('prefetch_related')
clone = self._chain()
if lookups == (None,):
clone._prefetch_related_lookups = ()
else:
for lookup in lookups:
if isinstance(lookup, Prefetch):
lookup = lookup.prefetch_to
lookup = lookup.split(LOOKUP_SEP, 1)[0]
if lookup in self.query._filtered_relations:
raise ValueError('prefetch_related() is not supported with FilteredRelation.')
clone._prefetch_related_lookups = clone._prefetch_related_lookups + lookups
return clone
def annotate(self, *args, **kwargs):
"""
Return a query set in which the returned objects have been annotated
with extra data or aggregations.
"""
self._not_support_combined_queries('annotate')
return self._annotate(args, kwargs, select=True)
def alias(self, *args, **kwargs):
"""
Return a query set with added aliases for extra data or aggregations.
"""
self._not_support_combined_queries('alias')
return self._annotate(args, kwargs, select=False)
def _annotate(self, args, kwargs, select=True):
self._validate_values_are_expressions(args + tuple(kwargs.values()), method_name='annotate')
annotations = {}
for arg in args:
# The default_alias property may raise a TypeError.
try:
if arg.default_alias in kwargs:
raise ValueError("The named annotation '%s' conflicts with the "
"default name for another annotation."
% arg.default_alias)
except TypeError:
raise TypeError("Complex annotations require an alias")
annotations[arg.default_alias] = arg
annotations.update(kwargs)
clone = self._chain()
names = self._fields
if names is None:
names = set(chain.from_iterable(
(field.name, field.attname) if hasattr(field, 'attname') else (field.name,)
for field in self.model._meta.get_fields()
))
for alias, annotation in annotations.items():
if alias in names:
raise ValueError("The annotation '%s' conflicts with a field on "
"the model." % alias)
if isinstance(annotation, FilteredRelation):
clone.query.add_filtered_relation(annotation, alias)
else:
clone.query.add_annotation(
annotation, alias, is_summary=False, select=select,
)
for alias, annotation in clone.query.annotations.items():
if alias in annotations and annotation.contains_aggregate:
if clone._fields is None:
clone.query.group_by = True
else:
clone.query.set_group_by()
break
return clone
def order_by(self, *field_names):
"""Return a new QuerySet instance with the ordering changed."""
if self.query.is_sliced:
raise TypeError('Cannot reorder a query once a slice has been taken.')
obj = self._chain()
obj.query.clear_ordering(force=True, clear_default=False)
obj.query.add_ordering(*field_names)
return obj
def distinct(self, *field_names):
"""
Return a new QuerySet instance that will select only distinct results.
"""
self._not_support_combined_queries('distinct')
if self.query.is_sliced:
raise TypeError('Cannot create distinct fields once a slice has been taken.')
obj = self._chain()
obj.query.add_distinct_fields(*field_names)
return obj
def extra(self, select=None, where=None, params=None, tables=None,
order_by=None, select_params=None):
"""Add extra SQL fragments to the query."""
self._not_support_combined_queries('extra')
if self.query.is_sliced:
raise TypeError('Cannot change a query once a slice has been taken.')
clone = self._chain()
clone.query.add_extra(select, select_params, where, params, tables, order_by)
return clone
def reverse(self):
"""Reverse the ordering of the QuerySet."""
if self.query.is_sliced:
raise TypeError('Cannot reverse a query once a slice has been taken.')
clone = self._chain()
clone.query.standard_ordering = not clone.query.standard_ordering
return clone
def defer(self, *fields):
"""
Defer the loading of data for certain fields until they are accessed.
Add the set of deferred fields to any existing set of deferred fields.
The only exception to this is if None is passed in as the only
parameter, in which case removal all deferrals.
"""
self._not_support_combined_queries('defer')
if self._fields is not None:
raise TypeError("Cannot call defer() after .values() or .values_list()")
clone = self._chain()
if fields == (None,):
clone.query.clear_deferred_loading()
else:
clone.query.add_deferred_loading(fields)
return clone
def only(self, *fields):
"""
Essentially, the opposite of defer(). Only the fields passed into this
method and that are not already specified as deferred are loaded
immediately when the queryset is evaluated.
"""
self._not_support_combined_queries('only')
if self._fields is not None:
raise TypeError("Cannot call only() after .values() or .values_list()")
if fields == (None,):
# Can only pass None to defer(), not only(), as the rest option.
# That won't stop people trying to do this, so let's be explicit.
raise TypeError("Cannot pass None as an argument to only().")
for field in fields:
field = field.split(LOOKUP_SEP, 1)[0]
if field in self.query._filtered_relations:
raise ValueError('only() is not supported with FilteredRelation.')
clone = self._chain()
clone.query.add_immediate_loading(fields)
return clone
def using(self, alias):
"""Select which database this QuerySet should execute against."""
clone = self._chain()
clone._db = alias
return clone
###################################
# PUBLIC INTROSPECTION ATTRIBUTES #
###################################
@property
def ordered(self):
"""
Return True if the QuerySet is ordered -- i.e. has an order_by()
clause or a default ordering on the model (or is empty).
"""
if isinstance(self, EmptyQuerySet):
return True
if self.query.extra_order_by or self.query.order_by:
return True
elif (
self.query.default_ordering and
self.query.get_meta().ordering and
# A default ordering doesn't affect GROUP BY queries.
not self.query.group_by
):
return True
else:
return False
@property
def db(self):
"""Return the database used if this query is executed now."""
if self._for_write:
return self._db or router.db_for_write(self.model, **self._hints)
return self._db or router.db_for_read(self.model, **self._hints)
###################
# PRIVATE METHODS #
###################
def _insert(
self, objs, fields, returning_fields=None, raw=False, using=None,
on_conflict=None, update_fields=None, unique_fields=None,
):
"""
Insert a new record for the given model. This provides an interface to
the InsertQuery class and is how Model.save() is implemented.
"""
self._for_write = True
if using is None:
using = self.db
query = sql.InsertQuery(
self.model,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
query.insert_values(fields, objs, raw=raw)
return query.get_compiler(using=using).execute_sql(returning_fields)
_insert.alters_data = True
_insert.queryset_only = False
def _batched_insert(
self, objs, fields, batch_size, on_conflict=None, update_fields=None,
unique_fields=None,
):
"""
Helper method for bulk_create() to insert objs one batch at a time.
"""
connection = connections[self.db]
ops = connection.ops
max_batch_size = max(ops.bulk_batch_size(fields, objs), 1)
batch_size = min(batch_size, max_batch_size) if batch_size else max_batch_size
inserted_rows = []
bulk_return = connection.features.can_return_rows_from_bulk_insert
for item in [objs[i:i + batch_size] for i in range(0, len(objs), batch_size)]:
if bulk_return and on_conflict is None:
inserted_rows.extend(self._insert(
item, fields=fields, using=self.db,
returning_fields=self.model._meta.db_returning_fields,
))
else:
self._insert(
item,
fields=fields,
using=self.db,
on_conflict=on_conflict,
update_fields=update_fields,
unique_fields=unique_fields,
)
return inserted_rows
def _chain(self):
"""
Return a copy of the current QuerySet that's ready for another
operation.
"""
obj = self._clone()
if obj._sticky_filter:
obj.query.filter_is_sticky = True
obj._sticky_filter = False
return obj
def _clone(self):
"""
Return a copy of the current QuerySet. A lightweight alternative
to deepcopy().
"""
c = self.__class__(model=self.model, query=self.query.chain(), using=self._db, hints=self._hints)
c._sticky_filter = self._sticky_filter
c._for_write = self._for_write
c._prefetch_related_lookups = self._prefetch_related_lookups[:]
c._known_related_objects = self._known_related_objects
c._iterable_class = self._iterable_class
c._fields = self._fields
return c
def _fetch_all(self):
if self._result_cache is None:
self._result_cache = list(self._iterable_class(self))
if self._prefetch_related_lookups and not self._prefetch_done:
self._prefetch_related_objects()
def _next_is_sticky(self):
"""
Indicate that the next filter call and the one following that should
be treated as a single filter. This is only important when it comes to
determining when to reuse tables for many-to-many filters. Required so
that we can filter naturally on the results of related managers.
This doesn't return a clone of the current QuerySet (it returns
"self"). The method is only used internally and should be immediately
followed by a filter() that does create a clone.
"""
self._sticky_filter = True
return self
def _merge_sanity_check(self, other):
"""Check that two QuerySet classes may be merged."""
if self._fields is not None and (
set(self.query.values_select) != set(other.query.values_select) or
set(self.query.extra_select) != set(other.query.extra_select) or
set(self.query.annotation_select) != set(other.query.annotation_select)):
raise TypeError(
"Merging '%s' classes must involve the same values in each case."
% self.__class__.__name__
)
def _merge_known_related_objects(self, other):
"""
Keep track of all known related objects from either QuerySet instance.
"""
for field, objects in other._known_related_objects.items():
self._known_related_objects.setdefault(field, {}).update(objects)
def resolve_expression(self, *args, **kwargs):
if self._fields and len(self._fields) > 1:
# values() queryset can only be used as nested queries
# if they are set up to select only a single field.
raise TypeError('Cannot use multi-field values as a filter value.')
query = self.query.resolve_expression(*args, **kwargs)
query._db = self._db
return query
resolve_expression.queryset_only = True
def _add_hints(self, **hints):
"""
Update hinting information for use by routers. Add new key/values or
overwrite existing key/values.
"""
self._hints.update(hints)
def _has_filters(self):
"""
Check if this QuerySet has any filtering going on. This isn't
equivalent with checking if all objects are present in results, for
example, qs[1:]._has_filters() -> False.
"""
return self.query.has_filters()
@staticmethod
def _validate_values_are_expressions(values, method_name):
invalid_args = sorted(str(arg) for arg in values if not hasattr(arg, 'resolve_expression'))
if invalid_args:
raise TypeError(
'QuerySet.%s() received non-expression(s): %s.' % (
method_name,
', '.join(invalid_args),
)
)
def _not_support_combined_queries(self, operation_name):
if self.query.combinator:
raise NotSupportedError(
'Calling QuerySet.%s() after %s() is not supported.'
% (operation_name, self.query.combinator)
)
def _check_operator_queryset(self, other, operator_):
if self.query.combinator or other.query.combinator:
raise TypeError(f'Cannot use {operator_} operator with combined queryset.')
class InstanceCheckMeta(type):
def __instancecheck__(self, instance):
return isinstance(instance, QuerySet) and instance.query.is_empty()
class EmptyQuerySet(metaclass=InstanceCheckMeta):
"""
Marker class to checking if a queryset is empty by .none():
isinstance(qs.none(), EmptyQuerySet) -> True
"""
def __init__(self, *args, **kwargs):
raise TypeError("EmptyQuerySet can't be instantiated")
class RawQuerySet:
"""
Provide an iterator which converts the results of raw SQL queries into
annotated model instances.
"""
def __init__(self, raw_query, model=None, query=None, params=(),
translations=None, using=None, hints=None):
self.raw_query = raw_query
self.model = model
self._db = using
self._hints = hints or {}
self.query = query or sql.RawQuery(sql=raw_query, using=self.db, params=params)
self.params = params
self.translations = translations or {}
self._result_cache = None
self._prefetch_related_lookups = ()
self._prefetch_done = False
def resolve_model_init_order(self):
"""Resolve the init field names and value positions."""
converter = connections[self.db].introspection.identifier_converter
model_init_fields = [f for f in self.model._meta.fields if converter(f.column) in self.columns]
annotation_fields = [(column, pos) for pos, column in enumerate(self.columns)
if column not in self.model_fields]
model_init_order = [self.columns.index(converter(f.column)) for f in model_init_fields]
model_init_names = [f.attname for f in model_init_fields]
return model_init_names, model_init_order, annotation_fields
def prefetch_related(self, *lookups):
"""Same as QuerySet.prefetch_related()"""
clone = self._clone()
if lookups == (None,):
clone._prefetch_related_lookups = ()
else:
clone._prefetch_related_lookups = clone._prefetch_related_lookups + lookups
return clone
def _prefetch_related_objects(self):
prefetch_related_objects(self._result_cache, *self._prefetch_related_lookups)
self._prefetch_done = True
def _clone(self):
"""Same as QuerySet._clone()"""
c = self.__class__(
self.raw_query, model=self.model, query=self.query, params=self.params,
translations=self.translations, using=self._db, hints=self._hints
)
c._prefetch_related_lookups = self._prefetch_related_lookups[:]
return c
def _fetch_all(self):
if self._result_cache is None:
self._result_cache = list(self.iterator())
if self._prefetch_related_lookups and not self._prefetch_done:
self._prefetch_related_objects()
def __len__(self):
self._fetch_all()
return len(self._result_cache)
def __bool__(self):
self._fetch_all()
return bool(self._result_cache)
def __iter__(self):
self._fetch_all()
return iter(self._result_cache)
def iterator(self):
# Cache some things for performance reasons outside the loop.
db = self.db
connection = connections[db]
compiler = connection.ops.compiler('SQLCompiler')(self.query, connection, db)
query = iter(self.query)
try:
model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()
if self.model._meta.pk.attname not in model_init_names:
raise exceptions.FieldDoesNotExist(
'Raw query must include the primary key'
)
model_cls = self.model
fields = [self.model_fields.get(c) for c in self.columns]
converters = compiler.get_converters([
f.get_col(f.model._meta.db_table) if f else None for f in fields
])
if converters:
query = compiler.apply_converters(query, converters)
for values in query:
# Associate fields to values
model_init_values = [values[pos] for pos in model_init_pos]
instance = model_cls.from_db(db, model_init_names, model_init_values)
if annotation_fields:
for column, pos in annotation_fields:
setattr(instance, column, values[pos])
yield instance
finally:
# Done iterating the Query. If it has its own cursor, close it.
if hasattr(self.query, 'cursor') and self.query.cursor:
self.query.cursor.close()
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self.query)
def __getitem__(self, k):
return list(self)[k]
@property
def db(self):
"""Return the database used if this query is executed now."""
return self._db or router.db_for_read(self.model, **self._hints)
def using(self, alias):
"""Select the database this RawQuerySet should execute against."""
return RawQuerySet(
self.raw_query, model=self.model,
query=self.query.chain(using=alias),
params=self.params, translations=self.translations,
using=alias,
)
@cached_property
def columns(self):
"""
A list of model field names in the order they'll appear in the
query results.
"""
columns = self.query.get_columns()
# Adjust any column names which don't match field names
for (query_name, model_name) in self.translations.items():
# Ignore translations for nonexistent column names
try:
index = columns.index(query_name)
except ValueError:
pass
else:
columns[index] = model_name
return columns
@cached_property
def model_fields(self):
"""A dict mapping column names to model field names."""
converter = connections[self.db].introspection.identifier_converter
model_fields = {}
for field in self.model._meta.fields:
name, column = field.get_attname_column()
model_fields[converter(column)] = field
return model_fields
class Prefetch:
def __init__(self, lookup, queryset=None, to_attr=None):
# `prefetch_through` is the path we traverse to perform the prefetch.
self.prefetch_through = lookup
# `prefetch_to` is the path to the attribute that stores the result.
self.prefetch_to = lookup
if queryset is not None and (
isinstance(queryset, RawQuerySet) or (
hasattr(queryset, '_iterable_class') and
not issubclass(queryset._iterable_class, ModelIterable)
)
):
raise ValueError(
'Prefetch querysets cannot use raw(), values(), and '
'values_list().'
)
if to_attr:
self.prefetch_to = LOOKUP_SEP.join(lookup.split(LOOKUP_SEP)[:-1] + [to_attr])
self.queryset = queryset
self.to_attr = to_attr
def __getstate__(self):
obj_dict = self.__dict__.copy()
if self.queryset is not None:
queryset = self.queryset._chain()
# Prevent the QuerySet from being evaluated
queryset._result_cache = []
queryset._prefetch_done = True
obj_dict['queryset'] = queryset
return obj_dict
def add_prefix(self, prefix):
self.prefetch_through = prefix + LOOKUP_SEP + self.prefetch_through
self.prefetch_to = prefix + LOOKUP_SEP + self.prefetch_to
def get_current_prefetch_to(self, level):
return LOOKUP_SEP.join(self.prefetch_to.split(LOOKUP_SEP)[:level + 1])
def get_current_to_attr(self, level):
parts = self.prefetch_to.split(LOOKUP_SEP)
to_attr = parts[level]
as_attr = self.to_attr and level == len(parts) - 1
return to_attr, as_attr
def get_current_queryset(self, level):
if self.get_current_prefetch_to(level) == self.prefetch_to:
return self.queryset
return None
def __eq__(self, other):
if not isinstance(other, Prefetch):
return NotImplemented
return self.prefetch_to == other.prefetch_to
def __hash__(self):
return hash((self.__class__, self.prefetch_to))
def normalize_prefetch_lookups(lookups, prefix=None):
"""Normalize lookups into Prefetch objects."""
ret = []
for lookup in lookups:
if not isinstance(lookup, Prefetch):
lookup = Prefetch(lookup)
if prefix:
lookup.add_prefix(prefix)
ret.append(lookup)
return ret
def prefetch_related_objects(model_instances, *related_lookups):
"""
Populate prefetched object caches for a list of model instances based on
the lookups/Prefetch instances given.
"""
if not model_instances:
return # nothing to do
# We need to be able to dynamically add to the list of prefetch_related
# lookups that we look up (see below). So we need some book keeping to
# ensure we don't do duplicate work.
done_queries = {} # dictionary of things like 'foo__bar': [results]
auto_lookups = set() # we add to this as we go through.
followed_descriptors = set() # recursion protection
all_lookups = normalize_prefetch_lookups(reversed(related_lookups))
while all_lookups:
lookup = all_lookups.pop()
if lookup.prefetch_to in done_queries:
if lookup.queryset is not None:
raise ValueError("'%s' lookup was already seen with a different queryset. "
"You may need to adjust the ordering of your lookups." % lookup.prefetch_to)
continue
# Top level, the list of objects to decorate is the result cache
# from the primary QuerySet. It won't be for deeper levels.
obj_list = model_instances
through_attrs = lookup.prefetch_through.split(LOOKUP_SEP)
for level, through_attr in enumerate(through_attrs):
# Prepare main instances
if not obj_list:
break
prefetch_to = lookup.get_current_prefetch_to(level)
if prefetch_to in done_queries:
# Skip any prefetching, and any object preparation
obj_list = done_queries[prefetch_to]
continue
# Prepare objects:
good_objects = True
for obj in obj_list:
# Since prefetching can re-use instances, it is possible to have
# the same instance multiple times in obj_list, so obj might
# already be prepared.
if not hasattr(obj, '_prefetched_objects_cache'):
try:
obj._prefetched_objects_cache = {}
except (AttributeError, TypeError):
# Must be an immutable object from
# values_list(flat=True), for example (TypeError) or
# a QuerySet subclass that isn't returning Model
# instances (AttributeError), either in Django or a 3rd
# party. prefetch_related() doesn't make sense, so quit.
good_objects = False
break
if not good_objects:
break
# Descend down tree
# We assume that objects retrieved are homogeneous (which is the premise
# of prefetch_related), so what applies to first object applies to all.
first_obj = obj_list[0]
to_attr = lookup.get_current_to_attr(level)[0]
prefetcher, descriptor, attr_found, is_fetched = get_prefetcher(first_obj, through_attr, to_attr)
if not attr_found:
raise AttributeError("Cannot find '%s' on %s object, '%s' is an invalid "
"parameter to prefetch_related()" %
(through_attr, first_obj.__class__.__name__, lookup.prefetch_through))
if level == len(through_attrs) - 1 and prefetcher is None:
# Last one, this *must* resolve to something that supports
# prefetching, otherwise there is no point adding it and the
# developer asking for it has made a mistake.
raise ValueError("'%s' does not resolve to an item that supports "
"prefetching - this is an invalid parameter to "
"prefetch_related()." % lookup.prefetch_through)
obj_to_fetch = None
if prefetcher is not None:
obj_to_fetch = [obj for obj in obj_list if not is_fetched(obj)]
if obj_to_fetch:
obj_list, additional_lookups = prefetch_one_level(
obj_to_fetch,
prefetcher,
lookup,
level,
)
# We need to ensure we don't keep adding lookups from the
# same relationships to stop infinite recursion. So, if we
# are already on an automatically added lookup, don't add
# the new lookups from relationships we've seen already.
if not (prefetch_to in done_queries and lookup in auto_lookups and descriptor in followed_descriptors):
done_queries[prefetch_to] = obj_list
new_lookups = normalize_prefetch_lookups(reversed(additional_lookups), prefetch_to)
auto_lookups.update(new_lookups)
all_lookups.extend(new_lookups)
followed_descriptors.add(descriptor)
else:
# Either a singly related object that has already been fetched
# (e.g. via select_related), or hopefully some other property
# that doesn't support prefetching but needs to be traversed.
# We replace the current list of parent objects with the list
# of related objects, filtering out empty or missing values so
# that we can continue with nullable or reverse relations.
new_obj_list = []
for obj in obj_list:
if through_attr in getattr(obj, '_prefetched_objects_cache', ()):
# If related objects have been prefetched, use the
# cache rather than the object's through_attr.
new_obj = list(obj._prefetched_objects_cache.get(through_attr))
else:
try:
new_obj = getattr(obj, through_attr)
except exceptions.ObjectDoesNotExist:
continue
if new_obj is None:
continue
# We special-case `list` rather than something more generic
# like `Iterable` because we don't want to accidentally match
# user models that define __iter__.
if isinstance(new_obj, list):
new_obj_list.extend(new_obj)
else:
new_obj_list.append(new_obj)
obj_list = new_obj_list
def get_prefetcher(instance, through_attr, to_attr):
"""
For the attribute 'through_attr' on the given instance, find
an object that has a get_prefetch_queryset().
Return a 4 tuple containing:
(the object with get_prefetch_queryset (or None),
the descriptor object representing this relationship (or None),
a boolean that is False if the attribute was not found at all,
a function that takes an instance and returns a boolean that is True if
the attribute has already been fetched for that instance)
"""
def has_to_attr_attribute(instance):
return hasattr(instance, to_attr)
prefetcher = None
is_fetched = has_to_attr_attribute
# For singly related objects, we have to avoid getting the attribute
# from the object, as this will trigger the query. So we first try
# on the class, in order to get the descriptor object.
rel_obj_descriptor = getattr(instance.__class__, through_attr, None)
if rel_obj_descriptor is None:
attr_found = hasattr(instance, through_attr)
else:
attr_found = True
if rel_obj_descriptor:
# singly related object, descriptor object has the
# get_prefetch_queryset() method.
if hasattr(rel_obj_descriptor, 'get_prefetch_queryset'):
prefetcher = rel_obj_descriptor
is_fetched = rel_obj_descriptor.is_cached
else:
# descriptor doesn't support prefetching, so we go ahead and get
# the attribute on the instance rather than the class to
# support many related managers
rel_obj = getattr(instance, through_attr)
if hasattr(rel_obj, 'get_prefetch_queryset'):
prefetcher = rel_obj
if through_attr != to_attr:
# Special case cached_property instances because hasattr
# triggers attribute computation and assignment.
if isinstance(getattr(instance.__class__, to_attr, None), cached_property):
def has_cached_property(instance):
return to_attr in instance.__dict__
is_fetched = has_cached_property
else:
def in_prefetched_cache(instance):
return through_attr in instance._prefetched_objects_cache
is_fetched = in_prefetched_cache
return prefetcher, rel_obj_descriptor, attr_found, is_fetched
def prefetch_one_level(instances, prefetcher, lookup, level):
"""
Helper function for prefetch_related_objects().
Run prefetches on all instances using the prefetcher object,
assigning results to relevant caches in instance.
Return the prefetched objects along with any additional prefetches that
must be done due to prefetch_related lookups found from default managers.
"""
# prefetcher must have a method get_prefetch_queryset() which takes a list
# of instances, and returns a tuple:
# (queryset of instances of self.model that are related to passed in instances,
# callable that gets value to be matched for returned instances,
# callable that gets value to be matched for passed in instances,
# boolean that is True for singly related objects,
# cache or field name to assign to,
# boolean that is True when the previous argument is a cache name vs a field name).
# The 'values to be matched' must be hashable as they will be used
# in a dictionary.
rel_qs, rel_obj_attr, instance_attr, single, cache_name, is_descriptor = (
prefetcher.get_prefetch_queryset(instances, lookup.get_current_queryset(level)))
# We have to handle the possibility that the QuerySet we just got back
# contains some prefetch_related lookups. We don't want to trigger the
# prefetch_related functionality by evaluating the query. Rather, we need
# to merge in the prefetch_related lookups.
# Copy the lookups in case it is a Prefetch object which could be reused
# later (happens in nested prefetch_related).
additional_lookups = [
copy.copy(additional_lookup) for additional_lookup
in getattr(rel_qs, '_prefetch_related_lookups', ())
]
if additional_lookups:
# Don't need to clone because the manager should have given us a fresh
# instance, so we access an internal instead of using public interface
# for performance reasons.
rel_qs._prefetch_related_lookups = ()
all_related_objects = list(rel_qs)
rel_obj_cache = {}
for rel_obj in all_related_objects:
rel_attr_val = rel_obj_attr(rel_obj)
rel_obj_cache.setdefault(rel_attr_val, []).append(rel_obj)
to_attr, as_attr = lookup.get_current_to_attr(level)
# Make sure `to_attr` does not conflict with a field.
if as_attr and instances:
# We assume that objects retrieved are homogeneous (which is the premise
# of prefetch_related), so what applies to first object applies to all.
model = instances[0].__class__
try:
model._meta.get_field(to_attr)
except exceptions.FieldDoesNotExist:
pass
else:
msg = 'to_attr={} conflicts with a field on the {} model.'
raise ValueError(msg.format(to_attr, model.__name__))
# Whether or not we're prefetching the last part of the lookup.
leaf = len(lookup.prefetch_through.split(LOOKUP_SEP)) - 1 == level
for obj in instances:
instance_attr_val = instance_attr(obj)
vals = rel_obj_cache.get(instance_attr_val, [])
if single:
val = vals[0] if vals else None
if as_attr:
# A to_attr has been given for the prefetch.
setattr(obj, to_attr, val)
elif is_descriptor:
# cache_name points to a field name in obj.
# This field is a descriptor for a related object.
setattr(obj, cache_name, val)
else:
# No to_attr has been given for this prefetch operation and the
# cache_name does not point to a descriptor. Store the value of
# the field in the object's field cache.
obj._state.fields_cache[cache_name] = val
else:
if as_attr:
setattr(obj, to_attr, vals)
else:
manager = getattr(obj, to_attr)
if leaf and lookup.queryset is not None:
qs = manager._apply_rel_filters(lookup.queryset)
else:
qs = manager.get_queryset()
qs._result_cache = vals
# We don't want the individual qs doing prefetch_related now,
# since we have merged this into the current work.
qs._prefetch_done = True
obj._prefetched_objects_cache[cache_name] = qs
return all_related_objects, additional_lookups
class RelatedPopulator:
"""
RelatedPopulator is used for select_related() object instantiation.
The idea is that each select_related() model will be populated by a
different RelatedPopulator instance. The RelatedPopulator instances get
klass_info and select (computed in SQLCompiler) plus the used db as
input for initialization. That data is used to compute which columns
to use, how to instantiate the model, and how to populate the links
between the objects.
The actual creation of the objects is done in populate() method. This
method gets row and from_obj as input and populates the select_related()
model instance.
"""
def __init__(self, klass_info, select, db):
self.db = db
# Pre-compute needed attributes. The attributes are:
# - model_cls: the possibly deferred model class to instantiate
# - either:
# - cols_start, cols_end: usually the columns in the row are
# in the same order model_cls.__init__ expects them, so we
# can instantiate by model_cls(*row[cols_start:cols_end])
# - reorder_for_init: When select_related descends to a child
# class, then we want to reuse the already selected parent
# data. However, in this case the parent data isn't necessarily
# in the same order that Model.__init__ expects it to be, so
# we have to reorder the parent data. The reorder_for_init
# attribute contains a function used to reorder the field data
# in the order __init__ expects it.
# - pk_idx: the index of the primary key field in the reordered
# model data. Used to check if a related object exists at all.
# - init_list: the field attnames fetched from the database. For
# deferred models this isn't the same as all attnames of the
# model's fields.
# - related_populators: a list of RelatedPopulator instances if
# select_related() descends to related models from this model.
# - local_setter, remote_setter: Methods to set cached values on
# the object being populated and on the remote object. Usually
# these are Field.set_cached_value() methods.
select_fields = klass_info['select_fields']
from_parent = klass_info['from_parent']
if not from_parent:
self.cols_start = select_fields[0]
self.cols_end = select_fields[-1] + 1
self.init_list = [
f[0].target.attname for f in select[self.cols_start:self.cols_end]
]
self.reorder_for_init = None
else:
attname_indexes = {select[idx][0].target.attname: idx for idx in select_fields}
model_init_attnames = (f.attname for f in klass_info['model']._meta.concrete_fields)
self.init_list = [attname for attname in model_init_attnames if attname in attname_indexes]
self.reorder_for_init = operator.itemgetter(*[attname_indexes[attname] for attname in self.init_list])
self.model_cls = klass_info['model']
self.pk_idx = self.init_list.index(self.model_cls._meta.pk.attname)
self.related_populators = get_related_populators(klass_info, select, self.db)
self.local_setter = klass_info['local_setter']
self.remote_setter = klass_info['remote_setter']
def populate(self, row, from_obj):
if self.reorder_for_init:
obj_data = self.reorder_for_init(row)
else:
obj_data = row[self.cols_start:self.cols_end]
if obj_data[self.pk_idx] is None:
obj = None
else:
obj = self.model_cls.from_db(self.db, self.init_list, obj_data)
for rel_iter in self.related_populators:
rel_iter.populate(row, obj)
self.local_setter(from_obj, obj)
if obj is not None:
self.remote_setter(obj, from_obj)
def get_related_populators(klass_info, select, db):
iterators = []
related_klass_infos = klass_info.get('related_klass_infos', [])
for rel_klass_info in related_klass_infos:
rel_cls = RelatedPopulator(rel_klass_info, select, db)
iterators.append(rel_cls)
return iterators
|
fc8aa5fe5f6485f4e3aa080f42ad19862302fba603083a680c92cb99f4cb0f63 | import bisect
import copy
import inspect
from collections import defaultdict
from django.apps import apps
from django.conf import settings
from django.core.exceptions import FieldDoesNotExist, ImproperlyConfigured
from django.db import connections
from django.db.models import AutoField, Manager, OrderWrt, UniqueConstraint
from django.db.models.query_utils import PathInfo
from django.utils.datastructures import ImmutableList, OrderedSet
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from django.utils.text import camel_case_to_spaces, format_lazy
from django.utils.translation import override
PROXY_PARENTS = object()
EMPTY_RELATION_TREE = ()
IMMUTABLE_WARNING = (
"The return type of '%s' should never be mutated. If you want to manipulate this list "
"for your own use, make a copy first."
)
DEFAULT_NAMES = (
'verbose_name', 'verbose_name_plural', 'db_table', 'ordering',
'unique_together', 'permissions', 'get_latest_by', 'order_with_respect_to',
'app_label', 'db_tablespace', 'abstract', 'managed', 'proxy', 'swappable',
'auto_created', 'index_together', 'apps', 'default_permissions',
'select_on_save', 'default_related_name', 'required_db_features',
'required_db_vendor', 'base_manager_name', 'default_manager_name',
'indexes', 'constraints',
)
def normalize_together(option_together):
"""
option_together can be either a tuple of tuples, or a single
tuple of two strings. Normalize it to a tuple of tuples, so that
calling code can uniformly expect that.
"""
try:
if not option_together:
return ()
if not isinstance(option_together, (tuple, list)):
raise TypeError
first_element = option_together[0]
if not isinstance(first_element, (tuple, list)):
option_together = (option_together,)
# Normalize everything to tuples
return tuple(tuple(ot) for ot in option_together)
except TypeError:
# If the value of option_together isn't valid, return it
# verbatim; this will be picked up by the check framework later.
return option_together
def make_immutable_fields_list(name, data):
return ImmutableList(data, warning=IMMUTABLE_WARNING % name)
class Options:
FORWARD_PROPERTIES = {
'fields', 'many_to_many', 'concrete_fields', 'local_concrete_fields',
'_forward_fields_map', 'managers', 'managers_map', 'base_manager',
'default_manager',
}
REVERSE_PROPERTIES = {'related_objects', 'fields_map', '_relation_tree'}
default_apps = apps
def __init__(self, meta, app_label=None):
self._get_fields_cache = {}
self.local_fields = []
self.local_many_to_many = []
self.private_fields = []
self.local_managers = []
self.base_manager_name = None
self.default_manager_name = None
self.model_name = None
self.verbose_name = None
self.verbose_name_plural = None
self.db_table = ''
self.ordering = []
self._ordering_clash = False
self.indexes = []
self.constraints = []
self.unique_together = []
self.index_together = []
self.select_on_save = False
self.default_permissions = ('add', 'change', 'delete', 'view')
self.permissions = []
self.object_name = None
self.app_label = app_label
self.get_latest_by = None
self.order_with_respect_to = None
self.db_tablespace = settings.DEFAULT_TABLESPACE
self.required_db_features = []
self.required_db_vendor = None
self.meta = meta
self.pk = None
self.auto_field = None
self.abstract = False
self.managed = True
self.proxy = False
# For any class that is a proxy (including automatically created
# classes for deferred object loading), proxy_for_model tells us
# which class this model is proxying. Note that proxy_for_model
# can create a chain of proxy models. For non-proxy models, the
# variable is always None.
self.proxy_for_model = None
# For any non-abstract class, the concrete class is the model
# in the end of the proxy_for_model chain. In particular, for
# concrete models, the concrete_model is always the class itself.
self.concrete_model = None
self.swappable = None
self.parents = {}
self.auto_created = False
# List of all lookups defined in ForeignKey 'limit_choices_to' options
# from *other* models. Needed for some admin checks. Internal use only.
self.related_fkey_lookups = []
# A custom app registry to use, if you're making a separate model set.
self.apps = self.default_apps
self.default_related_name = None
@property
def label(self):
return '%s.%s' % (self.app_label, self.object_name)
@property
def label_lower(self):
return '%s.%s' % (self.app_label, self.model_name)
@property
def app_config(self):
# Don't go through get_app_config to avoid triggering imports.
return self.apps.app_configs.get(self.app_label)
def contribute_to_class(self, cls, name):
from django.db import connection
from django.db.backends.utils import truncate_name
cls._meta = self
self.model = cls
# First, construct the default values for these options.
self.object_name = cls.__name__
self.model_name = self.object_name.lower()
self.verbose_name = camel_case_to_spaces(self.object_name)
# Store the original user-defined values for each option,
# for use when serializing the model definition
self.original_attrs = {}
# Next, apply any overridden values from 'class Meta'.
if self.meta:
meta_attrs = self.meta.__dict__.copy()
for name in self.meta.__dict__:
# Ignore any private attributes that Django doesn't care about.
# NOTE: We can't modify a dictionary's contents while looping
# over it, so we loop over the *original* dictionary instead.
if name.startswith('_'):
del meta_attrs[name]
for attr_name in DEFAULT_NAMES:
if attr_name in meta_attrs:
setattr(self, attr_name, meta_attrs.pop(attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
elif hasattr(self.meta, attr_name):
setattr(self, attr_name, getattr(self.meta, attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
self.unique_together = normalize_together(self.unique_together)
self.index_together = normalize_together(self.index_together)
# App label/class name interpolation for names of constraints and
# indexes.
if not getattr(cls._meta, 'abstract', False):
for attr_name in {'constraints', 'indexes'}:
objs = getattr(self, attr_name, [])
setattr(self, attr_name, self._format_names_with_class(cls, objs))
# verbose_name_plural is a special case because it uses a 's'
# by default.
if self.verbose_name_plural is None:
self.verbose_name_plural = format_lazy('{}s', self.verbose_name)
# order_with_respect_and ordering are mutually exclusive.
self._ordering_clash = bool(self.ordering and self.order_with_respect_to)
# Any leftover attributes must be invalid.
if meta_attrs != {}:
raise TypeError("'class Meta' got invalid attribute(s): %s" % ','.join(meta_attrs))
else:
self.verbose_name_plural = format_lazy('{}s', self.verbose_name)
del self.meta
# If the db_table wasn't provided, use the app_label + model_name.
if not self.db_table:
self.db_table = "%s_%s" % (self.app_label, self.model_name)
self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
def _format_names_with_class(self, cls, objs):
"""App label/class name interpolation for object names."""
new_objs = []
for obj in objs:
obj = obj.clone()
obj.name = obj.name % {
'app_label': cls._meta.app_label.lower(),
'class': cls.__name__.lower(),
}
new_objs.append(obj)
return new_objs
def _get_default_pk_class(self):
pk_class_path = getattr(
self.app_config,
'default_auto_field',
settings.DEFAULT_AUTO_FIELD,
)
if self.app_config and self.app_config._is_default_auto_field_overridden:
app_config_class = type(self.app_config)
source = (
f'{app_config_class.__module__}.'
f'{app_config_class.__qualname__}.default_auto_field'
)
else:
source = 'DEFAULT_AUTO_FIELD'
if not pk_class_path:
raise ImproperlyConfigured(f'{source} must not be empty.')
try:
pk_class = import_string(pk_class_path)
except ImportError as e:
msg = (
f"{source} refers to the module '{pk_class_path}' that could "
f"not be imported."
)
raise ImproperlyConfigured(msg) from e
if not issubclass(pk_class, AutoField):
raise ValueError(
f"Primary key '{pk_class_path}' referred by {source} must "
f"subclass AutoField."
)
return pk_class
def _prepare(self, model):
if self.order_with_respect_to:
# The app registry will not be ready at this point, so we cannot
# use get_field().
query = self.order_with_respect_to
try:
self.order_with_respect_to = next(
f for f in self._get_fields(reverse=False)
if f.name == query or f.attname == query
)
except StopIteration:
raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, query))
self.ordering = ('_order',)
if not any(isinstance(field, OrderWrt) for field in model._meta.local_fields):
model.add_to_class('_order', OrderWrt())
else:
self.order_with_respect_to = None
if self.pk is None:
if self.parents:
# Promote the first parent link in lieu of adding yet another
# field.
field = next(iter(self.parents.values()))
# Look for a local field with the same name as the
# first parent link. If a local field has already been
# created, use it instead of promoting the parent
already_created = [fld for fld in self.local_fields if fld.name == field.name]
if already_created:
field = already_created[0]
field.primary_key = True
self.setup_pk(field)
else:
pk_class = self._get_default_pk_class()
auto = pk_class(verbose_name='ID', primary_key=True, auto_created=True)
model.add_to_class('id', auto)
def add_manager(self, manager):
self.local_managers.append(manager)
self._expire_cache()
def add_field(self, field, private=False):
# Insert the given field in the order in which it was created, using
# the "creation_counter" attribute of the field.
# Move many-to-many related fields from self.fields into
# self.many_to_many.
if private:
self.private_fields.append(field)
elif field.is_relation and field.many_to_many:
bisect.insort(self.local_many_to_many, field)
else:
bisect.insort(self.local_fields, field)
self.setup_pk(field)
# If the field being added is a relation to another known field,
# expire the cache on this field and the forward cache on the field
# being referenced, because there will be new relationships in the
# cache. Otherwise, expire the cache of references *to* this field.
# The mechanism for getting at the related model is slightly odd -
# ideally, we'd just ask for field.related_model. However, related_model
# is a cached property, and all the models haven't been loaded yet, so
# we need to make sure we don't cache a string reference.
if field.is_relation and hasattr(field.remote_field, 'model') and field.remote_field.model:
try:
field.remote_field.model._meta._expire_cache(forward=False)
except AttributeError:
pass
self._expire_cache()
else:
self._expire_cache(reverse=False)
def setup_pk(self, field):
if not self.pk and field.primary_key:
self.pk = field
field.serialize = False
def setup_proxy(self, target):
"""
Do the internal setup so that the current model is a proxy for
"target".
"""
self.pk = target._meta.pk
self.proxy_for_model = target
self.db_table = target._meta.db_table
def __repr__(self):
return '<Options for %s>' % self.object_name
def __str__(self):
return self.label_lower
def can_migrate(self, connection):
"""
Return True if the model can/should be migrated on the `connection`.
`connection` can be either a real connection or a connection alias.
"""
if self.proxy or self.swapped or not self.managed:
return False
if isinstance(connection, str):
connection = connections[connection]
if self.required_db_vendor:
return self.required_db_vendor == connection.vendor
if self.required_db_features:
return all(getattr(connection.features, feat, False)
for feat in self.required_db_features)
return True
@property
def verbose_name_raw(self):
"""Return the untranslated verbose name."""
with override(None):
return str(self.verbose_name)
@property
def swapped(self):
"""
Has this model been swapped out for another? If so, return the model
name of the replacement; otherwise, return None.
For historical reasons, model name lookups using get_model() are
case insensitive, so we make sure we are case insensitive here.
"""
if self.swappable:
swapped_for = getattr(settings, self.swappable, None)
if swapped_for:
try:
swapped_label, swapped_object = swapped_for.split('.')
except ValueError:
# setting not in the format app_label.model_name
# raising ImproperlyConfigured here causes problems with
# test cleanup code - instead it is raised in get_user_model
# or as part of validation.
return swapped_for
if '%s.%s' % (swapped_label, swapped_object.lower()) != self.label_lower:
return swapped_for
return None
@cached_property
def managers(self):
managers = []
seen_managers = set()
bases = (b for b in self.model.mro() if hasattr(b, '_meta'))
for depth, base in enumerate(bases):
for manager in base._meta.local_managers:
if manager.name in seen_managers:
continue
manager = copy.copy(manager)
manager.model = self.model
seen_managers.add(manager.name)
managers.append((depth, manager.creation_counter, manager))
return make_immutable_fields_list(
"managers",
(m[2] for m in sorted(managers)),
)
@cached_property
def managers_map(self):
return {manager.name: manager for manager in self.managers}
@cached_property
def base_manager(self):
base_manager_name = self.base_manager_name
if not base_manager_name:
# Get the first parent's base_manager_name if there's one.
for parent in self.model.mro()[1:]:
if hasattr(parent, '_meta'):
if parent._base_manager.name != '_base_manager':
base_manager_name = parent._base_manager.name
break
if base_manager_name:
try:
return self.managers_map[base_manager_name]
except KeyError:
raise ValueError(
"%s has no manager named %r" % (
self.object_name,
base_manager_name,
)
)
manager = Manager()
manager.name = '_base_manager'
manager.model = self.model
manager.auto_created = True
return manager
@cached_property
def default_manager(self):
default_manager_name = self.default_manager_name
if not default_manager_name and not self.local_managers:
# Get the first parent's default_manager_name if there's one.
for parent in self.model.mro()[1:]:
if hasattr(parent, '_meta'):
default_manager_name = parent._meta.default_manager_name
break
if default_manager_name:
try:
return self.managers_map[default_manager_name]
except KeyError:
raise ValueError(
"%s has no manager named %r" % (
self.object_name,
default_manager_name,
)
)
if self.managers:
return self.managers[0]
@cached_property
def fields(self):
"""
Return a list of all forward fields on the model and its parents,
excluding ManyToManyFields.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
# For legacy reasons, the fields property should only contain forward
# fields that are not private or with a m2m cardinality. Therefore we
# pass these three filters as filters to the generator.
# The third lambda is a longwinded way of checking f.related_model - we don't
# use that property directly because related_model is a cached property,
# and all the models may not have been loaded yet; we don't want to cache
# the string reference to the related_model.
def is_not_an_m2m_field(f):
return not (f.is_relation and f.many_to_many)
def is_not_a_generic_relation(f):
return not (f.is_relation and f.one_to_many)
def is_not_a_generic_foreign_key(f):
return not (
f.is_relation and f.many_to_one and not (hasattr(f.remote_field, 'model') and f.remote_field.model)
)
return make_immutable_fields_list(
"fields",
(f for f in self._get_fields(reverse=False)
if is_not_an_m2m_field(f) and is_not_a_generic_relation(f) and is_not_a_generic_foreign_key(f))
)
@cached_property
def concrete_fields(self):
"""
Return a list of all concrete fields on the model and its parents.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
return make_immutable_fields_list(
"concrete_fields", (f for f in self.fields if f.concrete)
)
@cached_property
def local_concrete_fields(self):
"""
Return a list of all concrete fields on the model.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
return make_immutable_fields_list(
"local_concrete_fields", (f for f in self.local_fields if f.concrete)
)
@cached_property
def many_to_many(self):
"""
Return a list of all many to many fields on the model and its parents.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this list.
"""
return make_immutable_fields_list(
"many_to_many",
(f for f in self._get_fields(reverse=False) if f.is_relation and f.many_to_many)
)
@cached_property
def related_objects(self):
"""
Return all related objects pointing to the current model. The related
objects can come from a one-to-one, one-to-many, or many-to-many field
relation type.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
all_related_fields = self._get_fields(forward=False, reverse=True, include_hidden=True)
return make_immutable_fields_list(
"related_objects",
(obj for obj in all_related_fields if not obj.hidden or obj.field.many_to_many)
)
@cached_property
def _forward_fields_map(self):
res = {}
fields = self._get_fields(reverse=False)
for field in fields:
res[field.name] = field
# Due to the way Django's internals work, get_field() should also
# be able to fetch a field by attname. In the case of a concrete
# field with relation, includes the *_id name too
try:
res[field.attname] = field
except AttributeError:
pass
return res
@cached_property
def fields_map(self):
res = {}
fields = self._get_fields(forward=False, include_hidden=True)
for field in fields:
res[field.name] = field
# Due to the way Django's internals work, get_field() should also
# be able to fetch a field by attname. In the case of a concrete
# field with relation, includes the *_id name too
try:
res[field.attname] = field
except AttributeError:
pass
return res
def get_field(self, field_name):
"""
Return a field instance given the name of a forward or reverse field.
"""
try:
# In order to avoid premature loading of the relation tree
# (expensive) we prefer checking if the field is a forward field.
return self._forward_fields_map[field_name]
except KeyError:
# If the app registry is not ready, reverse fields are
# unavailable, therefore we throw a FieldDoesNotExist exception.
if not self.apps.models_ready:
raise FieldDoesNotExist(
"%s has no field named '%s'. The app cache isn't ready yet, "
"so if this is an auto-created related field, it won't "
"be available yet." % (self.object_name, field_name)
)
try:
# Retrieve field instance by name from cached or just-computed
# field map.
return self.fields_map[field_name]
except KeyError:
raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))
def get_base_chain(self, model):
"""
Return a list of parent classes leading to `model` (ordered from
closest to most distant ancestor). This has to handle the case where
`model` is a grandparent or even more distant relation.
"""
if not self.parents:
return []
if model in self.parents:
return [model]
for parent in self.parents:
res = parent._meta.get_base_chain(model)
if res:
res.insert(0, parent)
return res
return []
def get_parent_list(self):
"""
Return all the ancestors of this model as a list ordered by MRO.
Useful for determining if something is an ancestor, regardless of lineage.
"""
result = OrderedSet(self.parents)
for parent in self.parents:
for ancestor in parent._meta.get_parent_list():
result.add(ancestor)
return list(result)
def get_ancestor_link(self, ancestor):
"""
Return the field on the current model which points to the given
"ancestor". This is possible an indirect link (a pointer to a parent
model, which points, eventually, to the ancestor). Used when
constructing table joins for model inheritance.
Return None if the model isn't an ancestor of this one.
"""
if ancestor in self.parents:
return self.parents[ancestor]
for parent in self.parents:
# Tries to get a link field from the immediate parent
parent_link = parent._meta.get_ancestor_link(ancestor)
if parent_link:
# In case of a proxied model, the first link
# of the chain to the ancestor is that parent
# links
return self.parents[parent] or parent_link
def get_path_to_parent(self, parent):
"""
Return a list of PathInfos containing the path from the current
model to the parent model, or an empty list if parent is not a
parent of the current model.
"""
if self.model is parent:
return []
# Skip the chain of proxy to the concrete proxied model.
proxied_model = self.concrete_model
path = []
opts = self
for int_model in self.get_base_chain(parent):
if int_model is proxied_model:
opts = int_model._meta
else:
final_field = opts.parents[int_model]
targets = (final_field.remote_field.get_related_field(),)
opts = int_model._meta
path.append(PathInfo(
from_opts=final_field.model._meta,
to_opts=opts,
target_fields=targets,
join_field=final_field,
m2m=False,
direct=True,
filtered_relation=None,
))
return path
def get_path_from_parent(self, parent):
"""
Return a list of PathInfos containing the path from the parent
model to the current model, or an empty list if parent is not a
parent of the current model.
"""
if self.model is parent:
return []
model = self.concrete_model
# Get a reversed base chain including both the current and parent
# models.
chain = model._meta.get_base_chain(parent)
chain.reverse()
chain.append(model)
# Construct a list of the PathInfos between models in chain.
path = []
for i, ancestor in enumerate(chain[:-1]):
child = chain[i + 1]
link = child._meta.get_ancestor_link(ancestor)
path.extend(link.reverse_path_infos)
return path
def _populate_directed_relation_graph(self):
"""
This method is used by each model to find its reverse objects. As this
method is very expensive and is accessed frequently (it looks up every
field in a model, in every app), it is computed on first access and then
is set as a property on every model.
"""
related_objects_graph = defaultdict(list)
all_models = self.apps.get_models(include_auto_created=True)
for model in all_models:
opts = model._meta
# Abstract model's fields are copied to child models, hence we will
# see the fields from the child models.
if opts.abstract:
continue
fields_with_relations = (
f for f in opts._get_fields(reverse=False, include_parents=False)
if f.is_relation and f.related_model is not None
)
for f in fields_with_relations:
if not isinstance(f.remote_field.model, str):
remote_label = f.remote_field.model._meta.concrete_model._meta.label
related_objects_graph[remote_label].append(f)
for model in all_models:
# Set the relation_tree using the internal __dict__. In this way
# we avoid calling the cached property. In attribute lookup,
# __dict__ takes precedence over a data descriptor (such as
# @cached_property). This means that the _meta._relation_tree is
# only called if related_objects is not in __dict__.
related_objects = related_objects_graph[model._meta.concrete_model._meta.label]
model._meta.__dict__['_relation_tree'] = related_objects
# It seems it is possible that self is not in all_models, so guard
# against that with default for get().
return self.__dict__.get('_relation_tree', EMPTY_RELATION_TREE)
@cached_property
def _relation_tree(self):
return self._populate_directed_relation_graph()
def _expire_cache(self, forward=True, reverse=True):
# This method is usually called by apps.cache_clear(), when the
# registry is finalized, or when a new field is added.
if forward:
for cache_key in self.FORWARD_PROPERTIES:
if cache_key in self.__dict__:
delattr(self, cache_key)
if reverse and not self.abstract:
for cache_key in self.REVERSE_PROPERTIES:
if cache_key in self.__dict__:
delattr(self, cache_key)
self._get_fields_cache = {}
def get_fields(self, include_parents=True, include_hidden=False):
"""
Return a list of fields associated to the model. By default, include
forward and reverse fields, fields derived from inheritance, but not
hidden fields. The returned fields can be changed using the parameters:
- include_parents: include fields derived from inheritance
- include_hidden: include fields that have a related_name that
starts with a "+"
"""
if include_parents is False:
include_parents = PROXY_PARENTS
return self._get_fields(include_parents=include_parents, include_hidden=include_hidden)
def _get_fields(self, forward=True, reverse=True, include_parents=True, include_hidden=False,
seen_models=None):
"""
Internal helper function to return fields of the model.
* If forward=True, then fields defined on this model are returned.
* If reverse=True, then relations pointing to this model are returned.
* If include_hidden=True, then fields with is_hidden=True are returned.
* The include_parents argument toggles if fields from parent models
should be included. It has three values: True, False, and
PROXY_PARENTS. When set to PROXY_PARENTS, the call will return all
fields defined for the current model or any of its parents in the
parent chain to the model's concrete model.
"""
if include_parents not in (True, False, PROXY_PARENTS):
raise TypeError("Invalid argument for include_parents: %s" % (include_parents,))
# This helper function is used to allow recursion in ``get_fields()``
# implementation and to provide a fast way for Django's internals to
# access specific subsets of fields.
# We must keep track of which models we have already seen. Otherwise we
# could include the same field multiple times from different models.
topmost_call = seen_models is None
if topmost_call:
seen_models = set()
seen_models.add(self.model)
# Creates a cache key composed of all arguments
cache_key = (forward, reverse, include_parents, include_hidden, topmost_call)
try:
# In order to avoid list manipulation. Always return a shallow copy
# of the results.
return self._get_fields_cache[cache_key]
except KeyError:
pass
fields = []
# Recursively call _get_fields() on each parent, with the same
# options provided in this call.
if include_parents is not False:
for parent in self.parents:
# In diamond inheritance it is possible that we see the same
# model from two different routes. In that case, avoid adding
# fields from the same parent again.
if parent in seen_models:
continue
if (parent._meta.concrete_model != self.concrete_model and
include_parents == PROXY_PARENTS):
continue
for obj in parent._meta._get_fields(
forward=forward, reverse=reverse, include_parents=include_parents,
include_hidden=include_hidden, seen_models=seen_models):
if not getattr(obj, 'parent_link', False) or obj.model == self.concrete_model:
fields.append(obj)
if reverse and not self.proxy:
# Tree is computed once and cached until the app cache is expired.
# It is composed of a list of fields pointing to the current model
# from other models.
all_fields = self._relation_tree
for field in all_fields:
# If hidden fields should be included or the relation is not
# intentionally hidden, add to the fields dict.
if include_hidden or not field.remote_field.hidden:
fields.append(field.remote_field)
if forward:
fields += self.local_fields
fields += self.local_many_to_many
# Private fields are recopied to each child model, and they get a
# different model as field.model in each child. Hence we have to
# add the private fields separately from the topmost call. If we
# did this recursively similar to local_fields, we would get field
# instances with field.model != self.model.
if topmost_call:
fields += self.private_fields
# In order to avoid list manipulation. Always
# return a shallow copy of the results
fields = make_immutable_fields_list("get_fields()", fields)
# Store result into cache for later access
self._get_fields_cache[cache_key] = fields
return fields
@cached_property
def total_unique_constraints(self):
"""
Return a list of total unique constraints. Useful for determining set
of fields guaranteed to be unique for all rows.
"""
return [
constraint
for constraint in self.constraints
if (
isinstance(constraint, UniqueConstraint) and
constraint.condition is None and
not constraint.contains_expressions
)
]
@cached_property
def _property_names(self):
"""Return a set of the names of the properties defined on the model."""
names = []
for name in dir(self.model):
attr = inspect.getattr_static(self.model, name)
if isinstance(attr, property):
names.append(name)
return frozenset(names)
@cached_property
def db_returning_fields(self):
"""
Private API intended only to be used by Django itself.
Fields to be returned after a database insert.
"""
return [
field for field in self._get_fields(forward=True, reverse=False, include_parents=PROXY_PARENTS)
if getattr(field, 'db_returning', False)
]
|
5217c5976fa8ee17c8439fbe5a7115538307c73dc7f011f5f754e2783eb336af | import copy
import inspect
import warnings
from functools import partialmethod
from itertools import chain
import django
from django.apps import apps
from django.conf import settings
from django.core import checks
from django.core.exceptions import (
NON_FIELD_ERRORS, FieldDoesNotExist, FieldError, MultipleObjectsReturned,
ObjectDoesNotExist, ValidationError,
)
from django.db import (
DEFAULT_DB_ALIAS, DJANGO_VERSION_PICKLE_KEY, DatabaseError, connection,
connections, router, transaction,
)
from django.db.models import (
NOT_PROVIDED, ExpressionWrapper, IntegerField, Max, Value,
)
from django.db.models.constants import LOOKUP_SEP
from django.db.models.constraints import CheckConstraint, UniqueConstraint
from django.db.models.deletion import CASCADE, Collector
from django.db.models.fields.related import (
ForeignObjectRel, OneToOneField, lazy_related_operation, resolve_relation,
)
from django.db.models.functions import Coalesce
from django.db.models.manager import Manager
from django.db.models.options import Options
from django.db.models.query import F, Q
from django.db.models.signals import (
class_prepared, post_init, post_save, pre_init, pre_save,
)
from django.db.models.utils import make_model_tuple
from django.utils.encoding import force_str
from django.utils.hashable import make_hashable
from django.utils.text import capfirst, get_text_list
from django.utils.translation import gettext_lazy as _
class Deferred:
def __repr__(self):
return '<Deferred field>'
def __str__(self):
return '<Deferred field>'
DEFERRED = Deferred()
def subclass_exception(name, bases, module, attached_to):
"""
Create exception subclass. Used by ModelBase below.
The exception is created in a way that allows it to be pickled, assuming
that the returned exception class will be added as an attribute to the
'attached_to' class.
"""
return type(name, bases, {
'__module__': module,
'__qualname__': '%s.%s' % (attached_to.__qualname__, name),
})
def _has_contribute_to_class(value):
# Only call contribute_to_class() if it's bound.
return not inspect.isclass(value) and hasattr(value, 'contribute_to_class')
class ModelBase(type):
"""Metaclass for all models."""
def __new__(cls, name, bases, attrs, **kwargs):
super_new = super().__new__
# Also ensure initialization is only performed for subclasses of Model
# (excluding Model class itself).
parents = [b for b in bases if isinstance(b, ModelBase)]
if not parents:
return super_new(cls, name, bases, attrs)
# Create the class.
module = attrs.pop('__module__')
new_attrs = {'__module__': module}
classcell = attrs.pop('__classcell__', None)
if classcell is not None:
new_attrs['__classcell__'] = classcell
attr_meta = attrs.pop('Meta', None)
# Pass all attrs without a (Django-specific) contribute_to_class()
# method to type.__new__() so that they're properly initialized
# (i.e. __set_name__()).
contributable_attrs = {}
for obj_name, obj in attrs.items():
if _has_contribute_to_class(obj):
contributable_attrs[obj_name] = obj
else:
new_attrs[obj_name] = obj
new_class = super_new(cls, name, bases, new_attrs, **kwargs)
abstract = getattr(attr_meta, 'abstract', False)
meta = attr_meta or getattr(new_class, 'Meta', None)
base_meta = getattr(new_class, '_meta', None)
app_label = None
# Look for an application configuration to attach the model to.
app_config = apps.get_containing_app_config(module)
if getattr(meta, 'app_label', None) is None:
if app_config is None:
if not abstract:
raise RuntimeError(
"Model class %s.%s doesn't declare an explicit "
"app_label and isn't in an application in "
"INSTALLED_APPS." % (module, name)
)
else:
app_label = app_config.label
new_class.add_to_class('_meta', Options(meta, app_label))
if not abstract:
new_class.add_to_class(
'DoesNotExist',
subclass_exception(
'DoesNotExist',
tuple(
x.DoesNotExist for x in parents if hasattr(x, '_meta') and not x._meta.abstract
) or (ObjectDoesNotExist,),
module,
attached_to=new_class))
new_class.add_to_class(
'MultipleObjectsReturned',
subclass_exception(
'MultipleObjectsReturned',
tuple(
x.MultipleObjectsReturned for x in parents if hasattr(x, '_meta') and not x._meta.abstract
) or (MultipleObjectsReturned,),
module,
attached_to=new_class))
if base_meta and not base_meta.abstract:
# Non-abstract child classes inherit some attributes from their
# non-abstract parent (unless an ABC comes before it in the
# method resolution order).
if not hasattr(meta, 'ordering'):
new_class._meta.ordering = base_meta.ordering
if not hasattr(meta, 'get_latest_by'):
new_class._meta.get_latest_by = base_meta.get_latest_by
is_proxy = new_class._meta.proxy
# If the model is a proxy, ensure that the base class
# hasn't been swapped out.
if is_proxy and base_meta and base_meta.swapped:
raise TypeError("%s cannot proxy the swapped model '%s'." % (name, base_meta.swapped))
# Add remaining attributes (those with a contribute_to_class() method)
# to the class.
for obj_name, obj in contributable_attrs.items():
new_class.add_to_class(obj_name, obj)
# All the fields of any type declared on this model
new_fields = chain(
new_class._meta.local_fields,
new_class._meta.local_many_to_many,
new_class._meta.private_fields
)
field_names = {f.name for f in new_fields}
# Basic setup for proxy models.
if is_proxy:
base = None
for parent in [kls for kls in parents if hasattr(kls, '_meta')]:
if parent._meta.abstract:
if parent._meta.fields:
raise TypeError(
"Abstract base class containing model fields not "
"permitted for proxy model '%s'." % name
)
else:
continue
if base is None:
base = parent
elif parent._meta.concrete_model is not base._meta.concrete_model:
raise TypeError("Proxy model '%s' has more than one non-abstract model base class." % name)
if base is None:
raise TypeError("Proxy model '%s' has no non-abstract model base class." % name)
new_class._meta.setup_proxy(base)
new_class._meta.concrete_model = base._meta.concrete_model
else:
new_class._meta.concrete_model = new_class
# Collect the parent links for multi-table inheritance.
parent_links = {}
for base in reversed([new_class] + parents):
# Conceptually equivalent to `if base is Model`.
if not hasattr(base, '_meta'):
continue
# Skip concrete parent classes.
if base != new_class and not base._meta.abstract:
continue
# Locate OneToOneField instances.
for field in base._meta.local_fields:
if isinstance(field, OneToOneField) and field.remote_field.parent_link:
related = resolve_relation(new_class, field.remote_field.model)
parent_links[make_model_tuple(related)] = field
# Track fields inherited from base models.
inherited_attributes = set()
# Do the appropriate setup for any model parents.
for base in new_class.mro():
if base not in parents or not hasattr(base, '_meta'):
# Things without _meta aren't functional models, so they're
# uninteresting parents.
inherited_attributes.update(base.__dict__)
continue
parent_fields = base._meta.local_fields + base._meta.local_many_to_many
if not base._meta.abstract:
# Check for clashes between locally declared fields and those
# on the base classes.
for field in parent_fields:
if field.name in field_names:
raise FieldError(
'Local field %r in class %r clashes with field of '
'the same name from base class %r.' % (
field.name,
name,
base.__name__,
)
)
else:
inherited_attributes.add(field.name)
# Concrete classes...
base = base._meta.concrete_model
base_key = make_model_tuple(base)
if base_key in parent_links:
field = parent_links[base_key]
elif not is_proxy:
attr_name = '%s_ptr' % base._meta.model_name
field = OneToOneField(
base,
on_delete=CASCADE,
name=attr_name,
auto_created=True,
parent_link=True,
)
if attr_name in field_names:
raise FieldError(
"Auto-generated field '%s' in class %r for "
"parent_link to base class %r clashes with "
"declared field of the same name." % (
attr_name,
name,
base.__name__,
)
)
# Only add the ptr field if it's not already present;
# e.g. migrations will already have it specified
if not hasattr(new_class, attr_name):
new_class.add_to_class(attr_name, field)
else:
field = None
new_class._meta.parents[base] = field
else:
base_parents = base._meta.parents.copy()
# Add fields from abstract base class if it wasn't overridden.
for field in parent_fields:
if (field.name not in field_names and
field.name not in new_class.__dict__ and
field.name not in inherited_attributes):
new_field = copy.deepcopy(field)
new_class.add_to_class(field.name, new_field)
# Replace parent links defined on this base by the new
# field. It will be appropriately resolved if required.
if field.one_to_one:
for parent, parent_link in base_parents.items():
if field == parent_link:
base_parents[parent] = new_field
# Pass any non-abstract parent classes onto child.
new_class._meta.parents.update(base_parents)
# Inherit private fields (like GenericForeignKey) from the parent
# class
for field in base._meta.private_fields:
if field.name in field_names:
if not base._meta.abstract:
raise FieldError(
'Local field %r in class %r clashes with field of '
'the same name from base class %r.' % (
field.name,
name,
base.__name__,
)
)
else:
field = copy.deepcopy(field)
if not base._meta.abstract:
field.mti_inherited = True
new_class.add_to_class(field.name, field)
# Copy indexes so that index names are unique when models extend an
# abstract model.
new_class._meta.indexes = [copy.deepcopy(idx) for idx in new_class._meta.indexes]
if abstract:
# Abstract base models can't be instantiated and don't appear in
# the list of models for an app. We do the final setup for them a
# little differently from normal models.
attr_meta.abstract = False
new_class.Meta = attr_meta
return new_class
new_class._prepare()
new_class._meta.apps.register_model(new_class._meta.app_label, new_class)
return new_class
def add_to_class(cls, name, value):
if _has_contribute_to_class(value):
value.contribute_to_class(cls, name)
else:
setattr(cls, name, value)
def _prepare(cls):
"""Create some methods once self._meta has been populated."""
opts = cls._meta
opts._prepare(cls)
if opts.order_with_respect_to:
cls.get_next_in_order = partialmethod(cls._get_next_or_previous_in_order, is_next=True)
cls.get_previous_in_order = partialmethod(cls._get_next_or_previous_in_order, is_next=False)
# Defer creating accessors on the foreign class until it has been
# created and registered. If remote_field is None, we're ordering
# with respect to a GenericForeignKey and don't know what the
# foreign class is - we'll add those accessors later in
# contribute_to_class().
if opts.order_with_respect_to.remote_field:
wrt = opts.order_with_respect_to
remote = wrt.remote_field.model
lazy_related_operation(make_foreign_order_accessors, cls, remote)
# Give the class a docstring -- its definition.
if cls.__doc__ is None:
cls.__doc__ = "%s(%s)" % (cls.__name__, ", ".join(f.name for f in opts.fields))
get_absolute_url_override = settings.ABSOLUTE_URL_OVERRIDES.get(opts.label_lower)
if get_absolute_url_override:
setattr(cls, 'get_absolute_url', get_absolute_url_override)
if not opts.managers:
if any(f.name == 'objects' for f in opts.fields):
raise ValueError(
"Model %s must specify a custom Manager, because it has a "
"field named 'objects'." % cls.__name__
)
manager = Manager()
manager.auto_created = True
cls.add_to_class('objects', manager)
# Set the name of _meta.indexes. This can't be done in
# Options.contribute_to_class() because fields haven't been added to
# the model at that point.
for index in cls._meta.indexes:
if not index.name:
index.set_name_with_model(cls)
class_prepared.send(sender=cls)
@property
def _base_manager(cls):
return cls._meta.base_manager
@property
def _default_manager(cls):
return cls._meta.default_manager
class ModelStateCacheDescriptor:
"""
Upon first access, replace itself with an empty dictionary on the instance.
"""
def __set_name__(self, owner, name):
self.attribute_name = name
def __get__(self, instance, cls=None):
if instance is None:
return self
res = instance.__dict__[self.attribute_name] = {}
return res
class ModelState:
"""Store model instance state."""
db = None
# If true, uniqueness validation checks will consider this a new, unsaved
# object. Necessary for correct validation of new instances of objects with
# explicit (non-auto) PKs. This impacts validation only; it has no effect
# on the actual save.
adding = True
fields_cache = ModelStateCacheDescriptor()
related_managers_cache = ModelStateCacheDescriptor()
def __getstate__(self):
state = self.__dict__.copy()
if 'fields_cache' in state:
state['fields_cache'] = self.fields_cache.copy()
# Manager instances stored in related_managers_cache won't necessarily
# be deserializable if they were dynamically created via an inner
# scope, e.g. create_forward_many_to_many_manager() and
# create_generic_related_manager().
if 'related_managers_cache' in state:
state['related_managers_cache'] = {}
return state
class Model(metaclass=ModelBase):
def __init__(self, *args, **kwargs):
# Alias some things as locals to avoid repeat global lookups
cls = self.__class__
opts = self._meta
_setattr = setattr
_DEFERRED = DEFERRED
if opts.abstract:
raise TypeError('Abstract models cannot be instantiated.')
pre_init.send(sender=cls, args=args, kwargs=kwargs)
# Set up the storage for instance state
self._state = ModelState()
# There is a rather weird disparity here; if kwargs, it's set, then args
# overrides it. It should be one or the other; don't duplicate the work
# The reason for the kwargs check is that standard iterator passes in by
# args, and instantiation for iteration is 33% faster.
if len(args) > len(opts.concrete_fields):
# Daft, but matches old exception sans the err msg.
raise IndexError("Number of args exceeds number of fields")
if not kwargs:
fields_iter = iter(opts.concrete_fields)
# The ordering of the zip calls matter - zip throws StopIteration
# when an iter throws it. So if the first iter throws it, the second
# is *not* consumed. We rely on this, so don't change the order
# without changing the logic.
for val, field in zip(args, fields_iter):
if val is _DEFERRED:
continue
_setattr(self, field.attname, val)
else:
# Slower, kwargs-ready version.
fields_iter = iter(opts.fields)
for val, field in zip(args, fields_iter):
if val is _DEFERRED:
continue
_setattr(self, field.attname, val)
if kwargs.pop(field.name, NOT_PROVIDED) is not NOT_PROVIDED:
raise TypeError(
f"{cls.__qualname__}() got both positional and "
f"keyword arguments for field '{field.name}'."
)
# Now we're left with the unprocessed fields that *must* come from
# keywords, or default.
for field in fields_iter:
is_related_object = False
# Virtual field
if field.attname not in kwargs and field.column is None:
continue
if kwargs:
if isinstance(field.remote_field, ForeignObjectRel):
try:
# Assume object instance was passed in.
rel_obj = kwargs.pop(field.name)
is_related_object = True
except KeyError:
try:
# Object instance wasn't passed in -- must be an ID.
val = kwargs.pop(field.attname)
except KeyError:
val = field.get_default()
else:
try:
val = kwargs.pop(field.attname)
except KeyError:
# This is done with an exception rather than the
# default argument on pop because we don't want
# get_default() to be evaluated, and then not used.
# Refs #12057.
val = field.get_default()
else:
val = field.get_default()
if is_related_object:
# If we are passed a related instance, set it using the
# field.name instead of field.attname (e.g. "user" instead of
# "user_id") so that the object gets properly cached (and type
# checked) by the RelatedObjectDescriptor.
if rel_obj is not _DEFERRED:
_setattr(self, field.name, rel_obj)
else:
if val is not _DEFERRED:
_setattr(self, field.attname, val)
if kwargs:
property_names = opts._property_names
unexpected = ()
for prop, value in kwargs.items():
# Any remaining kwargs must correspond to properties or virtual
# fields.
if prop in property_names:
if value is not _DEFERRED:
_setattr(self, prop, value)
else:
try:
opts.get_field(prop)
except FieldDoesNotExist:
unexpected += (prop,)
else:
if value is not _DEFERRED:
_setattr(self, prop, value)
if unexpected:
unexpected_names = ', '.join(repr(n) for n in unexpected)
raise TypeError(
f'{cls.__name__}() got unexpected keyword arguments: '
f'{unexpected_names}'
)
super().__init__()
post_init.send(sender=cls, instance=self)
@classmethod
def from_db(cls, db, field_names, values):
if len(values) != len(cls._meta.concrete_fields):
values_iter = iter(values)
values = [
next(values_iter) if f.attname in field_names else DEFERRED
for f in cls._meta.concrete_fields
]
new = cls(*values)
new._state.adding = False
new._state.db = db
return new
def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self)
def __str__(self):
return '%s object (%s)' % (self.__class__.__name__, self.pk)
def __eq__(self, other):
if not isinstance(other, Model):
return NotImplemented
if self._meta.concrete_model != other._meta.concrete_model:
return False
my_pk = self.pk
if my_pk is None:
return self is other
return my_pk == other.pk
def __hash__(self):
if self.pk is None:
raise TypeError("Model instances without primary key value are unhashable")
return hash(self.pk)
def __reduce__(self):
data = self.__getstate__()
data[DJANGO_VERSION_PICKLE_KEY] = django.__version__
class_id = self._meta.app_label, self._meta.object_name
return model_unpickle, (class_id,), data
def __getstate__(self):
"""Hook to allow choosing the attributes to pickle."""
state = self.__dict__.copy()
state['_state'] = copy.copy(state['_state'])
# memoryview cannot be pickled, so cast it to bytes and store
# separately.
_memoryview_attrs = []
for attr, value in state.items():
if isinstance(value, memoryview):
_memoryview_attrs.append((attr, bytes(value)))
if _memoryview_attrs:
state['_memoryview_attrs'] = _memoryview_attrs
for attr, value in _memoryview_attrs:
state.pop(attr)
return state
def __setstate__(self, state):
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
if pickled_version != django.__version__:
warnings.warn(
"Pickled model instance's Django version %s does not "
"match the current version %s."
% (pickled_version, django.__version__),
RuntimeWarning,
stacklevel=2,
)
else:
warnings.warn(
"Pickled model instance's Django version is not specified.",
RuntimeWarning,
stacklevel=2,
)
if '_memoryview_attrs' in state:
for attr, value in state.pop('_memoryview_attrs'):
state[attr] = memoryview(value)
self.__dict__.update(state)
def _get_pk_val(self, meta=None):
meta = meta or self._meta
return getattr(self, meta.pk.attname)
def _set_pk_val(self, value):
for parent_link in self._meta.parents.values():
if parent_link and parent_link != self._meta.pk:
setattr(self, parent_link.target_field.attname, value)
return setattr(self, self._meta.pk.attname, value)
pk = property(_get_pk_val, _set_pk_val)
def get_deferred_fields(self):
"""
Return a set containing names of deferred fields for this instance.
"""
return {
f.attname for f in self._meta.concrete_fields
if f.attname not in self.__dict__
}
def refresh_from_db(self, using=None, fields=None):
"""
Reload field values from the database.
By default, the reloading happens from the database this instance was
loaded from, or by the read router if this instance wasn't loaded from
any database. The using parameter will override the default.
Fields can be used to specify which fields to reload. The fields
should be an iterable of field attnames. If fields is None, then
all non-deferred fields are reloaded.
When accessing deferred fields of an instance, the deferred loading
of the field will call this method.
"""
if fields is None:
self._prefetched_objects_cache = {}
else:
prefetched_objects_cache = getattr(self, '_prefetched_objects_cache', ())
for field in fields:
if field in prefetched_objects_cache:
del prefetched_objects_cache[field]
fields.remove(field)
if not fields:
return
if any(LOOKUP_SEP in f for f in fields):
raise ValueError(
'Found "%s" in fields argument. Relations and transforms '
'are not allowed in fields.' % LOOKUP_SEP)
hints = {'instance': self}
db_instance_qs = self.__class__._base_manager.db_manager(using, hints=hints).filter(pk=self.pk)
# Use provided fields, if not set then reload all non-deferred fields.
deferred_fields = self.get_deferred_fields()
if fields is not None:
fields = list(fields)
db_instance_qs = db_instance_qs.only(*fields)
elif deferred_fields:
fields = [f.attname for f in self._meta.concrete_fields
if f.attname not in deferred_fields]
db_instance_qs = db_instance_qs.only(*fields)
db_instance = db_instance_qs.get()
non_loaded_fields = db_instance.get_deferred_fields()
for field in self._meta.concrete_fields:
if field.attname in non_loaded_fields:
# This field wasn't refreshed - skip ahead.
continue
setattr(self, field.attname, getattr(db_instance, field.attname))
# Clear cached foreign keys.
if field.is_relation and field.is_cached(self):
field.delete_cached_value(self)
# Clear cached relations.
for field in self._meta.related_objects:
if field.is_cached(self):
field.delete_cached_value(self)
self._state.db = db_instance._state.db
def serializable_value(self, field_name):
"""
Return the value of the field name for this instance. If the field is
a foreign key, return the id value instead of the object. If there's
no Field object with this name on the model, return the model
attribute's value.
Used to serialize a field's value (in the serializer, or form output,
for example). Normally, you would just access the attribute directly
and not use this method.
"""
try:
field = self._meta.get_field(field_name)
except FieldDoesNotExist:
return getattr(self, field_name)
return getattr(self, field.attname)
def save(self, force_insert=False, force_update=False, using=None,
update_fields=None):
"""
Save the current instance. Override this in a subclass if you want to
control the saving process.
The 'force_insert' and 'force_update' parameters can be used to insist
that the "save" must be an SQL insert or update (or equivalent for
non-SQL backends), respectively. Normally, they should not be set.
"""
self._prepare_related_fields_for_save(operation_name='save')
using = using or router.db_for_write(self.__class__, instance=self)
if force_insert and (force_update or update_fields):
raise ValueError("Cannot force both insert and updating in model saving.")
deferred_fields = self.get_deferred_fields()
if update_fields is not None:
# If update_fields is empty, skip the save. We do also check for
# no-op saves later on for inheritance cases. This bailout is
# still needed for skipping signal sending.
if not update_fields:
return
update_fields = frozenset(update_fields)
field_names = set()
for field in self._meta.concrete_fields:
if not field.primary_key:
field_names.add(field.name)
if field.name != field.attname:
field_names.add(field.attname)
non_model_fields = update_fields.difference(field_names)
if non_model_fields:
raise ValueError(
'The following fields do not exist in this model, are m2m '
'fields, or are non-concrete fields: %s'
% ', '.join(non_model_fields)
)
# If saving to the same database, and this model is deferred, then
# automatically do an "update_fields" save on the loaded fields.
elif not force_insert and deferred_fields and using == self._state.db:
field_names = set()
for field in self._meta.concrete_fields:
if not field.primary_key and not hasattr(field, 'through'):
field_names.add(field.attname)
loaded_fields = field_names.difference(deferred_fields)
if loaded_fields:
update_fields = frozenset(loaded_fields)
self.save_base(using=using, force_insert=force_insert,
force_update=force_update, update_fields=update_fields)
save.alters_data = True
def save_base(self, raw=False, force_insert=False,
force_update=False, using=None, update_fields=None):
"""
Handle the parts of saving which should be done only once per save,
yet need to be done in raw saves, too. This includes some sanity
checks and signal sending.
The 'raw' argument is telling save_base not to save any parent
models and not to do any changes to the values before save. This
is used by fixture loading.
"""
using = using or router.db_for_write(self.__class__, instance=self)
assert not (force_insert and (force_update or update_fields))
assert update_fields is None or update_fields
cls = origin = self.__class__
# Skip proxies, but keep the origin as the proxy model.
if cls._meta.proxy:
cls = cls._meta.concrete_model
meta = cls._meta
if not meta.auto_created:
pre_save.send(
sender=origin, instance=self, raw=raw, using=using,
update_fields=update_fields,
)
# A transaction isn't needed if one query is issued.
if meta.parents:
context_manager = transaction.atomic(using=using, savepoint=False)
else:
context_manager = transaction.mark_for_rollback_on_error(using=using)
with context_manager:
parent_inserted = False
if not raw:
parent_inserted = self._save_parents(cls, using, update_fields)
updated = self._save_table(
raw, cls, force_insert or parent_inserted,
force_update, using, update_fields,
)
# Store the database on which the object was saved
self._state.db = using
# Once saved, this is no longer a to-be-added instance.
self._state.adding = False
# Signal that the save is complete
if not meta.auto_created:
post_save.send(
sender=origin, instance=self, created=(not updated),
update_fields=update_fields, raw=raw, using=using,
)
save_base.alters_data = True
def _save_parents(self, cls, using, update_fields):
"""Save all the parents of cls using values from self."""
meta = cls._meta
inserted = False
for parent, field in meta.parents.items():
# Make sure the link fields are synced between parent and self.
if (field and getattr(self, parent._meta.pk.attname) is None and
getattr(self, field.attname) is not None):
setattr(self, parent._meta.pk.attname, getattr(self, field.attname))
parent_inserted = self._save_parents(cls=parent, using=using, update_fields=update_fields)
updated = self._save_table(
cls=parent, using=using, update_fields=update_fields,
force_insert=parent_inserted,
)
if not updated:
inserted = True
# Set the parent's PK value to self.
if field:
setattr(self, field.attname, self._get_pk_val(parent._meta))
# Since we didn't have an instance of the parent handy set
# attname directly, bypassing the descriptor. Invalidate
# the related object cache, in case it's been accidentally
# populated. A fresh instance will be re-built from the
# database if necessary.
if field.is_cached(self):
field.delete_cached_value(self)
return inserted
def _save_table(self, raw=False, cls=None, force_insert=False,
force_update=False, using=None, update_fields=None):
"""
Do the heavy-lifting involved in saving. Update or insert the data
for a single table.
"""
meta = cls._meta
non_pks = [f for f in meta.local_concrete_fields if not f.primary_key]
if update_fields:
non_pks = [f for f in non_pks
if f.name in update_fields or f.attname in update_fields]
pk_val = self._get_pk_val(meta)
if pk_val is None:
pk_val = meta.pk.get_pk_value_on_save(self)
setattr(self, meta.pk.attname, pk_val)
pk_set = pk_val is not None
if not pk_set and (force_update or update_fields):
raise ValueError("Cannot force an update in save() with no primary key.")
updated = False
# Skip an UPDATE when adding an instance and primary key has a default.
if (
not raw and
not force_insert and
self._state.adding and
meta.pk.default and
meta.pk.default is not NOT_PROVIDED
):
force_insert = True
# If possible, try an UPDATE. If that doesn't update anything, do an INSERT.
if pk_set and not force_insert:
base_qs = cls._base_manager.using(using)
values = [(f, None, (getattr(self, f.attname) if raw else f.pre_save(self, False)))
for f in non_pks]
forced_update = update_fields or force_update
updated = self._do_update(base_qs, using, pk_val, values, update_fields,
forced_update)
if force_update and not updated:
raise DatabaseError("Forced update did not affect any rows.")
if update_fields and not updated:
raise DatabaseError("Save with update_fields did not affect any rows.")
if not updated:
if meta.order_with_respect_to:
# If this is a model with an order_with_respect_to
# autopopulate the _order field
field = meta.order_with_respect_to
filter_args = field.get_filter_kwargs_for_object(self)
self._order = cls._base_manager.using(using).filter(**filter_args).aggregate(
_order__max=Coalesce(
ExpressionWrapper(Max('_order') + Value(1), output_field=IntegerField()),
Value(0),
),
)['_order__max']
fields = meta.local_concrete_fields
if not pk_set:
fields = [f for f in fields if f is not meta.auto_field]
returning_fields = meta.db_returning_fields
results = self._do_insert(cls._base_manager, using, fields, returning_fields, raw)
if results:
for value, field in zip(results[0], returning_fields):
setattr(self, field.attname, value)
return updated
def _do_update(self, base_qs, using, pk_val, values, update_fields, forced_update):
"""
Try to update the model. Return True if the model was updated (if an
update query was done and a matching row was found in the DB).
"""
filtered = base_qs.filter(pk=pk_val)
if not values:
# We can end up here when saving a model in inheritance chain where
# update_fields doesn't target any field in current model. In that
# case we just say the update succeeded. Another case ending up here
# is a model with just PK - in that case check that the PK still
# exists.
return update_fields is not None or filtered.exists()
if self._meta.select_on_save and not forced_update:
return (
filtered.exists() and
# It may happen that the object is deleted from the DB right after
# this check, causing the subsequent UPDATE to return zero matching
# rows. The same result can occur in some rare cases when the
# database returns zero despite the UPDATE being executed
# successfully (a row is matched and updated). In order to
# distinguish these two cases, the object's existence in the
# database is again checked for if the UPDATE query returns 0.
(filtered._update(values) > 0 or filtered.exists())
)
return filtered._update(values) > 0
def _do_insert(self, manager, using, fields, returning_fields, raw):
"""
Do an INSERT. If returning_fields is defined then this method should
return the newly created data for the model.
"""
return manager._insert(
[self], fields=fields, returning_fields=returning_fields,
using=using, raw=raw,
)
def _prepare_related_fields_for_save(self, operation_name, fields=None):
# Ensure that a model instance without a PK hasn't been assigned to
# a ForeignKey or OneToOneField on this model. If the field is
# nullable, allowing the save would result in silent data loss.
for field in self._meta.concrete_fields:
if fields and field not in fields:
continue
# If the related field isn't cached, then an instance hasn't been
# assigned and there's no need to worry about this check.
if field.is_relation and field.is_cached(self):
obj = getattr(self, field.name, None)
if not obj:
continue
# A pk may have been assigned manually to a model instance not
# saved to the database (or auto-generated in a case like
# UUIDField), but we allow the save to proceed and rely on the
# database to raise an IntegrityError if applicable. If
# constraints aren't supported by the database, there's the
# unavoidable risk of data corruption.
if obj.pk is None:
# Remove the object from a related instance cache.
if not field.remote_field.multiple:
field.remote_field.delete_cached_value(obj)
raise ValueError(
"%s() prohibited to prevent data loss due to unsaved "
"related object '%s'." % (operation_name, field.name)
)
elif getattr(self, field.attname) in field.empty_values:
# Use pk from related object if it has been saved after
# an assignment.
setattr(self, field.attname, obj.pk)
# If the relationship's pk/to_field was changed, clear the
# cached relationship.
if getattr(obj, field.target_field.attname) != getattr(self, field.attname):
field.delete_cached_value(self)
def delete(self, using=None, keep_parents=False):
if self.pk is None:
raise ValueError(
"%s object can't be deleted because its %s attribute is set "
"to None." % (self._meta.object_name, self._meta.pk.attname)
)
using = using or router.db_for_write(self.__class__, instance=self)
collector = Collector(using=using, origin=self)
collector.collect([self], keep_parents=keep_parents)
return collector.delete()
delete.alters_data = True
def _get_FIELD_display(self, field):
value = getattr(self, field.attname)
choices_dict = dict(make_hashable(field.flatchoices))
# force_str() to coerce lazy strings.
return force_str(choices_dict.get(make_hashable(value), value), strings_only=True)
def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):
if not self.pk:
raise ValueError("get_next/get_previous cannot be used on unsaved objects.")
op = 'gt' if is_next else 'lt'
order = '' if is_next else '-'
param = getattr(self, field.attname)
q = Q((field.name, param), (f'pk__{op}', self.pk), _connector=Q.AND)
q = Q(q, (f'{field.name}__{op}', param), _connector=Q.OR)
qs = self.__class__._default_manager.using(self._state.db).filter(**kwargs).filter(q).order_by(
'%s%s' % (order, field.name), '%spk' % order
)
try:
return qs[0]
except IndexError:
raise self.DoesNotExist("%s matching query does not exist." % self.__class__._meta.object_name)
def _get_next_or_previous_in_order(self, is_next):
cachename = "__%s_order_cache" % is_next
if not hasattr(self, cachename):
op = 'gt' if is_next else 'lt'
order = '_order' if is_next else '-_order'
order_field = self._meta.order_with_respect_to
filter_args = order_field.get_filter_kwargs_for_object(self)
obj = self.__class__._default_manager.filter(**filter_args).filter(**{
'_order__%s' % op: self.__class__._default_manager.values('_order').filter(**{
self._meta.pk.name: self.pk
})
}).order_by(order)[:1].get()
setattr(self, cachename, obj)
return getattr(self, cachename)
def prepare_database_save(self, field):
if self.pk is None:
raise ValueError("Unsaved model instance %r cannot be used in an ORM query." % self)
return getattr(self, field.remote_field.get_related_field().attname)
def clean(self):
"""
Hook for doing any extra model-wide validation after clean() has been
called on every field by self.clean_fields. Any ValidationError raised
by this method will not be associated with a particular field; it will
have a special-case association with the field defined by NON_FIELD_ERRORS.
"""
pass
def validate_unique(self, exclude=None):
"""
Check unique constraints on the model and raise ValidationError if any
failed.
"""
unique_checks, date_checks = self._get_unique_checks(exclude=exclude)
errors = self._perform_unique_checks(unique_checks)
date_errors = self._perform_date_checks(date_checks)
for k, v in date_errors.items():
errors.setdefault(k, []).extend(v)
if errors:
raise ValidationError(errors)
def _get_unique_checks(self, exclude=None):
"""
Return a list of checks to perform. Since validate_unique() could be
called from a ModelForm, some fields may have been excluded; we can't
perform a unique check on a model that is missing fields involved
in that check. Fields that did not validate should also be excluded,
but they need to be passed in via the exclude argument.
"""
if exclude is None:
exclude = []
unique_checks = []
unique_togethers = [(self.__class__, self._meta.unique_together)]
constraints = [(self.__class__, self._meta.total_unique_constraints)]
for parent_class in self._meta.get_parent_list():
if parent_class._meta.unique_together:
unique_togethers.append((parent_class, parent_class._meta.unique_together))
if parent_class._meta.total_unique_constraints:
constraints.append(
(parent_class, parent_class._meta.total_unique_constraints)
)
for model_class, unique_together in unique_togethers:
for check in unique_together:
if not any(name in exclude for name in check):
# Add the check if the field isn't excluded.
unique_checks.append((model_class, tuple(check)))
for model_class, model_constraints in constraints:
for constraint in model_constraints:
if not any(name in exclude for name in constraint.fields):
unique_checks.append((model_class, constraint.fields))
# These are checks for the unique_for_<date/year/month>.
date_checks = []
# Gather a list of checks for fields declared as unique and add them to
# the list of checks.
fields_with_class = [(self.__class__, self._meta.local_fields)]
for parent_class in self._meta.get_parent_list():
fields_with_class.append((parent_class, parent_class._meta.local_fields))
for model_class, fields in fields_with_class:
for f in fields:
name = f.name
if name in exclude:
continue
if f.unique:
unique_checks.append((model_class, (name,)))
if f.unique_for_date and f.unique_for_date not in exclude:
date_checks.append((model_class, 'date', name, f.unique_for_date))
if f.unique_for_year and f.unique_for_year not in exclude:
date_checks.append((model_class, 'year', name, f.unique_for_year))
if f.unique_for_month and f.unique_for_month not in exclude:
date_checks.append((model_class, 'month', name, f.unique_for_month))
return unique_checks, date_checks
def _perform_unique_checks(self, unique_checks):
errors = {}
for model_class, unique_check in unique_checks:
# Try to look up an existing object with the same values as this
# object's values for all the unique field.
lookup_kwargs = {}
for field_name in unique_check:
f = self._meta.get_field(field_name)
lookup_value = getattr(self, f.attname)
# TODO: Handle multiple backends with different feature flags.
if (lookup_value is None or
(lookup_value == '' and connection.features.interprets_empty_strings_as_nulls)):
# no value, skip the lookup
continue
if f.primary_key and not self._state.adding:
# no need to check for unique primary key when editing
continue
lookup_kwargs[str(field_name)] = lookup_value
# some fields were skipped, no reason to do the check
if len(unique_check) != len(lookup_kwargs):
continue
qs = model_class._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
# Note that we need to use the pk as defined by model_class, not
# self.pk. These can be different fields because model inheritance
# allows single model to have effectively multiple primary keys.
# Refs #17615.
model_class_pk = self._get_pk_val(model_class._meta)
if not self._state.adding and model_class_pk is not None:
qs = qs.exclude(pk=model_class_pk)
if qs.exists():
if len(unique_check) == 1:
key = unique_check[0]
else:
key = NON_FIELD_ERRORS
errors.setdefault(key, []).append(self.unique_error_message(model_class, unique_check))
return errors
def _perform_date_checks(self, date_checks):
errors = {}
for model_class, lookup_type, field, unique_for in date_checks:
lookup_kwargs = {}
# there's a ticket to add a date lookup, we can remove this special
# case if that makes it's way in
date = getattr(self, unique_for)
if date is None:
continue
if lookup_type == 'date':
lookup_kwargs['%s__day' % unique_for] = date.day
lookup_kwargs['%s__month' % unique_for] = date.month
lookup_kwargs['%s__year' % unique_for] = date.year
else:
lookup_kwargs['%s__%s' % (unique_for, lookup_type)] = getattr(date, lookup_type)
lookup_kwargs[field] = getattr(self, field)
qs = model_class._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
if not self._state.adding and self.pk is not None:
qs = qs.exclude(pk=self.pk)
if qs.exists():
errors.setdefault(field, []).append(
self.date_error_message(lookup_type, field, unique_for)
)
return errors
def date_error_message(self, lookup_type, field_name, unique_for):
opts = self._meta
field = opts.get_field(field_name)
return ValidationError(
message=field.error_messages['unique_for_date'],
code='unique_for_date',
params={
'model': self,
'model_name': capfirst(opts.verbose_name),
'lookup_type': lookup_type,
'field': field_name,
'field_label': capfirst(field.verbose_name),
'date_field': unique_for,
'date_field_label': capfirst(opts.get_field(unique_for).verbose_name),
}
)
def unique_error_message(self, model_class, unique_check):
opts = model_class._meta
params = {
'model': self,
'model_class': model_class,
'model_name': capfirst(opts.verbose_name),
'unique_check': unique_check,
}
# A unique field
if len(unique_check) == 1:
field = opts.get_field(unique_check[0])
params['field_label'] = capfirst(field.verbose_name)
return ValidationError(
message=field.error_messages['unique'],
code='unique',
params=params,
)
# unique_together
else:
field_labels = [capfirst(opts.get_field(f).verbose_name) for f in unique_check]
params['field_labels'] = get_text_list(field_labels, _('and'))
return ValidationError(
message=_("%(model_name)s with this %(field_labels)s already exists."),
code='unique_together',
params=params,
)
def full_clean(self, exclude=None, validate_unique=True):
"""
Call clean_fields(), clean(), and validate_unique() on the model.
Raise a ValidationError for any errors that occur.
"""
errors = {}
if exclude is None:
exclude = []
else:
exclude = list(exclude)
try:
self.clean_fields(exclude=exclude)
except ValidationError as e:
errors = e.update_error_dict(errors)
# Form.clean() is run even if other validation fails, so do the
# same with Model.clean() for consistency.
try:
self.clean()
except ValidationError as e:
errors = e.update_error_dict(errors)
# Run unique checks, but only for fields that passed validation.
if validate_unique:
for name in errors:
if name != NON_FIELD_ERRORS and name not in exclude:
exclude.append(name)
try:
self.validate_unique(exclude=exclude)
except ValidationError as e:
errors = e.update_error_dict(errors)
if errors:
raise ValidationError(errors)
def clean_fields(self, exclude=None):
"""
Clean all fields and raise a ValidationError containing a dict
of all validation errors if any occur.
"""
if exclude is None:
exclude = []
errors = {}
for f in self._meta.fields:
if f.name in exclude:
continue
# Skip validation for empty fields with blank=True. The developer
# is responsible for making sure they have a valid value.
raw_value = getattr(self, f.attname)
if f.blank and raw_value in f.empty_values:
continue
try:
setattr(self, f.attname, f.clean(raw_value, self))
except ValidationError as e:
errors[f.name] = e.error_list
if errors:
raise ValidationError(errors)
@classmethod
def check(cls, **kwargs):
errors = [*cls._check_swappable(), *cls._check_model(), *cls._check_managers(**kwargs)]
if not cls._meta.swapped:
databases = kwargs.get('databases') or []
errors += [
*cls._check_fields(**kwargs),
*cls._check_m2m_through_same_relationship(),
*cls._check_long_column_names(databases),
]
clash_errors = (
*cls._check_id_field(),
*cls._check_field_name_clashes(),
*cls._check_model_name_db_lookup_clashes(),
*cls._check_property_name_related_field_accessor_clashes(),
*cls._check_single_primary_key(),
)
errors.extend(clash_errors)
# If there are field name clashes, hide consequent column name
# clashes.
if not clash_errors:
errors.extend(cls._check_column_name_clashes())
errors += [
*cls._check_index_together(),
*cls._check_unique_together(),
*cls._check_indexes(databases),
*cls._check_ordering(),
*cls._check_constraints(databases),
*cls._check_default_pk(),
]
return errors
@classmethod
def _check_default_pk(cls):
if (
not cls._meta.abstract and
cls._meta.pk.auto_created and
# Inherited PKs are checked in parents models.
not (
isinstance(cls._meta.pk, OneToOneField) and
cls._meta.pk.remote_field.parent_link
) and
not settings.is_overridden('DEFAULT_AUTO_FIELD') and
cls._meta.app_config and
not cls._meta.app_config._is_default_auto_field_overridden
):
return [
checks.Warning(
f"Auto-created primary key used when not defining a "
f"primary key type, by default "
f"'{settings.DEFAULT_AUTO_FIELD}'.",
hint=(
f"Configure the DEFAULT_AUTO_FIELD setting or the "
f"{cls._meta.app_config.__class__.__qualname__}."
f"default_auto_field attribute to point to a subclass "
f"of AutoField, e.g. 'django.db.models.BigAutoField'."
),
obj=cls,
id='models.W042',
),
]
return []
@classmethod
def _check_swappable(cls):
"""Check if the swapped model exists."""
errors = []
if cls._meta.swapped:
try:
apps.get_model(cls._meta.swapped)
except ValueError:
errors.append(
checks.Error(
"'%s' is not of the form 'app_label.app_name'." % cls._meta.swappable,
id='models.E001',
)
)
except LookupError:
app_label, model_name = cls._meta.swapped.split('.')
errors.append(
checks.Error(
"'%s' references '%s.%s', which has not been "
"installed, or is abstract." % (
cls._meta.swappable, app_label, model_name
),
id='models.E002',
)
)
return errors
@classmethod
def _check_model(cls):
errors = []
if cls._meta.proxy:
if cls._meta.local_fields or cls._meta.local_many_to_many:
errors.append(
checks.Error(
"Proxy model '%s' contains model fields." % cls.__name__,
id='models.E017',
)
)
return errors
@classmethod
def _check_managers(cls, **kwargs):
"""Perform all manager checks."""
errors = []
for manager in cls._meta.managers:
errors.extend(manager.check(**kwargs))
return errors
@classmethod
def _check_fields(cls, **kwargs):
"""Perform all field checks."""
errors = []
for field in cls._meta.local_fields:
errors.extend(field.check(**kwargs))
for field in cls._meta.local_many_to_many:
errors.extend(field.check(from_model=cls, **kwargs))
return errors
@classmethod
def _check_m2m_through_same_relationship(cls):
""" Check if no relationship model is used by more than one m2m field.
"""
errors = []
seen_intermediary_signatures = []
fields = cls._meta.local_many_to_many
# Skip when the target model wasn't found.
fields = (f for f in fields if isinstance(f.remote_field.model, ModelBase))
# Skip when the relationship model wasn't found.
fields = (f for f in fields if isinstance(f.remote_field.through, ModelBase))
for f in fields:
signature = (f.remote_field.model, cls, f.remote_field.through, f.remote_field.through_fields)
if signature in seen_intermediary_signatures:
errors.append(
checks.Error(
"The model has two identical many-to-many relations "
"through the intermediate model '%s'." %
f.remote_field.through._meta.label,
obj=cls,
id='models.E003',
)
)
else:
seen_intermediary_signatures.append(signature)
return errors
@classmethod
def _check_id_field(cls):
"""Check if `id` field is a primary key."""
fields = [f for f in cls._meta.local_fields if f.name == 'id' and f != cls._meta.pk]
# fields is empty or consists of the invalid "id" field
if fields and not fields[0].primary_key and cls._meta.pk.name == 'id':
return [
checks.Error(
"'id' can only be used as a field name if the field also "
"sets 'primary_key=True'.",
obj=cls,
id='models.E004',
)
]
else:
return []
@classmethod
def _check_field_name_clashes(cls):
"""Forbid field shadowing in multi-table inheritance."""
errors = []
used_fields = {} # name or attname -> field
# Check that multi-inheritance doesn't cause field name shadowing.
for parent in cls._meta.get_parent_list():
for f in parent._meta.local_fields:
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
if clash:
errors.append(
checks.Error(
"The field '%s' from parent model "
"'%s' clashes with the field '%s' "
"from parent model '%s'." % (
clash.name, clash.model._meta,
f.name, f.model._meta
),
obj=cls,
id='models.E005',
)
)
used_fields[f.name] = f
used_fields[f.attname] = f
# Check that fields defined in the model don't clash with fields from
# parents, including auto-generated fields like multi-table inheritance
# child accessors.
for parent in cls._meta.get_parent_list():
for f in parent._meta.get_fields():
if f not in used_fields:
used_fields[f.name] = f
for f in cls._meta.local_fields:
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
# Note that we may detect clash between user-defined non-unique
# field "id" and automatically added unique field "id", both
# defined at the same model. This special case is considered in
# _check_id_field and here we ignore it.
id_conflict = f.name == "id" and clash and clash.name == "id" and clash.model == cls
if clash and not id_conflict:
errors.append(
checks.Error(
"The field '%s' clashes with the field '%s' "
"from model '%s'." % (
f.name, clash.name, clash.model._meta
),
obj=f,
id='models.E006',
)
)
used_fields[f.name] = f
used_fields[f.attname] = f
return errors
@classmethod
def _check_column_name_clashes(cls):
# Store a list of column names which have already been used by other fields.
used_column_names = []
errors = []
for f in cls._meta.local_fields:
_, column_name = f.get_attname_column()
# Ensure the column name is not already in use.
if column_name and column_name in used_column_names:
errors.append(
checks.Error(
"Field '%s' has column name '%s' that is used by "
"another field." % (f.name, column_name),
hint="Specify a 'db_column' for the field.",
obj=cls,
id='models.E007'
)
)
else:
used_column_names.append(column_name)
return errors
@classmethod
def _check_model_name_db_lookup_clashes(cls):
errors = []
model_name = cls.__name__
if model_name.startswith('_') or model_name.endswith('_'):
errors.append(
checks.Error(
"The model name '%s' cannot start or end with an underscore "
"as it collides with the query lookup syntax." % model_name,
obj=cls,
id='models.E023'
)
)
elif LOOKUP_SEP in model_name:
errors.append(
checks.Error(
"The model name '%s' cannot contain double underscores as "
"it collides with the query lookup syntax." % model_name,
obj=cls,
id='models.E024'
)
)
return errors
@classmethod
def _check_property_name_related_field_accessor_clashes(cls):
errors = []
property_names = cls._meta._property_names
related_field_accessors = (
f.get_attname() for f in cls._meta._get_fields(reverse=False)
if f.is_relation and f.related_model is not None
)
for accessor in related_field_accessors:
if accessor in property_names:
errors.append(
checks.Error(
"The property '%s' clashes with a related field "
"accessor." % accessor,
obj=cls,
id='models.E025',
)
)
return errors
@classmethod
def _check_single_primary_key(cls):
errors = []
if sum(1 for f in cls._meta.local_fields if f.primary_key) > 1:
errors.append(
checks.Error(
"The model cannot have more than one field with "
"'primary_key=True'.",
obj=cls,
id='models.E026',
)
)
return errors
@classmethod
def _check_index_together(cls):
"""Check the value of "index_together" option."""
if not isinstance(cls._meta.index_together, (tuple, list)):
return [
checks.Error(
"'index_together' must be a list or tuple.",
obj=cls,
id='models.E008',
)
]
elif any(not isinstance(fields, (tuple, list)) for fields in cls._meta.index_together):
return [
checks.Error(
"All 'index_together' elements must be lists or tuples.",
obj=cls,
id='models.E009',
)
]
else:
errors = []
for fields in cls._meta.index_together:
errors.extend(cls._check_local_fields(fields, "index_together"))
return errors
@classmethod
def _check_unique_together(cls):
"""Check the value of "unique_together" option."""
if not isinstance(cls._meta.unique_together, (tuple, list)):
return [
checks.Error(
"'unique_together' must be a list or tuple.",
obj=cls,
id='models.E010',
)
]
elif any(not isinstance(fields, (tuple, list)) for fields in cls._meta.unique_together):
return [
checks.Error(
"All 'unique_together' elements must be lists or tuples.",
obj=cls,
id='models.E011',
)
]
else:
errors = []
for fields in cls._meta.unique_together:
errors.extend(cls._check_local_fields(fields, "unique_together"))
return errors
@classmethod
def _check_indexes(cls, databases):
"""Check fields, names, and conditions of indexes."""
errors = []
references = set()
for index in cls._meta.indexes:
# Index name can't start with an underscore or a number, restricted
# for cross-database compatibility with Oracle.
if index.name[0] == '_' or index.name[0].isdigit():
errors.append(
checks.Error(
"The index name '%s' cannot start with an underscore "
"or a number." % index.name,
obj=cls,
id='models.E033',
),
)
if len(index.name) > index.max_name_length:
errors.append(
checks.Error(
"The index name '%s' cannot be longer than %d "
"characters." % (index.name, index.max_name_length),
obj=cls,
id='models.E034',
),
)
if index.contains_expressions:
for expression in index.expressions:
references.update(
ref[0] for ref in cls._get_expr_references(expression)
)
for db in databases:
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
if not (
connection.features.supports_partial_indexes or
'supports_partial_indexes' in cls._meta.required_db_features
) and any(index.condition is not None for index in cls._meta.indexes):
errors.append(
checks.Warning(
'%s does not support indexes with conditions.'
% connection.display_name,
hint=(
"Conditions will be ignored. Silence this warning "
"if you don't care about it."
),
obj=cls,
id='models.W037',
)
)
if not (
connection.features.supports_covering_indexes or
'supports_covering_indexes' in cls._meta.required_db_features
) and any(index.include for index in cls._meta.indexes):
errors.append(
checks.Warning(
'%s does not support indexes with non-key columns.'
% connection.display_name,
hint=(
"Non-key columns will be ignored. Silence this "
"warning if you don't care about it."
),
obj=cls,
id='models.W040',
)
)
if not (
connection.features.supports_expression_indexes or
'supports_expression_indexes' in cls._meta.required_db_features
) and any(index.contains_expressions for index in cls._meta.indexes):
errors.append(
checks.Warning(
'%s does not support indexes on expressions.'
% connection.display_name,
hint=(
"An index won't be created. Silence this warning "
"if you don't care about it."
),
obj=cls,
id='models.W043',
)
)
fields = [field for index in cls._meta.indexes for field, _ in index.fields_orders]
fields += [include for index in cls._meta.indexes for include in index.include]
fields += references
errors.extend(cls._check_local_fields(fields, 'indexes'))
return errors
@classmethod
def _check_local_fields(cls, fields, option):
from django.db import models
# In order to avoid hitting the relation tree prematurely, we use our
# own fields_map instead of using get_field()
forward_fields_map = {}
for field in cls._meta._get_fields(reverse=False):
forward_fields_map[field.name] = field
if hasattr(field, 'attname'):
forward_fields_map[field.attname] = field
errors = []
for field_name in fields:
try:
field = forward_fields_map[field_name]
except KeyError:
errors.append(
checks.Error(
"'%s' refers to the nonexistent field '%s'." % (
option, field_name,
),
obj=cls,
id='models.E012',
)
)
else:
if isinstance(field.remote_field, models.ManyToManyRel):
errors.append(
checks.Error(
"'%s' refers to a ManyToManyField '%s', but "
"ManyToManyFields are not permitted in '%s'." % (
option, field_name, option,
),
obj=cls,
id='models.E013',
)
)
elif field not in cls._meta.local_fields:
errors.append(
checks.Error(
"'%s' refers to field '%s' which is not local to model '%s'."
% (option, field_name, cls._meta.object_name),
hint="This issue may be caused by multi-table inheritance.",
obj=cls,
id='models.E016',
)
)
return errors
@classmethod
def _check_ordering(cls):
"""
Check "ordering" option -- is it a list of strings and do all fields
exist?
"""
if cls._meta._ordering_clash:
return [
checks.Error(
"'ordering' and 'order_with_respect_to' cannot be used together.",
obj=cls,
id='models.E021',
),
]
if cls._meta.order_with_respect_to or not cls._meta.ordering:
return []
if not isinstance(cls._meta.ordering, (list, tuple)):
return [
checks.Error(
"'ordering' must be a tuple or list (even if you want to order by only one field).",
obj=cls,
id='models.E014',
)
]
errors = []
fields = cls._meta.ordering
# Skip expressions and '?' fields.
fields = (f for f in fields if isinstance(f, str) and f != '?')
# Convert "-field" to "field".
fields = ((f[1:] if f.startswith('-') else f) for f in fields)
# Separate related fields and non-related fields.
_fields = []
related_fields = []
for f in fields:
if LOOKUP_SEP in f:
related_fields.append(f)
else:
_fields.append(f)
fields = _fields
# Check related fields.
for field in related_fields:
_cls = cls
fld = None
for part in field.split(LOOKUP_SEP):
try:
# pk is an alias that won't be found by opts.get_field.
if part == 'pk':
fld = _cls._meta.pk
else:
fld = _cls._meta.get_field(part)
if fld.is_relation:
_cls = fld.path_infos[-1].to_opts.model
else:
_cls = None
except (FieldDoesNotExist, AttributeError):
if fld is None or (
fld.get_transform(part) is None and fld.get_lookup(part) is None
):
errors.append(
checks.Error(
"'ordering' refers to the nonexistent field, "
"related field, or lookup '%s'." % field,
obj=cls,
id='models.E015',
)
)
# Skip ordering on pk. This is always a valid order_by field
# but is an alias and therefore won't be found by opts.get_field.
fields = {f for f in fields if f != 'pk'}
# Check for invalid or nonexistent fields in ordering.
invalid_fields = []
# Any field name that is not present in field_names does not exist.
# Also, ordering by m2m fields is not allowed.
opts = cls._meta
valid_fields = set(chain.from_iterable(
(f.name, f.attname) if not (f.auto_created and not f.concrete) else (f.field.related_query_name(),)
for f in chain(opts.fields, opts.related_objects)
))
invalid_fields.extend(fields - valid_fields)
for invalid_field in invalid_fields:
errors.append(
checks.Error(
"'ordering' refers to the nonexistent field, related "
"field, or lookup '%s'." % invalid_field,
obj=cls,
id='models.E015',
)
)
return errors
@classmethod
def _check_long_column_names(cls, databases):
"""
Check that any auto-generated column names are shorter than the limits
for each database in which the model will be created.
"""
if not databases:
return []
errors = []
allowed_len = None
db_alias = None
# Find the minimum max allowed length among all specified db_aliases.
for db in databases:
# skip databases where the model won't be created
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
max_name_length = connection.ops.max_name_length()
if max_name_length is None or connection.features.truncates_names:
continue
else:
if allowed_len is None:
allowed_len = max_name_length
db_alias = db
elif max_name_length < allowed_len:
allowed_len = max_name_length
db_alias = db
if allowed_len is None:
return errors
for f in cls._meta.local_fields:
_, column_name = f.get_attname_column()
# Check if auto-generated name for the field is too long
# for the database.
if f.db_column is None and column_name is not None and len(column_name) > allowed_len:
errors.append(
checks.Error(
'Autogenerated column name too long for field "%s". '
'Maximum length is "%s" for database "%s".'
% (column_name, allowed_len, db_alias),
hint="Set the column name manually using 'db_column'.",
obj=cls,
id='models.E018',
)
)
for f in cls._meta.local_many_to_many:
# Skip nonexistent models.
if isinstance(f.remote_field.through, str):
continue
# Check if auto-generated name for the M2M field is too long
# for the database.
for m2m in f.remote_field.through._meta.local_fields:
_, rel_name = m2m.get_attname_column()
if m2m.db_column is None and rel_name is not None and len(rel_name) > allowed_len:
errors.append(
checks.Error(
'Autogenerated column name too long for M2M field '
'"%s". Maximum length is "%s" for database "%s".'
% (rel_name, allowed_len, db_alias),
hint=(
"Use 'through' to create a separate model for "
"M2M and then set column_name using 'db_column'."
),
obj=cls,
id='models.E019',
)
)
return errors
@classmethod
def _get_expr_references(cls, expr):
if isinstance(expr, Q):
for child in expr.children:
if isinstance(child, tuple):
lookup, value = child
yield tuple(lookup.split(LOOKUP_SEP))
yield from cls._get_expr_references(value)
else:
yield from cls._get_expr_references(child)
elif isinstance(expr, F):
yield tuple(expr.name.split(LOOKUP_SEP))
elif hasattr(expr, 'get_source_expressions'):
for src_expr in expr.get_source_expressions():
yield from cls._get_expr_references(src_expr)
@classmethod
def _check_constraints(cls, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
if not (
connection.features.supports_table_check_constraints or
'supports_table_check_constraints' in cls._meta.required_db_features
) and any(
isinstance(constraint, CheckConstraint)
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
'%s does not support check constraints.' % connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id='models.W027',
)
)
if not (
connection.features.supports_partial_indexes or
'supports_partial_indexes' in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint) and constraint.condition is not None
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
'%s does not support unique constraints with '
'conditions.' % connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id='models.W036',
)
)
if not (
connection.features.supports_deferrable_unique_constraints or
'supports_deferrable_unique_constraints' in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint) and constraint.deferrable is not None
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
'%s does not support deferrable unique constraints.'
% connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id='models.W038',
)
)
if not (
connection.features.supports_covering_indexes or
'supports_covering_indexes' in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint) and constraint.include
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
'%s does not support unique constraints with non-key '
'columns.' % connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id='models.W039',
)
)
if not (
connection.features.supports_expression_indexes or
'supports_expression_indexes' in cls._meta.required_db_features
) and any(
isinstance(constraint, UniqueConstraint) and constraint.contains_expressions
for constraint in cls._meta.constraints
):
errors.append(
checks.Warning(
'%s does not support unique constraints on '
'expressions.' % connection.display_name,
hint=(
"A constraint won't be created. Silence this "
"warning if you don't care about it."
),
obj=cls,
id='models.W044',
)
)
fields = set(chain.from_iterable(
(*constraint.fields, *constraint.include)
for constraint in cls._meta.constraints if isinstance(constraint, UniqueConstraint)
))
references = set()
for constraint in cls._meta.constraints:
if isinstance(constraint, UniqueConstraint):
if (
connection.features.supports_partial_indexes or
'supports_partial_indexes' not in cls._meta.required_db_features
) and isinstance(constraint.condition, Q):
references.update(cls._get_expr_references(constraint.condition))
if (
connection.features.supports_expression_indexes or
'supports_expression_indexes' not in cls._meta.required_db_features
) and constraint.contains_expressions:
for expression in constraint.expressions:
references.update(cls._get_expr_references(expression))
elif isinstance(constraint, CheckConstraint):
if (
connection.features.supports_table_check_constraints or
'supports_table_check_constraints' not in cls._meta.required_db_features
) and isinstance(constraint.check, Q):
references.update(cls._get_expr_references(constraint.check))
for field_name, *lookups in references:
# pk is an alias that won't be found by opts.get_field.
if field_name != 'pk':
fields.add(field_name)
if not lookups:
# If it has no lookups it cannot result in a JOIN.
continue
try:
if field_name == 'pk':
field = cls._meta.pk
else:
field = cls._meta.get_field(field_name)
if not field.is_relation or field.many_to_many or field.one_to_many:
continue
except FieldDoesNotExist:
continue
# JOIN must happen at the first lookup.
first_lookup = lookups[0]
if (
hasattr(field, 'get_transform') and
hasattr(field, 'get_lookup') and
field.get_transform(first_lookup) is None and
field.get_lookup(first_lookup) is None
):
errors.append(
checks.Error(
"'constraints' refers to the joined field '%s'."
% LOOKUP_SEP.join([field_name] + lookups),
obj=cls,
id='models.E041',
)
)
errors.extend(cls._check_local_fields(fields, 'constraints'))
return errors
############################################
# HELPER FUNCTIONS (CURRIED MODEL METHODS) #
############################################
# ORDERING METHODS #########################
def method_set_order(self, ordered_obj, id_list, using=None):
if using is None:
using = DEFAULT_DB_ALIAS
order_wrt = ordered_obj._meta.order_with_respect_to
filter_args = order_wrt.get_forward_related_filter(self)
ordered_obj.objects.db_manager(using).filter(**filter_args).bulk_update([
ordered_obj(pk=pk, _order=order) for order, pk in enumerate(id_list)
], ['_order'])
def method_get_order(self, ordered_obj):
order_wrt = ordered_obj._meta.order_with_respect_to
filter_args = order_wrt.get_forward_related_filter(self)
pk_name = ordered_obj._meta.pk.name
return ordered_obj.objects.filter(**filter_args).values_list(pk_name, flat=True)
def make_foreign_order_accessors(model, related_model):
setattr(
related_model,
'get_%s_order' % model.__name__.lower(),
partialmethod(method_get_order, model)
)
setattr(
related_model,
'set_%s_order' % model.__name__.lower(),
partialmethod(method_set_order, model)
)
########
# MISC #
########
def model_unpickle(model_id):
"""Used to unpickle Model subclasses with deferred fields."""
if isinstance(model_id, tuple):
model = apps.get_model(*model_id)
else:
# Backwards compat - the model was cached directly in earlier versions.
model = model_id
return model.__new__(model)
model_unpickle.__safe_for_unpickle__ = True
|
55597b919c7af3c7a3e9269ed25902f5e8bcaffe0b48c922121658462a120ad8 | import functools
from collections import namedtuple
def make_model_tuple(model):
"""
Take a model or a string of the form "app_label.ModelName" and return a
corresponding ("app_label", "modelname") tuple. If a tuple is passed in,
assume it's a valid model tuple already and return it unchanged.
"""
try:
if isinstance(model, tuple):
model_tuple = model
elif isinstance(model, str):
app_label, model_name = model.split(".")
model_tuple = app_label, model_name.lower()
else:
model_tuple = model._meta.app_label, model._meta.model_name
assert len(model_tuple) == 2
return model_tuple
except (ValueError, AssertionError):
raise ValueError(
"Invalid model reference '%s'. String model references "
"must be of the form 'app_label.ModelName'." % model
)
def resolve_callables(mapping):
"""
Generate key/value pairs for the given mapping where the values are
evaluated if they're callable.
"""
for k, v in mapping.items():
yield k, v() if callable(v) else v
def unpickle_named_row(names, values):
return create_namedtuple_class(*names)(*values)
@functools.lru_cache
def create_namedtuple_class(*names):
# Cache type() with @lru_cache since it's too slow to be called for every
# QuerySet evaluation.
def __reduce__(self):
return unpickle_named_row, (names, tuple(self))
return type(
'Row',
(namedtuple('Row', names),),
{'__reduce__': __reduce__, '__slots__': ()},
)
|
f97c6ed500f25b12c6f14146892db7b8953fbddce20402046b3e6e440c9e48c1 | """
Constants used across the ORM in general.
"""
from enum import Enum
# Separator used to split filter strings apart.
LOOKUP_SEP = '__'
class OnConflict(Enum):
IGNORE = 'ignore'
UPDATE = 'update'
|
035429fae18709c2a841cf060ed4fa4bd28a3bc26c5a40929ccca6b63c905024 | import copy
import datetime
import functools
import inspect
from decimal import Decimal
from uuid import UUID
from django.core.exceptions import EmptyResultSet, FieldError
from django.db import DatabaseError, NotSupportedError, connection
from django.db.models import fields
from django.db.models.constants import LOOKUP_SEP
from django.db.models.query_utils import Q
from django.utils.deconstruct import deconstructible
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
class SQLiteNumericMixin:
"""
Some expressions with output_field=DecimalField() must be cast to
numeric to be properly filtered.
"""
def as_sqlite(self, compiler, connection, **extra_context):
sql, params = self.as_sql(compiler, connection, **extra_context)
try:
if self.output_field.get_internal_type() == 'DecimalField':
sql = 'CAST(%s AS NUMERIC)' % sql
except FieldError:
pass
return sql, params
class Combinable:
"""
Provide the ability to combine one or two objects with
some connector. For example F('foo') + F('bar').
"""
# Arithmetic connectors
ADD = '+'
SUB = '-'
MUL = '*'
DIV = '/'
POW = '^'
# The following is a quoted % operator - it is quoted because it can be
# used in strings that also have parameter substitution.
MOD = '%%'
# Bitwise operators - note that these are generated by .bitand()
# and .bitor(), the '&' and '|' are reserved for boolean operator
# usage.
BITAND = '&'
BITOR = '|'
BITLEFTSHIFT = '<<'
BITRIGHTSHIFT = '>>'
BITXOR = '#'
def _combine(self, other, connector, reversed):
if not hasattr(other, 'resolve_expression'):
# everything must be resolvable to an expression
other = Value(other)
if reversed:
return CombinedExpression(other, connector, self)
return CombinedExpression(self, connector, other)
#############
# OPERATORS #
#############
def __neg__(self):
return self._combine(-1, self.MUL, False)
def __add__(self, other):
return self._combine(other, self.ADD, False)
def __sub__(self, other):
return self._combine(other, self.SUB, False)
def __mul__(self, other):
return self._combine(other, self.MUL, False)
def __truediv__(self, other):
return self._combine(other, self.DIV, False)
def __mod__(self, other):
return self._combine(other, self.MOD, False)
def __pow__(self, other):
return self._combine(other, self.POW, False)
def __and__(self, other):
if getattr(self, 'conditional', False) and getattr(other, 'conditional', False):
return Q(self) & Q(other)
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
def bitand(self, other):
return self._combine(other, self.BITAND, False)
def bitleftshift(self, other):
return self._combine(other, self.BITLEFTSHIFT, False)
def bitrightshift(self, other):
return self._combine(other, self.BITRIGHTSHIFT, False)
def bitxor(self, other):
return self._combine(other, self.BITXOR, False)
def __or__(self, other):
if getattr(self, 'conditional', False) and getattr(other, 'conditional', False):
return Q(self) | Q(other)
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
def bitor(self, other):
return self._combine(other, self.BITOR, False)
def __radd__(self, other):
return self._combine(other, self.ADD, True)
def __rsub__(self, other):
return self._combine(other, self.SUB, True)
def __rmul__(self, other):
return self._combine(other, self.MUL, True)
def __rtruediv__(self, other):
return self._combine(other, self.DIV, True)
def __rmod__(self, other):
return self._combine(other, self.MOD, True)
def __rpow__(self, other):
return self._combine(other, self.POW, True)
def __rand__(self, other):
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
def __ror__(self, other):
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
class BaseExpression:
"""Base class for all query expressions."""
empty_result_set_value = NotImplemented
# aggregate specific fields
is_summary = False
_output_field_resolved_to_none = False
# Can the expression be used in a WHERE clause?
filterable = True
# Can the expression can be used as a source expression in Window?
window_compatible = False
def __init__(self, output_field=None):
if output_field is not None:
self.output_field = output_field
def __getstate__(self):
state = self.__dict__.copy()
state.pop('convert_value', None)
return state
def get_db_converters(self, connection):
return (
[]
if self.convert_value is self._convert_value_noop else
[self.convert_value]
) + self.output_field.get_db_converters(connection)
def get_source_expressions(self):
return []
def set_source_expressions(self, exprs):
assert not exprs
def _parse_expressions(self, *expressions):
return [
arg if hasattr(arg, 'resolve_expression') else (
F(arg) if isinstance(arg, str) else Value(arg)
) for arg in expressions
]
def as_sql(self, compiler, connection):
"""
Responsible for returning a (sql, [params]) tuple to be included
in the current query.
Different backends can provide their own implementation, by
providing an `as_{vendor}` method and patching the Expression:
```
def override_as_sql(self, compiler, connection):
# custom logic
return super().as_sql(compiler, connection)
setattr(Expression, 'as_' + connection.vendor, override_as_sql)
```
Arguments:
* compiler: the query compiler responsible for generating the query.
Must have a compile method, returning a (sql, [params]) tuple.
Calling compiler(value) will return a quoted `value`.
* connection: the database connection used for the current query.
Return: (sql, params)
Where `sql` is a string containing ordered sql parameters to be
replaced with the elements of the list `params`.
"""
raise NotImplementedError("Subclasses must implement as_sql()")
@cached_property
def contains_aggregate(self):
return any(expr and expr.contains_aggregate for expr in self.get_source_expressions())
@cached_property
def contains_over_clause(self):
return any(expr and expr.contains_over_clause for expr in self.get_source_expressions())
@cached_property
def contains_column_references(self):
return any(expr and expr.contains_column_references for expr in self.get_source_expressions())
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
"""
Provide the chance to do any preprocessing or validation before being
added to the query.
Arguments:
* query: the backend query implementation
* allow_joins: boolean allowing or denying use of joins
in this query
* reuse: a set of reusable joins for multijoins
* summarize: a terminal aggregate clause
* for_save: whether this expression about to be used in a save or update
Return: an Expression to be added to the query.
"""
c = self.copy()
c.is_summary = summarize
c.set_source_expressions([
expr.resolve_expression(query, allow_joins, reuse, summarize)
if expr else None
for expr in c.get_source_expressions()
])
return c
@property
def conditional(self):
return isinstance(self.output_field, fields.BooleanField)
@property
def field(self):
return self.output_field
@cached_property
def output_field(self):
"""Return the output type of this expressions."""
output_field = self._resolve_output_field()
if output_field is None:
self._output_field_resolved_to_none = True
raise FieldError('Cannot resolve expression type, unknown output_field')
return output_field
@cached_property
def _output_field_or_none(self):
"""
Return the output field of this expression, or None if
_resolve_output_field() didn't return an output type.
"""
try:
return self.output_field
except FieldError:
if not self._output_field_resolved_to_none:
raise
def _resolve_output_field(self):
"""
Attempt to infer the output type of the expression. If the output
fields of all source fields match then, simply infer the same type
here. This isn't always correct, but it makes sense most of the time.
Consider the difference between `2 + 2` and `2 / 3`. Inferring
the type here is a convenience for the common case. The user should
supply their own output_field with more complex computations.
If a source's output field resolves to None, exclude it from this check.
If all sources are None, then an error is raised higher up the stack in
the output_field property.
"""
sources_iter = (source for source in self.get_source_fields() if source is not None)
for output_field in sources_iter:
for source in sources_iter:
if not isinstance(output_field, source.__class__):
raise FieldError(
'Expression contains mixed types: %s, %s. You must '
'set output_field.' % (
output_field.__class__.__name__,
source.__class__.__name__,
)
)
return output_field
@staticmethod
def _convert_value_noop(value, expression, connection):
return value
@cached_property
def convert_value(self):
"""
Expressions provide their own converters because users have the option
of manually specifying the output_field which may be a different type
from the one the database returns.
"""
field = self.output_field
internal_type = field.get_internal_type()
if internal_type == 'FloatField':
return lambda value, expression, connection: None if value is None else float(value)
elif internal_type.endswith('IntegerField'):
return lambda value, expression, connection: None if value is None else int(value)
elif internal_type == 'DecimalField':
return lambda value, expression, connection: None if value is None else Decimal(value)
return self._convert_value_noop
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
def get_transform(self, name):
return self.output_field.get_transform(name)
def relabeled_clone(self, change_map):
clone = self.copy()
clone.set_source_expressions([
e.relabeled_clone(change_map) if e is not None else None
for e in self.get_source_expressions()
])
return clone
def copy(self):
return copy.copy(self)
def get_group_by_cols(self, alias=None):
if not self.contains_aggregate:
return [self]
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def get_source_fields(self):
"""Return the underlying field types used by this aggregate."""
return [e._output_field_or_none for e in self.get_source_expressions()]
def asc(self, **kwargs):
return OrderBy(self, **kwargs)
def desc(self, **kwargs):
return OrderBy(self, descending=True, **kwargs)
def reverse_ordering(self):
return self
def flatten(self):
"""
Recursively yield this expression and all subexpressions, in
depth-first order.
"""
yield self
for expr in self.get_source_expressions():
if expr:
if hasattr(expr, 'flatten'):
yield from expr.flatten()
else:
yield expr
def select_format(self, compiler, sql, params):
"""
Custom format for select clauses. For example, EXISTS expressions need
to be wrapped in CASE WHEN on Oracle.
"""
if hasattr(self.output_field, 'select_format'):
return self.output_field.select_format(compiler, sql, params)
return sql, params
@deconstructible
class Expression(BaseExpression, Combinable):
"""An expression that can be combined with other expressions."""
@cached_property
def identity(self):
constructor_signature = inspect.signature(self.__init__)
args, kwargs = self._constructor_args
signature = constructor_signature.bind_partial(*args, **kwargs)
signature.apply_defaults()
arguments = signature.arguments.items()
identity = [self.__class__]
for arg, value in arguments:
if isinstance(value, fields.Field):
if value.name and value.model:
value = (value.model._meta.label, value.name)
else:
value = type(value)
else:
value = make_hashable(value)
identity.append((arg, value))
return tuple(identity)
def __eq__(self, other):
if not isinstance(other, Expression):
return NotImplemented
return other.identity == self.identity
def __hash__(self):
return hash(self.identity)
_connector_combinators = {
connector: [
(fields.IntegerField, fields.IntegerField, fields.IntegerField),
(fields.IntegerField, fields.DecimalField, fields.DecimalField),
(fields.DecimalField, fields.IntegerField, fields.DecimalField),
(fields.IntegerField, fields.FloatField, fields.FloatField),
(fields.FloatField, fields.IntegerField, fields.FloatField),
]
for connector in (Combinable.ADD, Combinable.SUB, Combinable.MUL, Combinable.DIV)
}
@functools.lru_cache(maxsize=128)
def _resolve_combined_type(connector, lhs_type, rhs_type):
combinators = _connector_combinators.get(connector, ())
for combinator_lhs_type, combinator_rhs_type, combined_type in combinators:
if issubclass(lhs_type, combinator_lhs_type) and issubclass(rhs_type, combinator_rhs_type):
return combined_type
class CombinedExpression(SQLiteNumericMixin, Expression):
def __init__(self, lhs, connector, rhs, output_field=None):
super().__init__(output_field=output_field)
self.connector = connector
self.lhs = lhs
self.rhs = rhs
def __repr__(self):
return "<{}: {}>".format(self.__class__.__name__, self)
def __str__(self):
return "{} {} {}".format(self.lhs, self.connector, self.rhs)
def get_source_expressions(self):
return [self.lhs, self.rhs]
def set_source_expressions(self, exprs):
self.lhs, self.rhs = exprs
def _resolve_output_field(self):
try:
return super()._resolve_output_field()
except FieldError:
combined_type = _resolve_combined_type(
self.connector,
type(self.lhs.output_field),
type(self.rhs.output_field),
)
if combined_type is None:
raise
return combined_type()
def as_sql(self, compiler, connection):
expressions = []
expression_params = []
sql, params = compiler.compile(self.lhs)
expressions.append(sql)
expression_params.extend(params)
sql, params = compiler.compile(self.rhs)
expressions.append(sql)
expression_params.extend(params)
# order of precedence
expression_wrapper = '(%s)'
sql = connection.ops.combine_expression(self.connector, expressions)
return expression_wrapper % sql, expression_params
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
lhs = self.lhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
rhs = self.rhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
if not isinstance(self, (DurationExpression, TemporalSubtraction)):
try:
lhs_type = lhs.output_field.get_internal_type()
except (AttributeError, FieldError):
lhs_type = None
try:
rhs_type = rhs.output_field.get_internal_type()
except (AttributeError, FieldError):
rhs_type = None
if 'DurationField' in {lhs_type, rhs_type} and lhs_type != rhs_type:
return DurationExpression(self.lhs, self.connector, self.rhs).resolve_expression(
query, allow_joins, reuse, summarize, for_save,
)
datetime_fields = {'DateField', 'DateTimeField', 'TimeField'}
if self.connector == self.SUB and lhs_type in datetime_fields and lhs_type == rhs_type:
return TemporalSubtraction(self.lhs, self.rhs).resolve_expression(
query, allow_joins, reuse, summarize, for_save,
)
c = self.copy()
c.is_summary = summarize
c.lhs = lhs
c.rhs = rhs
return c
class DurationExpression(CombinedExpression):
def compile(self, side, compiler, connection):
try:
output = side.output_field
except FieldError:
pass
else:
if output.get_internal_type() == 'DurationField':
sql, params = compiler.compile(side)
return connection.ops.format_for_duration_arithmetic(sql), params
return compiler.compile(side)
def as_sql(self, compiler, connection):
if connection.features.has_native_duration_field:
return super().as_sql(compiler, connection)
connection.ops.check_expression_support(self)
expressions = []
expression_params = []
sql, params = self.compile(self.lhs, compiler, connection)
expressions.append(sql)
expression_params.extend(params)
sql, params = self.compile(self.rhs, compiler, connection)
expressions.append(sql)
expression_params.extend(params)
# order of precedence
expression_wrapper = '(%s)'
sql = connection.ops.combine_duration_expression(self.connector, expressions)
return expression_wrapper % sql, expression_params
def as_sqlite(self, compiler, connection, **extra_context):
sql, params = self.as_sql(compiler, connection, **extra_context)
if self.connector in {Combinable.MUL, Combinable.DIV}:
try:
lhs_type = self.lhs.output_field.get_internal_type()
rhs_type = self.rhs.output_field.get_internal_type()
except (AttributeError, FieldError):
pass
else:
allowed_fields = {
'DecimalField', 'DurationField', 'FloatField', 'IntegerField',
}
if lhs_type not in allowed_fields or rhs_type not in allowed_fields:
raise DatabaseError(
f'Invalid arguments for operator {self.connector}.'
)
return sql, params
class TemporalSubtraction(CombinedExpression):
output_field = fields.DurationField()
def __init__(self, lhs, rhs):
super().__init__(lhs, self.SUB, rhs)
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
lhs = compiler.compile(self.lhs)
rhs = compiler.compile(self.rhs)
return connection.ops.subtract_temporals(self.lhs.output_field.get_internal_type(), lhs, rhs)
@deconstructible(path='django.db.models.F')
class F(Combinable):
"""An object capable of resolving references to existing query objects."""
def __init__(self, name):
"""
Arguments:
* name: the name of the field this expression references
"""
self.name = name
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.name)
def resolve_expression(self, query=None, allow_joins=True, reuse=None,
summarize=False, for_save=False):
return query.resolve_ref(self.name, allow_joins, reuse, summarize)
def asc(self, **kwargs):
return OrderBy(self, **kwargs)
def desc(self, **kwargs):
return OrderBy(self, descending=True, **kwargs)
def __eq__(self, other):
return self.__class__ == other.__class__ and self.name == other.name
def __hash__(self):
return hash(self.name)
class ResolvedOuterRef(F):
"""
An object that contains a reference to an outer query.
In this case, the reference to the outer query has been resolved because
the inner query has been used as a subquery.
"""
contains_aggregate = False
def as_sql(self, *args, **kwargs):
raise ValueError(
'This queryset contains a reference to an outer query and may '
'only be used in a subquery.'
)
def resolve_expression(self, *args, **kwargs):
col = super().resolve_expression(*args, **kwargs)
# FIXME: Rename possibly_multivalued to multivalued and fix detection
# for non-multivalued JOINs (e.g. foreign key fields). This should take
# into account only many-to-many and one-to-many relationships.
col.possibly_multivalued = LOOKUP_SEP in self.name
return col
def relabeled_clone(self, relabels):
return self
def get_group_by_cols(self, alias=None):
return []
class OuterRef(F):
contains_aggregate = False
def resolve_expression(self, *args, **kwargs):
if isinstance(self.name, self.__class__):
return self.name
return ResolvedOuterRef(self.name)
def relabeled_clone(self, relabels):
return self
@deconstructible(path='django.db.models.Func')
class Func(SQLiteNumericMixin, Expression):
"""An SQL function call."""
function = None
template = '%(function)s(%(expressions)s)'
arg_joiner = ', '
arity = None # The number of arguments the function accepts.
def __init__(self, *expressions, output_field=None, **extra):
if self.arity is not None and len(expressions) != self.arity:
raise TypeError(
"'%s' takes exactly %s %s (%s given)" % (
self.__class__.__name__,
self.arity,
"argument" if self.arity == 1 else "arguments",
len(expressions),
)
)
super().__init__(output_field=output_field)
self.source_expressions = self._parse_expressions(*expressions)
self.extra = extra
def __repr__(self):
args = self.arg_joiner.join(str(arg) for arg in self.source_expressions)
extra = {**self.extra, **self._get_repr_options()}
if extra:
extra = ', '.join(str(key) + '=' + str(val) for key, val in sorted(extra.items()))
return "{}({}, {})".format(self.__class__.__name__, args, extra)
return "{}({})".format(self.__class__.__name__, args)
def _get_repr_options(self):
"""Return a dict of extra __init__() options to include in the repr."""
return {}
def get_source_expressions(self):
return self.source_expressions
def set_source_expressions(self, exprs):
self.source_expressions = exprs
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
for pos, arg in enumerate(c.source_expressions):
c.source_expressions[pos] = arg.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
def as_sql(self, compiler, connection, function=None, template=None, arg_joiner=None, **extra_context):
connection.ops.check_expression_support(self)
sql_parts = []
params = []
for arg in self.source_expressions:
try:
arg_sql, arg_params = compiler.compile(arg)
except EmptyResultSet:
empty_result_set_value = getattr(arg, 'empty_result_set_value', NotImplemented)
if empty_result_set_value is NotImplemented:
raise
arg_sql, arg_params = compiler.compile(Value(empty_result_set_value))
sql_parts.append(arg_sql)
params.extend(arg_params)
data = {**self.extra, **extra_context}
# Use the first supplied value in this order: the parameter to this
# method, a value supplied in __init__()'s **extra (the value in
# `data`), or the value defined on the class.
if function is not None:
data['function'] = function
else:
data.setdefault('function', self.function)
template = template or data.get('template', self.template)
arg_joiner = arg_joiner or data.get('arg_joiner', self.arg_joiner)
data['expressions'] = data['field'] = arg_joiner.join(sql_parts)
return template % data, params
def copy(self):
copy = super().copy()
copy.source_expressions = self.source_expressions[:]
copy.extra = self.extra.copy()
return copy
@deconstructible(path='django.db.models.Value')
class Value(SQLiteNumericMixin, Expression):
"""Represent a wrapped value as a node within an expression."""
# Provide a default value for `for_save` in order to allow unresolved
# instances to be compiled until a decision is taken in #25425.
for_save = False
def __init__(self, value, output_field=None):
"""
Arguments:
* value: the value this expression represents. The value will be
added into the sql parameter list and properly quoted.
* output_field: an instance of the model field type that this
expression will return, such as IntegerField() or CharField().
"""
super().__init__(output_field=output_field)
self.value = value
def __repr__(self):
return f'{self.__class__.__name__}({self.value!r})'
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
val = self.value
output_field = self._output_field_or_none
if output_field is not None:
if self.for_save:
val = output_field.get_db_prep_save(val, connection=connection)
else:
val = output_field.get_db_prep_value(val, connection=connection)
if hasattr(output_field, 'get_placeholder'):
return output_field.get_placeholder(val, compiler, connection), [val]
if val is None:
# cx_Oracle does not always convert None to the appropriate
# NULL type (like in case expressions using numbers), so we
# use a literal SQL NULL
return 'NULL', []
return '%s', [val]
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.for_save = for_save
return c
def get_group_by_cols(self, alias=None):
return []
def _resolve_output_field(self):
if isinstance(self.value, str):
return fields.CharField()
if isinstance(self.value, bool):
return fields.BooleanField()
if isinstance(self.value, int):
return fields.IntegerField()
if isinstance(self.value, float):
return fields.FloatField()
if isinstance(self.value, datetime.datetime):
return fields.DateTimeField()
if isinstance(self.value, datetime.date):
return fields.DateField()
if isinstance(self.value, datetime.time):
return fields.TimeField()
if isinstance(self.value, datetime.timedelta):
return fields.DurationField()
if isinstance(self.value, Decimal):
return fields.DecimalField()
if isinstance(self.value, bytes):
return fields.BinaryField()
if isinstance(self.value, UUID):
return fields.UUIDField()
@property
def empty_result_set_value(self):
return self.value
class RawSQL(Expression):
def __init__(self, sql, params, output_field=None):
if output_field is None:
output_field = fields.Field()
self.sql, self.params = sql, params
super().__init__(output_field=output_field)
def __repr__(self):
return "{}({}, {})".format(self.__class__.__name__, self.sql, self.params)
def as_sql(self, compiler, connection):
return '(%s)' % self.sql, self.params
def get_group_by_cols(self, alias=None):
return [self]
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
# Resolve parents fields used in raw SQL.
for parent in query.model._meta.get_parent_list():
for parent_field in parent._meta.local_fields:
_, column_name = parent_field.get_attname_column()
if column_name.lower() in self.sql.lower():
query.resolve_ref(parent_field.name, allow_joins, reuse, summarize)
break
return super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
class Star(Expression):
def __repr__(self):
return "'*'"
def as_sql(self, compiler, connection):
return '*', []
class Col(Expression):
contains_column_references = True
possibly_multivalued = False
def __init__(self, alias, target, output_field=None):
if output_field is None:
output_field = target
super().__init__(output_field=output_field)
self.alias, self.target = alias, target
def __repr__(self):
alias, target = self.alias, self.target
identifiers = (alias, str(target)) if alias else (str(target),)
return '{}({})'.format(self.__class__.__name__, ', '.join(identifiers))
def as_sql(self, compiler, connection):
alias, column = self.alias, self.target.column
identifiers = (alias, column) if alias else (column,)
sql = '.'.join(map(compiler.quote_name_unless_alias, identifiers))
return sql, []
def relabeled_clone(self, relabels):
if self.alias is None:
return self
return self.__class__(relabels.get(self.alias, self.alias), self.target, self.output_field)
def get_group_by_cols(self, alias=None):
return [self]
def get_db_converters(self, connection):
if self.target == self.output_field:
return self.output_field.get_db_converters(connection)
return (self.output_field.get_db_converters(connection) +
self.target.get_db_converters(connection))
class Ref(Expression):
"""
Reference to column alias of the query. For example, Ref('sum_cost') in
qs.annotate(sum_cost=Sum('cost')) query.
"""
def __init__(self, refs, source):
super().__init__()
self.refs, self.source = refs, source
def __repr__(self):
return "{}({}, {})".format(self.__class__.__name__, self.refs, self.source)
def get_source_expressions(self):
return [self.source]
def set_source_expressions(self, exprs):
self.source, = exprs
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
# The sub-expression `source` has already been resolved, as this is
# just a reference to the name of `source`.
return self
def relabeled_clone(self, relabels):
return self
def as_sql(self, compiler, connection):
return connection.ops.quote_name(self.refs), []
def get_group_by_cols(self, alias=None):
return [self]
class ExpressionList(Func):
"""
An expression containing multiple expressions. Can be used to provide a
list of expressions as an argument to another expression, like a partition
clause.
"""
template = '%(expressions)s'
def __init__(self, *expressions, **extra):
if not expressions:
raise ValueError('%s requires at least one expression.' % self.__class__.__name__)
super().__init__(*expressions, **extra)
def __str__(self):
return self.arg_joiner.join(str(arg) for arg in self.source_expressions)
def as_sqlite(self, compiler, connection, **extra_context):
# Casting to numeric is unnecessary.
return self.as_sql(compiler, connection, **extra_context)
class OrderByList(Func):
template = 'ORDER BY %(expressions)s'
def __init__(self, *expressions, **extra):
expressions = (
(
OrderBy(F(expr[1:]), descending=True)
if isinstance(expr, str) and expr[0] == '-'
else expr
)
for expr in expressions
)
super().__init__(*expressions, **extra)
def as_sql(self, *args, **kwargs):
if not self.source_expressions:
return '', ()
return super().as_sql(*args, **kwargs)
@deconstructible(path='django.db.models.ExpressionWrapper')
class ExpressionWrapper(SQLiteNumericMixin, Expression):
"""
An expression that can wrap another expression so that it can provide
extra context to the inner expression, such as the output_field.
"""
def __init__(self, expression, output_field):
super().__init__(output_field=output_field)
self.expression = expression
def set_source_expressions(self, exprs):
self.expression = exprs[0]
def get_source_expressions(self):
return [self.expression]
def get_group_by_cols(self, alias=None):
if isinstance(self.expression, Expression):
expression = self.expression.copy()
expression.output_field = self.output_field
return expression.get_group_by_cols(alias=alias)
# For non-expressions e.g. an SQL WHERE clause, the entire
# `expression` must be included in the GROUP BY clause.
return super().get_group_by_cols()
def as_sql(self, compiler, connection):
return compiler.compile(self.expression)
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.expression)
@deconstructible(path='django.db.models.When')
class When(Expression):
template = 'WHEN %(condition)s THEN %(result)s'
# This isn't a complete conditional expression, must be used in Case().
conditional = False
def __init__(self, condition=None, then=None, **lookups):
if lookups:
if condition is None:
condition, lookups = Q(**lookups), None
elif getattr(condition, 'conditional', False):
condition, lookups = Q(condition, **lookups), None
if condition is None or not getattr(condition, 'conditional', False) or lookups:
raise TypeError(
'When() supports a Q object, a boolean expression, or lookups '
'as a condition.'
)
if isinstance(condition, Q) and not condition:
raise ValueError("An empty Q() can't be used as a When() condition.")
super().__init__(output_field=None)
self.condition = condition
self.result = self._parse_expressions(then)[0]
def __str__(self):
return "WHEN %r THEN %r" % (self.condition, self.result)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_source_expressions(self):
return [self.condition, self.result]
def set_source_expressions(self, exprs):
self.condition, self.result = exprs
def get_source_fields(self):
# We're only interested in the fields of the result expressions.
return [self.result._output_field_or_none]
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
if hasattr(c.condition, 'resolve_expression'):
c.condition = c.condition.resolve_expression(query, allow_joins, reuse, summarize, False)
c.result = c.result.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
def as_sql(self, compiler, connection, template=None, **extra_context):
connection.ops.check_expression_support(self)
template_params = extra_context
sql_params = []
condition_sql, condition_params = compiler.compile(self.condition)
template_params['condition'] = condition_sql
sql_params.extend(condition_params)
result_sql, result_params = compiler.compile(self.result)
template_params['result'] = result_sql
sql_params.extend(result_params)
template = template or self.template
return template % template_params, sql_params
def get_group_by_cols(self, alias=None):
# This is not a complete expression and cannot be used in GROUP BY.
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
@deconstructible(path='django.db.models.Case')
class Case(SQLiteNumericMixin, Expression):
"""
An SQL searched CASE expression:
CASE
WHEN n > 0
THEN 'positive'
WHEN n < 0
THEN 'negative'
ELSE 'zero'
END
"""
template = 'CASE %(cases)s ELSE %(default)s END'
case_joiner = ' '
def __init__(self, *cases, default=None, output_field=None, **extra):
if not all(isinstance(case, When) for case in cases):
raise TypeError("Positional arguments must all be When objects.")
super().__init__(output_field)
self.cases = list(cases)
self.default = self._parse_expressions(default)[0]
self.extra = extra
def __str__(self):
return "CASE %s, ELSE %r" % (', '.join(str(c) for c in self.cases), self.default)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_source_expressions(self):
return self.cases + [self.default]
def set_source_expressions(self, exprs):
*self.cases, self.default = exprs
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
for pos, case in enumerate(c.cases):
c.cases[pos] = case.resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.default = c.default.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
def copy(self):
c = super().copy()
c.cases = c.cases[:]
return c
def as_sql(self, compiler, connection, template=None, case_joiner=None, **extra_context):
connection.ops.check_expression_support(self)
if not self.cases:
return compiler.compile(self.default)
template_params = {**self.extra, **extra_context}
case_parts = []
sql_params = []
for case in self.cases:
try:
case_sql, case_params = compiler.compile(case)
except EmptyResultSet:
continue
case_parts.append(case_sql)
sql_params.extend(case_params)
default_sql, default_params = compiler.compile(self.default)
if not case_parts:
return default_sql, default_params
case_joiner = case_joiner or self.case_joiner
template_params['cases'] = case_joiner.join(case_parts)
template_params['default'] = default_sql
sql_params.extend(default_params)
template = template or template_params.get('template', self.template)
sql = template % template_params
if self._output_field_or_none is not None:
sql = connection.ops.unification_cast_sql(self.output_field) % sql
return sql, sql_params
def get_group_by_cols(self, alias=None):
if not self.cases:
return self.default.get_group_by_cols(alias)
return super().get_group_by_cols(alias)
class Subquery(BaseExpression, Combinable):
"""
An explicit subquery. It may contain OuterRef() references to the outer
query which will be resolved when it is applied to that query.
"""
template = '(%(subquery)s)'
contains_aggregate = False
empty_result_set_value = None
def __init__(self, queryset, output_field=None, **extra):
# Allow the usage of both QuerySet and sql.Query objects.
self.query = getattr(queryset, 'query', queryset).clone()
self.query.subquery = True
self.extra = extra
super().__init__(output_field)
def get_source_expressions(self):
return [self.query]
def set_source_expressions(self, exprs):
self.query = exprs[0]
def _resolve_output_field(self):
return self.query.output_field
def copy(self):
clone = super().copy()
clone.query = clone.query.clone()
return clone
@property
def external_aliases(self):
return self.query.external_aliases
def get_external_cols(self):
return self.query.get_external_cols()
def as_sql(self, compiler, connection, template=None, query=None, **extra_context):
connection.ops.check_expression_support(self)
template_params = {**self.extra, **extra_context}
query = query or self.query
subquery_sql, sql_params = query.as_sql(compiler, connection)
template_params['subquery'] = subquery_sql[1:-1]
template = template or template_params.get('template', self.template)
sql = template % template_params
return sql, sql_params
def get_group_by_cols(self, alias=None):
# If this expression is referenced by an alias for an explicit GROUP BY
# through values() a reference to this expression and not the
# underlying .query must be returned to ensure external column
# references are not grouped against as well.
if alias:
return [Ref(alias, self)]
return self.query.get_group_by_cols()
class Exists(Subquery):
template = 'EXISTS(%(subquery)s)'
output_field = fields.BooleanField()
def __init__(self, queryset, negated=False, **kwargs):
self.negated = negated
super().__init__(queryset, **kwargs)
def __invert__(self):
clone = self.copy()
clone.negated = not self.negated
return clone
def as_sql(self, compiler, connection, template=None, **extra_context):
query = self.query.exists(using=connection.alias)
sql, params = super().as_sql(
compiler,
connection,
template=template,
query=query,
**extra_context,
)
if self.negated:
sql = 'NOT {}'.format(sql)
return sql, params
def select_format(self, compiler, sql, params):
# Wrap EXISTS() with a CASE WHEN expression if a database backend
# (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
# BY list.
if not compiler.connection.features.supports_boolean_expr_in_select_clause:
sql = 'CASE WHEN {} THEN 1 ELSE 0 END'.format(sql)
return sql, params
@deconstructible(path='django.db.models.OrderBy')
class OrderBy(Expression):
template = '%(expression)s %(ordering)s'
conditional = False
def __init__(self, expression, descending=False, nulls_first=False, nulls_last=False):
if nulls_first and nulls_last:
raise ValueError('nulls_first and nulls_last are mutually exclusive')
self.nulls_first = nulls_first
self.nulls_last = nulls_last
self.descending = descending
if not hasattr(expression, 'resolve_expression'):
raise ValueError('expression must be an expression type')
self.expression = expression
def __repr__(self):
return "{}({}, descending={})".format(
self.__class__.__name__, self.expression, self.descending)
def set_source_expressions(self, exprs):
self.expression = exprs[0]
def get_source_expressions(self):
return [self.expression]
def as_sql(self, compiler, connection, template=None, **extra_context):
template = template or self.template
if connection.features.supports_order_by_nulls_modifier:
if self.nulls_last:
template = '%s NULLS LAST' % template
elif self.nulls_first:
template = '%s NULLS FIRST' % template
else:
if self.nulls_last and not (
self.descending and connection.features.order_by_nulls_first
):
template = '%%(expression)s IS NULL, %s' % template
elif self.nulls_first and not (
not self.descending and connection.features.order_by_nulls_first
):
template = '%%(expression)s IS NOT NULL, %s' % template
connection.ops.check_expression_support(self)
expression_sql, params = compiler.compile(self.expression)
placeholders = {
'expression': expression_sql,
'ordering': 'DESC' if self.descending else 'ASC',
**extra_context,
}
params *= template.count('%(expression)s')
return (template % placeholders).rstrip(), params
def as_oracle(self, compiler, connection):
# Oracle doesn't allow ORDER BY EXISTS() or filters unless it's wrapped
# in a CASE WHEN.
if connection.ops.conditional_expression_supported_in_where_clause(self.expression):
copy = self.copy()
copy.expression = Case(
When(self.expression, then=True),
default=False,
)
return copy.as_sql(compiler, connection)
return self.as_sql(compiler, connection)
def get_group_by_cols(self, alias=None):
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def reverse_ordering(self):
self.descending = not self.descending
if self.nulls_first or self.nulls_last:
self.nulls_first = not self.nulls_first
self.nulls_last = not self.nulls_last
return self
def asc(self):
self.descending = False
def desc(self):
self.descending = True
class Window(SQLiteNumericMixin, Expression):
template = '%(expression)s OVER (%(window)s)'
# Although the main expression may either be an aggregate or an
# expression with an aggregate function, the GROUP BY that will
# be introduced in the query as a result is not desired.
contains_aggregate = False
contains_over_clause = True
filterable = False
def __init__(self, expression, partition_by=None, order_by=None, frame=None, output_field=None):
self.partition_by = partition_by
self.order_by = order_by
self.frame = frame
if not getattr(expression, 'window_compatible', False):
raise ValueError(
"Expression '%s' isn't compatible with OVER clauses." %
expression.__class__.__name__
)
if self.partition_by is not None:
if not isinstance(self.partition_by, (tuple, list)):
self.partition_by = (self.partition_by,)
self.partition_by = ExpressionList(*self.partition_by)
if self.order_by is not None:
if isinstance(self.order_by, (list, tuple)):
self.order_by = OrderByList(*self.order_by)
elif isinstance(self.order_by, (BaseExpression, str)):
self.order_by = OrderByList(self.order_by)
else:
raise ValueError(
'Window.order_by must be either a string reference to a '
'field, an expression, or a list or tuple of them.'
)
super().__init__(output_field=output_field)
self.source_expression = self._parse_expressions(expression)[0]
def _resolve_output_field(self):
return self.source_expression.output_field
def get_source_expressions(self):
return [self.source_expression, self.partition_by, self.order_by, self.frame]
def set_source_expressions(self, exprs):
self.source_expression, self.partition_by, self.order_by, self.frame = exprs
def as_sql(self, compiler, connection, template=None):
connection.ops.check_expression_support(self)
if not connection.features.supports_over_clause:
raise NotSupportedError('This backend does not support window expressions.')
expr_sql, params = compiler.compile(self.source_expression)
window_sql, window_params = [], []
if self.partition_by is not None:
sql_expr, sql_params = self.partition_by.as_sql(
compiler=compiler, connection=connection,
template='PARTITION BY %(expressions)s',
)
window_sql.append(sql_expr)
window_params.extend(sql_params)
if self.order_by is not None:
order_sql, order_params = compiler.compile(self.order_by)
window_sql.append(order_sql)
window_params.extend(order_params)
if self.frame:
frame_sql, frame_params = compiler.compile(self.frame)
window_sql.append(frame_sql)
window_params.extend(frame_params)
params.extend(window_params)
template = template or self.template
return template % {
'expression': expr_sql,
'window': ' '.join(window_sql).strip()
}, params
def as_sqlite(self, compiler, connection):
if isinstance(self.output_field, fields.DecimalField):
# Casting to numeric must be outside of the window expression.
copy = self.copy()
source_expressions = copy.get_source_expressions()
source_expressions[0].output_field = fields.FloatField()
copy.set_source_expressions(source_expressions)
return super(Window, copy).as_sqlite(compiler, connection)
return self.as_sql(compiler, connection)
def __str__(self):
return '{} OVER ({}{}{})'.format(
str(self.source_expression),
'PARTITION BY ' + str(self.partition_by) if self.partition_by else '',
str(self.order_by or ''),
str(self.frame or ''),
)
def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self)
def get_group_by_cols(self, alias=None):
return []
class WindowFrame(Expression):
"""
Model the frame clause in window expressions. There are two types of frame
clauses which are subclasses, however, all processing and validation (by no
means intended to be complete) is done here. Thus, providing an end for a
frame is optional (the default is UNBOUNDED FOLLOWING, which is the last
row in the frame).
"""
template = '%(frame_type)s BETWEEN %(start)s AND %(end)s'
def __init__(self, start=None, end=None):
self.start = Value(start)
self.end = Value(end)
def set_source_expressions(self, exprs):
self.start, self.end = exprs
def get_source_expressions(self):
return [self.start, self.end]
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
start, end = self.window_frame_start_end(connection, self.start.value, self.end.value)
return self.template % {
'frame_type': self.frame_type,
'start': start,
'end': end,
}, []
def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self)
def get_group_by_cols(self, alias=None):
return []
def __str__(self):
if self.start.value is not None and self.start.value < 0:
start = '%d %s' % (abs(self.start.value), connection.ops.PRECEDING)
elif self.start.value is not None and self.start.value == 0:
start = connection.ops.CURRENT_ROW
else:
start = connection.ops.UNBOUNDED_PRECEDING
if self.end.value is not None and self.end.value > 0:
end = '%d %s' % (self.end.value, connection.ops.FOLLOWING)
elif self.end.value is not None and self.end.value == 0:
end = connection.ops.CURRENT_ROW
else:
end = connection.ops.UNBOUNDED_FOLLOWING
return self.template % {
'frame_type': self.frame_type,
'start': start,
'end': end,
}
def window_frame_start_end(self, connection, start, end):
raise NotImplementedError('Subclasses must implement window_frame_start_end().')
class RowRange(WindowFrame):
frame_type = 'ROWS'
def window_frame_start_end(self, connection, start, end):
return connection.ops.window_frame_rows_start_end(start, end)
class ValueRange(WindowFrame):
frame_type = 'RANGE'
def window_frame_start_end(self, connection, start, end):
return connection.ops.window_frame_range_start_end(start, end)
|
740e4ebc3401153afe0283966bd4557283ca251bbd3ca7c1a887189604359800 | from collections import Counter, defaultdict
from functools import partial
from itertools import chain
from operator import attrgetter
from django.db import IntegrityError, connections, transaction
from django.db.models import query_utils, signals, sql
class ProtectedError(IntegrityError):
def __init__(self, msg, protected_objects):
self.protected_objects = protected_objects
super().__init__(msg, protected_objects)
class RestrictedError(IntegrityError):
def __init__(self, msg, restricted_objects):
self.restricted_objects = restricted_objects
super().__init__(msg, restricted_objects)
def CASCADE(collector, field, sub_objs, using):
collector.collect(
sub_objs, source=field.remote_field.model, source_attr=field.name,
nullable=field.null, fail_on_restricted=False,
)
if field.null and not connections[using].features.can_defer_constraint_checks:
collector.add_field_update(field, None, sub_objs)
def PROTECT(collector, field, sub_objs, using):
raise ProtectedError(
"Cannot delete some instances of model '%s' because they are "
"referenced through a protected foreign key: '%s.%s'" % (
field.remote_field.model.__name__, sub_objs[0].__class__.__name__, field.name
),
sub_objs
)
def RESTRICT(collector, field, sub_objs, using):
collector.add_restricted_objects(field, sub_objs)
collector.add_dependency(field.remote_field.model, field.model)
def SET(value):
if callable(value):
def set_on_delete(collector, field, sub_objs, using):
collector.add_field_update(field, value(), sub_objs)
else:
def set_on_delete(collector, field, sub_objs, using):
collector.add_field_update(field, value, sub_objs)
set_on_delete.deconstruct = lambda: ('django.db.models.SET', (value,), {})
return set_on_delete
def SET_NULL(collector, field, sub_objs, using):
collector.add_field_update(field, None, sub_objs)
def SET_DEFAULT(collector, field, sub_objs, using):
collector.add_field_update(field, field.get_default(), sub_objs)
def DO_NOTHING(collector, field, sub_objs, using):
pass
def get_candidate_relations_to_delete(opts):
# The candidate relations are the ones that come from N-1 and 1-1 relations.
# N-N (i.e., many-to-many) relations aren't candidates for deletion.
return (
f for f in opts.get_fields(include_hidden=True)
if f.auto_created and not f.concrete and (f.one_to_one or f.one_to_many)
)
class Collector:
def __init__(self, using, origin=None):
self.using = using
# A Model or QuerySet object.
self.origin = origin
# Initially, {model: {instances}}, later values become lists.
self.data = defaultdict(set)
# {model: {(field, value): {instances}}}
self.field_updates = defaultdict(partial(defaultdict, set))
# {model: {field: {instances}}}
self.restricted_objects = defaultdict(partial(defaultdict, set))
# fast_deletes is a list of queryset-likes that can be deleted without
# fetching the objects into memory.
self.fast_deletes = []
# Tracks deletion-order dependency for databases without transactions
# or ability to defer constraint checks. Only concrete model classes
# should be included, as the dependencies exist only between actual
# database tables; proxy models are represented here by their concrete
# parent.
self.dependencies = defaultdict(set) # {model: {models}}
def add(self, objs, source=None, nullable=False, reverse_dependency=False):
"""
Add 'objs' to the collection of objects to be deleted. If the call is
the result of a cascade, 'source' should be the model that caused it,
and 'nullable' should be set to True if the relation can be null.
Return a list of all objects that were not already collected.
"""
if not objs:
return []
new_objs = []
model = objs[0].__class__
instances = self.data[model]
for obj in objs:
if obj not in instances:
new_objs.append(obj)
instances.update(new_objs)
# Nullable relationships can be ignored -- they are nulled out before
# deleting, and therefore do not affect the order in which objects have
# to be deleted.
if source is not None and not nullable:
self.add_dependency(source, model, reverse_dependency=reverse_dependency)
return new_objs
def add_dependency(self, model, dependency, reverse_dependency=False):
if reverse_dependency:
model, dependency = dependency, model
self.dependencies[model._meta.concrete_model].add(dependency._meta.concrete_model)
self.data.setdefault(dependency, self.data.default_factory())
def add_field_update(self, field, value, objs):
"""
Schedule a field update. 'objs' must be a homogeneous iterable
collection of model instances (e.g. a QuerySet).
"""
if not objs:
return
model = objs[0].__class__
self.field_updates[model][field, value].update(objs)
def add_restricted_objects(self, field, objs):
if objs:
model = objs[0].__class__
self.restricted_objects[model][field].update(objs)
def clear_restricted_objects_from_set(self, model, objs):
if model in self.restricted_objects:
self.restricted_objects[model] = {
field: items - objs
for field, items in self.restricted_objects[model].items()
}
def clear_restricted_objects_from_queryset(self, model, qs):
if model in self.restricted_objects:
objs = set(qs.filter(pk__in=[
obj.pk
for objs in self.restricted_objects[model].values() for obj in objs
]))
self.clear_restricted_objects_from_set(model, objs)
def _has_signal_listeners(self, model):
return (
signals.pre_delete.has_listeners(model) or
signals.post_delete.has_listeners(model)
)
def can_fast_delete(self, objs, from_field=None):
"""
Determine if the objects in the given queryset-like or single object
can be fast-deleted. This can be done if there are no cascades, no
parents and no signal listeners for the object class.
The 'from_field' tells where we are coming from - we need this to
determine if the objects are in fact to be deleted. Allow also
skipping parent -> child -> parent chain preventing fast delete of
the child.
"""
if from_field and from_field.remote_field.on_delete is not CASCADE:
return False
if hasattr(objs, '_meta'):
model = objs._meta.model
elif hasattr(objs, 'model') and hasattr(objs, '_raw_delete'):
model = objs.model
else:
return False
if self._has_signal_listeners(model):
return False
# The use of from_field comes from the need to avoid cascade back to
# parent when parent delete is cascading to child.
opts = model._meta
return (
all(link == from_field for link in opts.concrete_model._meta.parents.values()) and
# Foreign keys pointing to this model.
all(
related.field.remote_field.on_delete is DO_NOTHING
for related in get_candidate_relations_to_delete(opts)
) and (
# Something like generic foreign key.
not any(hasattr(field, 'bulk_related_objects') for field in opts.private_fields)
)
)
def get_del_batches(self, objs, fields):
"""
Return the objs in suitably sized batches for the used connection.
"""
field_names = [field.name for field in fields]
conn_batch_size = max(
connections[self.using].ops.bulk_batch_size(field_names, objs), 1)
if len(objs) > conn_batch_size:
return [objs[i:i + conn_batch_size]
for i in range(0, len(objs), conn_batch_size)]
else:
return [objs]
def collect(self, objs, source=None, nullable=False, collect_related=True,
source_attr=None, reverse_dependency=False, keep_parents=False,
fail_on_restricted=True):
"""
Add 'objs' to the collection of objects to be deleted as well as all
parent instances. 'objs' must be a homogeneous iterable collection of
model instances (e.g. a QuerySet). If 'collect_related' is True,
related objects will be handled by their respective on_delete handler.
If the call is the result of a cascade, 'source' should be the model
that caused it and 'nullable' should be set to True, if the relation
can be null.
If 'reverse_dependency' is True, 'source' will be deleted before the
current model, rather than after. (Needed for cascading to parent
models, the one case in which the cascade follows the forwards
direction of an FK rather than the reverse direction.)
If 'keep_parents' is True, data of parent model's will be not deleted.
If 'fail_on_restricted' is False, error won't be raised even if it's
prohibited to delete such objects due to RESTRICT, that defers
restricted object checking in recursive calls where the top-level call
may need to collect more objects to determine whether restricted ones
can be deleted.
"""
if self.can_fast_delete(objs):
self.fast_deletes.append(objs)
return
new_objs = self.add(objs, source, nullable,
reverse_dependency=reverse_dependency)
if not new_objs:
return
model = new_objs[0].__class__
if not keep_parents:
# Recursively collect concrete model's parent models, but not their
# related objects. These will be found by meta.get_fields()
concrete_model = model._meta.concrete_model
for ptr in concrete_model._meta.parents.values():
if ptr:
parent_objs = [getattr(obj, ptr.name) for obj in new_objs]
self.collect(parent_objs, source=model,
source_attr=ptr.remote_field.related_name,
collect_related=False,
reverse_dependency=True,
fail_on_restricted=False)
if not collect_related:
return
if keep_parents:
parents = set(model._meta.get_parent_list())
model_fast_deletes = defaultdict(list)
protected_objects = defaultdict(list)
for related in get_candidate_relations_to_delete(model._meta):
# Preserve parent reverse relationships if keep_parents=True.
if keep_parents and related.model in parents:
continue
field = related.field
if field.remote_field.on_delete == DO_NOTHING:
continue
related_model = related.related_model
if self.can_fast_delete(related_model, from_field=field):
model_fast_deletes[related_model].append(field)
continue
batches = self.get_del_batches(new_objs, [field])
for batch in batches:
sub_objs = self.related_objects(related_model, [field], batch)
# Non-referenced fields can be deferred if no signal receivers
# are connected for the related model as they'll never be
# exposed to the user. Skip field deferring when some
# relationships are select_related as interactions between both
# features are hard to get right. This should only happen in
# the rare cases where .related_objects is overridden anyway.
if not (sub_objs.query.select_related or self._has_signal_listeners(related_model)):
referenced_fields = set(chain.from_iterable(
(rf.attname for rf in rel.field.foreign_related_fields)
for rel in get_candidate_relations_to_delete(related_model._meta)
))
sub_objs = sub_objs.only(*tuple(referenced_fields))
if sub_objs:
try:
field.remote_field.on_delete(self, field, sub_objs, self.using)
except ProtectedError as error:
key = "'%s.%s'" % (field.model.__name__, field.name)
protected_objects[key] += error.protected_objects
if protected_objects:
raise ProtectedError(
'Cannot delete some instances of model %r because they are '
'referenced through protected foreign keys: %s.' % (
model.__name__,
', '.join(protected_objects),
),
set(chain.from_iterable(protected_objects.values())),
)
for related_model, related_fields in model_fast_deletes.items():
batches = self.get_del_batches(new_objs, related_fields)
for batch in batches:
sub_objs = self.related_objects(related_model, related_fields, batch)
self.fast_deletes.append(sub_objs)
for field in model._meta.private_fields:
if hasattr(field, 'bulk_related_objects'):
# It's something like generic foreign key.
sub_objs = field.bulk_related_objects(new_objs, self.using)
self.collect(sub_objs, source=model, nullable=True, fail_on_restricted=False)
if fail_on_restricted:
# Raise an error if collected restricted objects (RESTRICT) aren't
# candidates for deletion also collected via CASCADE.
for related_model, instances in self.data.items():
self.clear_restricted_objects_from_set(related_model, instances)
for qs in self.fast_deletes:
self.clear_restricted_objects_from_queryset(qs.model, qs)
if self.restricted_objects.values():
restricted_objects = defaultdict(list)
for related_model, fields in self.restricted_objects.items():
for field, objs in fields.items():
if objs:
key = "'%s.%s'" % (related_model.__name__, field.name)
restricted_objects[key] += objs
if restricted_objects:
raise RestrictedError(
'Cannot delete some instances of model %r because '
'they are referenced through restricted foreign keys: '
'%s.' % (
model.__name__,
', '.join(restricted_objects),
),
set(chain.from_iterable(restricted_objects.values())),
)
def related_objects(self, related_model, related_fields, objs):
"""
Get a QuerySet of the related model to objs via related fields.
"""
predicate = query_utils.Q(
*(
(f'{related_field.name}__in', objs)
for related_field in related_fields
),
_connector=query_utils.Q.OR,
)
return related_model._base_manager.using(self.using).filter(predicate)
def instances_with_model(self):
for model, instances in self.data.items():
for obj in instances:
yield model, obj
def sort(self):
sorted_models = []
concrete_models = set()
models = list(self.data)
while len(sorted_models) < len(models):
found = False
for model in models:
if model in sorted_models:
continue
dependencies = self.dependencies.get(model._meta.concrete_model)
if not (dependencies and dependencies.difference(concrete_models)):
sorted_models.append(model)
concrete_models.add(model._meta.concrete_model)
found = True
if not found:
return
self.data = {model: self.data[model] for model in sorted_models}
def delete(self):
# sort instance collections
for model, instances in self.data.items():
self.data[model] = sorted(instances, key=attrgetter("pk"))
# if possible, bring the models in an order suitable for databases that
# don't support transactions or cannot defer constraint checks until the
# end of a transaction.
self.sort()
# number of objects deleted for each model label
deleted_counter = Counter()
# Optimize for the case with a single obj and no dependencies
if len(self.data) == 1 and len(instances) == 1:
instance = list(instances)[0]
if self.can_fast_delete(instance):
with transaction.mark_for_rollback_on_error(self.using):
count = sql.DeleteQuery(model).delete_batch([instance.pk], self.using)
setattr(instance, model._meta.pk.attname, None)
return count, {model._meta.label: count}
with transaction.atomic(using=self.using, savepoint=False):
# send pre_delete signals
for model, obj in self.instances_with_model():
if not model._meta.auto_created:
signals.pre_delete.send(
sender=model, instance=obj, using=self.using,
origin=self.origin,
)
# fast deletes
for qs in self.fast_deletes:
count = qs._raw_delete(using=self.using)
if count:
deleted_counter[qs.model._meta.label] += count
# update fields
for model, instances_for_fieldvalues in self.field_updates.items():
for (field, value), instances in instances_for_fieldvalues.items():
query = sql.UpdateQuery(model)
query.update_batch([obj.pk for obj in instances],
{field.name: value}, self.using)
# reverse instance collections
for instances in self.data.values():
instances.reverse()
# delete instances
for model, instances in self.data.items():
query = sql.DeleteQuery(model)
pk_list = [obj.pk for obj in instances]
count = query.delete_batch(pk_list, self.using)
if count:
deleted_counter[model._meta.label] += count
if not model._meta.auto_created:
for obj in instances:
signals.post_delete.send(
sender=model, instance=obj, using=self.using,
origin=self.origin,
)
# update collected instances
for instances_for_fieldvalues in self.field_updates.values():
for (field, value), instances in instances_for_fieldvalues.items():
for obj in instances:
setattr(obj, field.attname, value)
for model, instances in self.data.items():
for instance in instances:
setattr(instance, model._meta.pk.attname, None)
return sum(deleted_counter.values()), dict(deleted_counter)
|
0c461f93b54d2d711e9c6fce8c1278b8e3d2cf17a8d9ae3fe7363e5b9c3a1862 | import itertools
import math
from django.core.exceptions import EmptyResultSet
from django.db.models.expressions import Case, Expression, Func, Value, When
from django.db.models.fields import (
BooleanField, CharField, DateTimeField, Field, IntegerField, UUIDField,
)
from django.db.models.query_utils import RegisterLookupMixin
from django.utils.datastructures import OrderedSet
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
class Lookup(Expression):
lookup_name = None
prepare_rhs = True
can_use_none_as_rhs = False
def __init__(self, lhs, rhs):
self.lhs, self.rhs = lhs, rhs
self.rhs = self.get_prep_lookup()
self.lhs = self.get_prep_lhs()
if hasattr(self.lhs, 'get_bilateral_transforms'):
bilateral_transforms = self.lhs.get_bilateral_transforms()
else:
bilateral_transforms = []
if bilateral_transforms:
# Warn the user as soon as possible if they are trying to apply
# a bilateral transformation on a nested QuerySet: that won't work.
from django.db.models.sql.query import ( # avoid circular import
Query,
)
if isinstance(rhs, Query):
raise NotImplementedError("Bilateral transformations on nested querysets are not implemented.")
self.bilateral_transforms = bilateral_transforms
def apply_bilateral_transforms(self, value):
for transform in self.bilateral_transforms:
value = transform(value)
return value
def __repr__(self):
return f'{self.__class__.__name__}({self.lhs!r}, {self.rhs!r})'
def batch_process_rhs(self, compiler, connection, rhs=None):
if rhs is None:
rhs = self.rhs
if self.bilateral_transforms:
sqls, sqls_params = [], []
for p in rhs:
value = Value(p, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
sql, sql_params = compiler.compile(value)
sqls.append(sql)
sqls_params.extend(sql_params)
else:
_, params = self.get_db_prep_lookup(rhs, connection)
sqls, sqls_params = ['%s'] * len(params), params
return sqls, sqls_params
def get_source_expressions(self):
if self.rhs_is_direct_value():
return [self.lhs]
return [self.lhs, self.rhs]
def set_source_expressions(self, new_exprs):
if len(new_exprs) == 1:
self.lhs = new_exprs[0]
else:
self.lhs, self.rhs = new_exprs
def get_prep_lookup(self):
if not self.prepare_rhs or hasattr(self.rhs, 'resolve_expression'):
return self.rhs
if hasattr(self.lhs, 'output_field'):
if hasattr(self.lhs.output_field, 'get_prep_value'):
return self.lhs.output_field.get_prep_value(self.rhs)
elif self.rhs_is_direct_value():
return Value(self.rhs)
return self.rhs
def get_prep_lhs(self):
if hasattr(self.lhs, 'resolve_expression'):
return self.lhs
return Value(self.lhs)
def get_db_prep_lookup(self, value, connection):
return ('%s', [value])
def process_lhs(self, compiler, connection, lhs=None):
lhs = lhs or self.lhs
if hasattr(lhs, 'resolve_expression'):
lhs = lhs.resolve_expression(compiler.query)
sql, params = compiler.compile(lhs)
if isinstance(lhs, Lookup):
# Wrapped in parentheses to respect operator precedence.
sql = f'({sql})'
return sql, params
def process_rhs(self, compiler, connection):
value = self.rhs
if self.bilateral_transforms:
if self.rhs_is_direct_value():
# Do not call get_db_prep_lookup here as the value will be
# transformed before being used for lookup
value = Value(value, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
if hasattr(value, 'as_sql'):
sql, params = compiler.compile(value)
# Ensure expression is wrapped in parentheses to respect operator
# precedence but avoid double wrapping as it can be misinterpreted
# on some backends (e.g. subqueries on SQLite).
if sql and sql[0] != '(':
sql = '(%s)' % sql
return sql, params
else:
return self.get_db_prep_lookup(value, connection)
def rhs_is_direct_value(self):
return not hasattr(self.rhs, 'as_sql')
def get_group_by_cols(self, alias=None):
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def as_oracle(self, compiler, connection):
# Oracle doesn't allow EXISTS() and filters to be compared to another
# expression unless they're wrapped in a CASE WHEN.
wrapped = False
exprs = []
for expr in (self.lhs, self.rhs):
if connection.ops.conditional_expression_supported_in_where_clause(expr):
expr = Case(When(expr, then=True), default=False)
wrapped = True
exprs.append(expr)
lookup = type(self)(*exprs) if wrapped else self
return lookup.as_sql(compiler, connection)
@cached_property
def output_field(self):
return BooleanField()
@property
def identity(self):
return self.__class__, self.lhs, self.rhs
def __eq__(self, other):
if not isinstance(other, Lookup):
return NotImplemented
return self.identity == other.identity
def __hash__(self):
return hash(make_hashable(self.identity))
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
c.lhs = self.lhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.rhs = self.rhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
def select_format(self, compiler, sql, params):
# Wrap filters with a CASE WHEN expression if a database backend
# (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
# BY list.
if not compiler.connection.features.supports_boolean_expr_in_select_clause:
sql = f'CASE WHEN {sql} THEN 1 ELSE 0 END'
return sql, params
class Transform(RegisterLookupMixin, Func):
"""
RegisterLookupMixin() is first so that get_lookup() and get_transform()
first examine self and then check output_field.
"""
bilateral = False
arity = 1
@property
def lhs(self):
return self.get_source_expressions()[0]
def get_bilateral_transforms(self):
if hasattr(self.lhs, 'get_bilateral_transforms'):
bilateral_transforms = self.lhs.get_bilateral_transforms()
else:
bilateral_transforms = []
if self.bilateral:
bilateral_transforms.append(self.__class__)
return bilateral_transforms
class BuiltinLookup(Lookup):
def process_lhs(self, compiler, connection, lhs=None):
lhs_sql, params = super().process_lhs(compiler, connection, lhs)
field_internal_type = self.lhs.output_field.get_internal_type()
db_type = self.lhs.output_field.db_type(connection=connection)
lhs_sql = connection.ops.field_cast_sql(
db_type, field_internal_type) % lhs_sql
lhs_sql = connection.ops.lookup_cast(self.lookup_name, field_internal_type) % lhs_sql
return lhs_sql, list(params)
def as_sql(self, compiler, connection):
lhs_sql, params = self.process_lhs(compiler, connection)
rhs_sql, rhs_params = self.process_rhs(compiler, connection)
params.extend(rhs_params)
rhs_sql = self.get_rhs_op(connection, rhs_sql)
return '%s %s' % (lhs_sql, rhs_sql), params
def get_rhs_op(self, connection, rhs):
return connection.operators[self.lookup_name] % rhs
class FieldGetDbPrepValueMixin:
"""
Some lookups require Field.get_db_prep_value() to be called on their
inputs.
"""
get_db_prep_lookup_value_is_iterable = False
def get_db_prep_lookup(self, value, connection):
# For relational fields, use the 'target_field' attribute of the
# output_field.
field = getattr(self.lhs.output_field, 'target_field', None)
get_db_prep_value = getattr(field, 'get_db_prep_value', None) or self.lhs.output_field.get_db_prep_value
return (
'%s',
[get_db_prep_value(v, connection, prepared=True) for v in value]
if self.get_db_prep_lookup_value_is_iterable else
[get_db_prep_value(value, connection, prepared=True)]
)
class FieldGetDbPrepValueIterableMixin(FieldGetDbPrepValueMixin):
"""
Some lookups require Field.get_db_prep_value() to be called on each value
in an iterable.
"""
get_db_prep_lookup_value_is_iterable = True
def get_prep_lookup(self):
if hasattr(self.rhs, 'resolve_expression'):
return self.rhs
prepared_values = []
for rhs_value in self.rhs:
if hasattr(rhs_value, 'resolve_expression'):
# An expression will be handled by the database but can coexist
# alongside real values.
pass
elif self.prepare_rhs and hasattr(self.lhs.output_field, 'get_prep_value'):
rhs_value = self.lhs.output_field.get_prep_value(rhs_value)
prepared_values.append(rhs_value)
return prepared_values
def process_rhs(self, compiler, connection):
if self.rhs_is_direct_value():
# rhs should be an iterable of values. Use batch_process_rhs()
# to prepare/transform those values.
return self.batch_process_rhs(compiler, connection)
else:
return super().process_rhs(compiler, connection)
def resolve_expression_parameter(self, compiler, connection, sql, param):
params = [param]
if hasattr(param, 'resolve_expression'):
param = param.resolve_expression(compiler.query)
if hasattr(param, 'as_sql'):
sql, params = compiler.compile(param)
return sql, params
def batch_process_rhs(self, compiler, connection, rhs=None):
pre_processed = super().batch_process_rhs(compiler, connection, rhs)
# The params list may contain expressions which compile to a
# sql/param pair. Zip them to get sql and param pairs that refer to the
# same argument and attempt to replace them with the result of
# compiling the param step.
sql, params = zip(*(
self.resolve_expression_parameter(compiler, connection, sql, param)
for sql, param in zip(*pre_processed)
))
params = itertools.chain.from_iterable(params)
return sql, tuple(params)
class PostgresOperatorLookup(FieldGetDbPrepValueMixin, Lookup):
"""Lookup defined by operators on PostgreSQL."""
postgres_operator = None
def as_postgresql(self, compiler, connection):
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
params = tuple(lhs_params) + tuple(rhs_params)
return '%s %s %s' % (lhs, self.postgres_operator, rhs), params
@Field.register_lookup
class Exact(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'exact'
def get_prep_lookup(self):
from django.db.models.sql.query import Query # avoid circular import
if isinstance(self.rhs, Query):
if self.rhs.has_limit_one():
if not self.rhs.has_select_fields:
self.rhs.clear_select_clause()
self.rhs.add_fields(['pk'])
else:
raise ValueError(
'The QuerySet value for an exact lookup must be limited to '
'one result using slicing.'
)
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
# Avoid comparison against direct rhs if lhs is a boolean value. That
# turns "boolfield__exact=True" into "WHERE boolean_field" instead of
# "WHERE boolean_field = True" when allowed.
if (
isinstance(self.rhs, bool) and
getattr(self.lhs, 'conditional', False) and
connection.ops.conditional_expression_supported_in_where_clause(self.lhs)
):
lhs_sql, params = self.process_lhs(compiler, connection)
template = '%s' if self.rhs else 'NOT %s'
return template % lhs_sql, params
return super().as_sql(compiler, connection)
@Field.register_lookup
class IExact(BuiltinLookup):
lookup_name = 'iexact'
prepare_rhs = False
def process_rhs(self, qn, connection):
rhs, params = super().process_rhs(qn, connection)
if params:
params[0] = connection.ops.prep_for_iexact_query(params[0])
return rhs, params
@Field.register_lookup
class GreaterThan(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'gt'
@Field.register_lookup
class GreaterThanOrEqual(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'gte'
@Field.register_lookup
class LessThan(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'lt'
@Field.register_lookup
class LessThanOrEqual(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'lte'
class IntegerFieldFloatRounding:
"""
Allow floats to work as query values for IntegerField. Without this, the
decimal portion of the float would always be discarded.
"""
def get_prep_lookup(self):
if isinstance(self.rhs, float):
self.rhs = math.ceil(self.rhs)
return super().get_prep_lookup()
@IntegerField.register_lookup
class IntegerGreaterThanOrEqual(IntegerFieldFloatRounding, GreaterThanOrEqual):
pass
@IntegerField.register_lookup
class IntegerLessThan(IntegerFieldFloatRounding, LessThan):
pass
@Field.register_lookup
class In(FieldGetDbPrepValueIterableMixin, BuiltinLookup):
lookup_name = 'in'
def get_prep_lookup(self):
from django.db.models.sql.query import Query # avoid circular import
if isinstance(self.rhs, Query):
self.rhs.clear_ordering(clear_default=True)
if not self.rhs.has_select_fields:
self.rhs.clear_select_clause()
self.rhs.add_fields(['pk'])
return super().get_prep_lookup()
def process_rhs(self, compiler, connection):
db_rhs = getattr(self.rhs, '_db', None)
if db_rhs is not None and db_rhs != connection.alias:
raise ValueError(
"Subqueries aren't allowed across different databases. Force "
"the inner query to be evaluated using `list(inner_query)`."
)
if self.rhs_is_direct_value():
# Remove None from the list as NULL is never equal to anything.
try:
rhs = OrderedSet(self.rhs)
rhs.discard(None)
except TypeError: # Unhashable items in self.rhs
rhs = [r for r in self.rhs if r is not None]
if not rhs:
raise EmptyResultSet
# rhs should be an iterable; use batch_process_rhs() to
# prepare/transform those values.
sqls, sqls_params = self.batch_process_rhs(compiler, connection, rhs)
placeholder = '(' + ', '.join(sqls) + ')'
return (placeholder, sqls_params)
return super().process_rhs(compiler, connection)
def get_rhs_op(self, connection, rhs):
return 'IN %s' % rhs
def as_sql(self, compiler, connection):
max_in_list_size = connection.ops.max_in_list_size()
if self.rhs_is_direct_value() and max_in_list_size and len(self.rhs) > max_in_list_size:
return self.split_parameter_list_as_sql(compiler, connection)
return super().as_sql(compiler, connection)
def split_parameter_list_as_sql(self, compiler, connection):
# This is a special case for databases which limit the number of
# elements which can appear in an 'IN' clause.
max_in_list_size = connection.ops.max_in_list_size()
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.batch_process_rhs(compiler, connection)
in_clause_elements = ['(']
params = []
for offset in range(0, len(rhs_params), max_in_list_size):
if offset > 0:
in_clause_elements.append(' OR ')
in_clause_elements.append('%s IN (' % lhs)
params.extend(lhs_params)
sqls = rhs[offset: offset + max_in_list_size]
sqls_params = rhs_params[offset: offset + max_in_list_size]
param_group = ', '.join(sqls)
in_clause_elements.append(param_group)
in_clause_elements.append(')')
params.extend(sqls_params)
in_clause_elements.append(')')
return ''.join(in_clause_elements), params
class PatternLookup(BuiltinLookup):
param_pattern = '%%%s%%'
prepare_rhs = False
def get_rhs_op(self, connection, rhs):
# Assume we are in startswith. We need to produce SQL like:
# col LIKE %s, ['thevalue%']
# For python values we can (and should) do that directly in Python,
# but if the value is for example reference to other column, then
# we need to add the % pattern match to the lookup by something like
# col LIKE othercol || '%%'
# So, for Python values we don't need any special pattern, but for
# SQL reference values or SQL transformations we need the correct
# pattern added.
if hasattr(self.rhs, 'as_sql') or self.bilateral_transforms:
pattern = connection.pattern_ops[self.lookup_name].format(connection.pattern_esc)
return pattern.format(rhs)
else:
return super().get_rhs_op(connection, rhs)
def process_rhs(self, qn, connection):
rhs, params = super().process_rhs(qn, connection)
if self.rhs_is_direct_value() and params and not self.bilateral_transforms:
params[0] = self.param_pattern % connection.ops.prep_for_like_query(params[0])
return rhs, params
@Field.register_lookup
class Contains(PatternLookup):
lookup_name = 'contains'
@Field.register_lookup
class IContains(Contains):
lookup_name = 'icontains'
@Field.register_lookup
class StartsWith(PatternLookup):
lookup_name = 'startswith'
param_pattern = '%s%%'
@Field.register_lookup
class IStartsWith(StartsWith):
lookup_name = 'istartswith'
@Field.register_lookup
class EndsWith(PatternLookup):
lookup_name = 'endswith'
param_pattern = '%%%s'
@Field.register_lookup
class IEndsWith(EndsWith):
lookup_name = 'iendswith'
@Field.register_lookup
class Range(FieldGetDbPrepValueIterableMixin, BuiltinLookup):
lookup_name = 'range'
def get_rhs_op(self, connection, rhs):
return "BETWEEN %s AND %s" % (rhs[0], rhs[1])
@Field.register_lookup
class IsNull(BuiltinLookup):
lookup_name = 'isnull'
prepare_rhs = False
def as_sql(self, compiler, connection):
if not isinstance(self.rhs, bool):
raise ValueError(
'The QuerySet value for an isnull lookup must be True or '
'False.'
)
sql, params = compiler.compile(self.lhs)
if self.rhs:
return "%s IS NULL" % sql, params
else:
return "%s IS NOT NULL" % sql, params
@Field.register_lookup
class Regex(BuiltinLookup):
lookup_name = 'regex'
prepare_rhs = False
def as_sql(self, compiler, connection):
if self.lookup_name in connection.operators:
return super().as_sql(compiler, connection)
else:
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
sql_template = connection.ops.regex_lookup(self.lookup_name)
return sql_template % (lhs, rhs), lhs_params + rhs_params
@Field.register_lookup
class IRegex(Regex):
lookup_name = 'iregex'
class YearLookup(Lookup):
def year_lookup_bounds(self, connection, year):
from django.db.models.functions import ExtractIsoYear
iso_year = isinstance(self.lhs, ExtractIsoYear)
output_field = self.lhs.lhs.output_field
if isinstance(output_field, DateTimeField):
bounds = connection.ops.year_lookup_bounds_for_datetime_field(
year, iso_year=iso_year,
)
else:
bounds = connection.ops.year_lookup_bounds_for_date_field(
year, iso_year=iso_year,
)
return bounds
def as_sql(self, compiler, connection):
# Avoid the extract operation if the rhs is a direct value to allow
# indexes to be used.
if self.rhs_is_direct_value():
# Skip the extract part by directly using the originating field,
# that is self.lhs.lhs.
lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
rhs_sql, _ = self.process_rhs(compiler, connection)
rhs_sql = self.get_direct_rhs_sql(connection, rhs_sql)
start, finish = self.year_lookup_bounds(connection, self.rhs)
params.extend(self.get_bound_params(start, finish))
return '%s %s' % (lhs_sql, rhs_sql), params
return super().as_sql(compiler, connection)
def get_direct_rhs_sql(self, connection, rhs):
return connection.operators[self.lookup_name] % rhs
def get_bound_params(self, start, finish):
raise NotImplementedError(
'subclasses of YearLookup must provide a get_bound_params() method'
)
class YearExact(YearLookup, Exact):
def get_direct_rhs_sql(self, connection, rhs):
return 'BETWEEN %s AND %s'
def get_bound_params(self, start, finish):
return (start, finish)
class YearGt(YearLookup, GreaterThan):
def get_bound_params(self, start, finish):
return (finish,)
class YearGte(YearLookup, GreaterThanOrEqual):
def get_bound_params(self, start, finish):
return (start,)
class YearLt(YearLookup, LessThan):
def get_bound_params(self, start, finish):
return (start,)
class YearLte(YearLookup, LessThanOrEqual):
def get_bound_params(self, start, finish):
return (finish,)
class UUIDTextMixin:
"""
Strip hyphens from a value when filtering a UUIDField on backends without
a native datatype for UUID.
"""
def process_rhs(self, qn, connection):
if not connection.features.has_native_uuid_field:
from django.db.models.functions import Replace
if self.rhs_is_direct_value():
self.rhs = Value(self.rhs)
self.rhs = Replace(self.rhs, Value('-'), Value(''), output_field=CharField())
rhs, params = super().process_rhs(qn, connection)
return rhs, params
@UUIDField.register_lookup
class UUIDIExact(UUIDTextMixin, IExact):
pass
@UUIDField.register_lookup
class UUIDContains(UUIDTextMixin, Contains):
pass
@UUIDField.register_lookup
class UUIDIContains(UUIDTextMixin, IContains):
pass
@UUIDField.register_lookup
class UUIDStartsWith(UUIDTextMixin, StartsWith):
pass
@UUIDField.register_lookup
class UUIDIStartsWith(UUIDTextMixin, IStartsWith):
pass
@UUIDField.register_lookup
class UUIDEndsWith(UUIDTextMixin, EndsWith):
pass
@UUIDField.register_lookup
class UUIDIEndsWith(UUIDTextMixin, IEndsWith):
pass
|
56199aa348c10e8f1fbcee280bd60fd6c279b58b2672b83df3c59c4c0a9b58ca | """
Helpers to manipulate deferred DDL statements that might need to be adjusted or
discarded within when executing a migration.
"""
from copy import deepcopy
class Reference:
"""Base class that defines the reference interface."""
def references_table(self, table):
"""
Return whether or not this instance references the specified table.
"""
return False
def references_column(self, table, column):
"""
Return whether or not this instance references the specified column.
"""
return False
def rename_table_references(self, old_table, new_table):
"""
Rename all references to the old_name to the new_table.
"""
pass
def rename_column_references(self, table, old_column, new_column):
"""
Rename all references to the old_column to the new_column.
"""
pass
def __repr__(self):
return '<%s %r>' % (self.__class__.__name__, str(self))
def __str__(self):
raise NotImplementedError('Subclasses must define how they should be converted to string.')
class Table(Reference):
"""Hold a reference to a table."""
def __init__(self, table, quote_name):
self.table = table
self.quote_name = quote_name
def references_table(self, table):
return self.table == table
def rename_table_references(self, old_table, new_table):
if self.table == old_table:
self.table = new_table
def __str__(self):
return self.quote_name(self.table)
class TableColumns(Table):
"""Base class for references to multiple columns of a table."""
def __init__(self, table, columns):
self.table = table
self.columns = columns
def references_column(self, table, column):
return self.table == table and column in self.columns
def rename_column_references(self, table, old_column, new_column):
if self.table == table:
for index, column in enumerate(self.columns):
if column == old_column:
self.columns[index] = new_column
class Columns(TableColumns):
"""Hold a reference to one or many columns."""
def __init__(self, table, columns, quote_name, col_suffixes=()):
self.quote_name = quote_name
self.col_suffixes = col_suffixes
super().__init__(table, columns)
def __str__(self):
def col_str(column, idx):
col = self.quote_name(column)
try:
suffix = self.col_suffixes[idx]
if suffix:
col = '{} {}'.format(col, suffix)
except IndexError:
pass
return col
return ', '.join(col_str(column, idx) for idx, column in enumerate(self.columns))
class IndexName(TableColumns):
"""Hold a reference to an index name."""
def __init__(self, table, columns, suffix, create_index_name):
self.suffix = suffix
self.create_index_name = create_index_name
super().__init__(table, columns)
def __str__(self):
return self.create_index_name(self.table, self.columns, self.suffix)
class IndexColumns(Columns):
def __init__(self, table, columns, quote_name, col_suffixes=(), opclasses=()):
self.opclasses = opclasses
super().__init__(table, columns, quote_name, col_suffixes)
def __str__(self):
def col_str(column, idx):
# Index.__init__() guarantees that self.opclasses is the same
# length as self.columns.
col = '{} {}'.format(self.quote_name(column), self.opclasses[idx])
try:
suffix = self.col_suffixes[idx]
if suffix:
col = '{} {}'.format(col, suffix)
except IndexError:
pass
return col
return ', '.join(col_str(column, idx) for idx, column in enumerate(self.columns))
class ForeignKeyName(TableColumns):
"""Hold a reference to a foreign key name."""
def __init__(self, from_table, from_columns, to_table, to_columns, suffix_template, create_fk_name):
self.to_reference = TableColumns(to_table, to_columns)
self.suffix_template = suffix_template
self.create_fk_name = create_fk_name
super().__init__(from_table, from_columns,)
def references_table(self, table):
return super().references_table(table) or self.to_reference.references_table(table)
def references_column(self, table, column):
return (
super().references_column(table, column) or
self.to_reference.references_column(table, column)
)
def rename_table_references(self, old_table, new_table):
super().rename_table_references(old_table, new_table)
self.to_reference.rename_table_references(old_table, new_table)
def rename_column_references(self, table, old_column, new_column):
super().rename_column_references(table, old_column, new_column)
self.to_reference.rename_column_references(table, old_column, new_column)
def __str__(self):
suffix = self.suffix_template % {
'to_table': self.to_reference.table,
'to_column': self.to_reference.columns[0],
}
return self.create_fk_name(self.table, self.columns, suffix)
class Statement(Reference):
"""
Statement template and formatting parameters container.
Allows keeping a reference to a statement without interpolating identifiers
that might have to be adjusted if they're referencing a table or column
that is removed
"""
def __init__(self, template, **parts):
self.template = template
self.parts = parts
def references_table(self, table):
return any(
hasattr(part, 'references_table') and part.references_table(table)
for part in self.parts.values()
)
def references_column(self, table, column):
return any(
hasattr(part, 'references_column') and part.references_column(table, column)
for part in self.parts.values()
)
def rename_table_references(self, old_table, new_table):
for part in self.parts.values():
if hasattr(part, 'rename_table_references'):
part.rename_table_references(old_table, new_table)
def rename_column_references(self, table, old_column, new_column):
for part in self.parts.values():
if hasattr(part, 'rename_column_references'):
part.rename_column_references(table, old_column, new_column)
def __str__(self):
return self.template % self.parts
class Expressions(TableColumns):
def __init__(self, table, expressions, compiler, quote_value):
self.compiler = compiler
self.expressions = expressions
self.quote_value = quote_value
columns = [col.target.column for col in self.compiler.query._gen_cols([self.expressions])]
super().__init__(table, columns)
def rename_table_references(self, old_table, new_table):
if self.table != old_table:
return
self.expressions = self.expressions.relabeled_clone({old_table: new_table})
super().rename_table_references(old_table, new_table)
def rename_column_references(self, table, old_column, new_column):
if self.table != table:
return
expressions = deepcopy(self.expressions)
self.columns = []
for col in self.compiler.query._gen_cols([expressions]):
if col.target.column == old_column:
col.target.column = new_column
self.columns.append(col.target.column)
self.expressions = expressions
def __str__(self):
sql, params = self.compiler.compile(self.expressions)
params = map(self.quote_value, params)
return sql % tuple(params)
|
c3885f6beae9670a800fde9a6940cd889f22d80628e32b1b63a784c63b8727b7 | import datetime
import decimal
import functools
import logging
import time
from contextlib import contextmanager
from django.db import NotSupportedError
from django.utils.crypto import md5
from django.utils.dateparse import parse_time
logger = logging.getLogger('django.db.backends')
class CursorWrapper:
def __init__(self, cursor, db):
self.cursor = cursor
self.db = db
WRAP_ERROR_ATTRS = frozenset(['fetchone', 'fetchmany', 'fetchall', 'nextset'])
def __getattr__(self, attr):
cursor_attr = getattr(self.cursor, attr)
if attr in CursorWrapper.WRAP_ERROR_ATTRS:
return self.db.wrap_database_errors(cursor_attr)
else:
return cursor_attr
def __iter__(self):
with self.db.wrap_database_errors:
yield from self.cursor
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
# Close instead of passing through to avoid backend-specific behavior
# (#17671). Catch errors liberally because errors in cleanup code
# aren't useful.
try:
self.close()
except self.db.Database.Error:
pass
# The following methods cannot be implemented in __getattr__, because the
# code must run when the method is invoked, not just when it is accessed.
def callproc(self, procname, params=None, kparams=None):
# Keyword parameters for callproc aren't supported in PEP 249, but the
# database driver may support them (e.g. cx_Oracle).
if kparams is not None and not self.db.features.supports_callproc_kwargs:
raise NotSupportedError(
'Keyword parameters for callproc are not supported on this '
'database backend.'
)
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
if params is None and kparams is None:
return self.cursor.callproc(procname)
elif kparams is None:
return self.cursor.callproc(procname, params)
else:
params = params or ()
return self.cursor.callproc(procname, params, kparams)
def execute(self, sql, params=None):
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
def executemany(self, sql, param_list):
return self._execute_with_wrappers(sql, param_list, many=True, executor=self._executemany)
def _execute_with_wrappers(self, sql, params, many, executor):
context = {'connection': self.db, 'cursor': self}
for wrapper in reversed(self.db.execute_wrappers):
executor = functools.partial(wrapper, executor)
return executor(sql, params, many, context)
def _execute(self, sql, params, *ignored_wrapper_args):
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
if params is None:
# params default might be backend specific.
return self.cursor.execute(sql)
else:
return self.cursor.execute(sql, params)
def _executemany(self, sql, param_list, *ignored_wrapper_args):
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
return self.cursor.executemany(sql, param_list)
class CursorDebugWrapper(CursorWrapper):
# XXX callproc isn't instrumented at this time.
def execute(self, sql, params=None):
with self.debug_sql(sql, params, use_last_executed_query=True):
return super().execute(sql, params)
def executemany(self, sql, param_list):
with self.debug_sql(sql, param_list, many=True):
return super().executemany(sql, param_list)
@contextmanager
def debug_sql(self, sql=None, params=None, use_last_executed_query=False, many=False):
start = time.monotonic()
try:
yield
finally:
stop = time.monotonic()
duration = stop - start
if use_last_executed_query:
sql = self.db.ops.last_executed_query(self.cursor, sql, params)
try:
times = len(params) if many else ''
except TypeError:
# params could be an iterator.
times = '?'
self.db.queries_log.append({
'sql': '%s times: %s' % (times, sql) if many else sql,
'time': '%.3f' % duration,
})
logger.debug(
'(%.3f) %s; args=%s; alias=%s',
duration,
sql,
params,
self.db.alias,
extra={'duration': duration, 'sql': sql, 'params': params, 'alias': self.db.alias},
)
def split_tzname_delta(tzname):
"""
Split a time zone name into a 3-tuple of (name, sign, offset).
"""
for sign in ['+', '-']:
if sign in tzname:
name, offset = tzname.rsplit(sign, 1)
if offset and parse_time(offset):
return name, sign, offset
return tzname, None, None
###############################################
# Converters from database (string) to Python #
###############################################
def typecast_date(s):
return datetime.date(*map(int, s.split('-'))) if s else None # return None if s is null
def typecast_time(s): # does NOT store time zone information
if not s:
return None
hour, minutes, seconds = s.split(':')
if '.' in seconds: # check whether seconds have a fractional part
seconds, microseconds = seconds.split('.')
else:
microseconds = '0'
return datetime.time(int(hour), int(minutes), int(seconds), int((microseconds + '000000')[:6]))
def typecast_timestamp(s): # does NOT store time zone information
# "2005-07-29 15:48:00.590358-05"
# "2005-07-29 09:56:00-05"
if not s:
return None
if ' ' not in s:
return typecast_date(s)
d, t = s.split()
# Remove timezone information.
if '-' in t:
t, _ = t.split('-', 1)
elif '+' in t:
t, _ = t.split('+', 1)
dates = d.split('-')
times = t.split(':')
seconds = times[2]
if '.' in seconds: # check whether seconds have a fractional part
seconds, microseconds = seconds.split('.')
else:
microseconds = '0'
return datetime.datetime(
int(dates[0]), int(dates[1]), int(dates[2]),
int(times[0]), int(times[1]), int(seconds),
int((microseconds + '000000')[:6])
)
###############################################
# Converters from Python to database (string) #
###############################################
def split_identifier(identifier):
"""
Split an SQL identifier into a two element tuple of (namespace, name).
The identifier could be a table, column, or sequence name might be prefixed
by a namespace.
"""
try:
namespace, name = identifier.split('"."')
except ValueError:
namespace, name = '', identifier
return namespace.strip('"'), name.strip('"')
def truncate_name(identifier, length=None, hash_len=4):
"""
Shorten an SQL identifier to a repeatable mangled version with the given
length.
If a quote stripped name contains a namespace, e.g. USERNAME"."TABLE,
truncate the table portion only.
"""
namespace, name = split_identifier(identifier)
if length is None or len(name) <= length:
return identifier
digest = names_digest(name, length=hash_len)
return '%s%s%s' % ('%s"."' % namespace if namespace else '', name[:length - hash_len], digest)
def names_digest(*args, length):
"""
Generate a 32-bit digest of a set of arguments that can be used to shorten
identifying names.
"""
h = md5(usedforsecurity=False)
for arg in args:
h.update(arg.encode())
return h.hexdigest()[:length]
def format_number(value, max_digits, decimal_places):
"""
Format a number into a string with the requisite number of digits and
decimal places.
"""
if value is None:
return None
context = decimal.getcontext().copy()
if max_digits is not None:
context.prec = max_digits
if decimal_places is not None:
value = value.quantize(decimal.Decimal(1).scaleb(-decimal_places), context=context)
else:
context.traps[decimal.Rounded] = 1
value = context.create_decimal(value)
return "{:f}".format(value)
def strip_quotes(table_name):
"""
Strip quotes off of quoted table names to make them safe for use in index
names, sequence names, etc. For example '"USER"."TABLE"' (an Oracle naming
scheme) becomes 'USER"."TABLE'.
"""
has_quotes = table_name.startswith('"') and table_name.endswith('"')
return table_name[1:-1] if has_quotes else table_name
|
f1c69e047761188cebed0ebeaa7484c032c951c2294f661f39ea784c71cbbceb | from django.db import models
from django.db.migrations.operations.base import Operation
from django.db.migrations.state import ModelState
from django.db.migrations.utils import field_references, resolve_relation
from django.db.models.options import normalize_together
from django.utils.functional import cached_property
from .fields import (
AddField, AlterField, FieldOperation, RemoveField, RenameField,
)
def _check_for_duplicates(arg_name, objs):
used_vals = set()
for val in objs:
if val in used_vals:
raise ValueError(
"Found duplicate value %s in CreateModel %s argument." % (val, arg_name)
)
used_vals.add(val)
class ModelOperation(Operation):
def __init__(self, name):
self.name = name
@cached_property
def name_lower(self):
return self.name.lower()
def references_model(self, name, app_label):
return name.lower() == self.name_lower
def reduce(self, operation, app_label):
return (
super().reduce(operation, app_label) or
self.can_reduce_through(operation, app_label)
)
def can_reduce_through(self, operation, app_label):
return not operation.references_model(self.name, app_label)
class CreateModel(ModelOperation):
"""Create a model's table."""
serialization_expand_args = ['fields', 'options', 'managers']
def __init__(self, name, fields, options=None, bases=None, managers=None):
self.fields = fields
self.options = options or {}
self.bases = bases or (models.Model,)
self.managers = managers or []
super().__init__(name)
# Sanity-check that there are no duplicated field names, bases, or
# manager names
_check_for_duplicates('fields', (name for name, _ in self.fields))
_check_for_duplicates('bases', (
base._meta.label_lower if hasattr(base, '_meta') else
base.lower() if isinstance(base, str) else base
for base in self.bases
))
_check_for_duplicates('managers', (name for name, _ in self.managers))
def deconstruct(self):
kwargs = {
'name': self.name,
'fields': self.fields,
}
if self.options:
kwargs['options'] = self.options
if self.bases and self.bases != (models.Model,):
kwargs['bases'] = self.bases
if self.managers and self.managers != [('objects', models.Manager())]:
kwargs['managers'] = self.managers
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.add_model(ModelState(
app_label,
self.name,
list(self.fields),
dict(self.options),
tuple(self.bases),
list(self.managers),
))
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def describe(self):
return "Create %smodel %s" % ("proxy " if self.options.get("proxy", False) else "", self.name)
@property
def migration_name_fragment(self):
return self.name_lower
def references_model(self, name, app_label):
name_lower = name.lower()
if name_lower == self.name_lower:
return True
# Check we didn't inherit from the model
reference_model_tuple = (app_label, name_lower)
for base in self.bases:
if (base is not models.Model and isinstance(base, (models.base.ModelBase, str)) and
resolve_relation(base, app_label) == reference_model_tuple):
return True
# Check we have no FKs/M2Ms with it
for _name, field in self.fields:
if field_references((app_label, self.name_lower), field, reference_model_tuple):
return True
return False
def reduce(self, operation, app_label):
if (isinstance(operation, DeleteModel) and
self.name_lower == operation.name_lower and
not self.options.get("proxy", False)):
return []
elif isinstance(operation, RenameModel) and self.name_lower == operation.old_name_lower:
return [
CreateModel(
operation.new_name,
fields=self.fields,
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, AlterModelOptions) and self.name_lower == operation.name_lower:
options = {**self.options, **operation.options}
for key in operation.ALTER_OPTION_KEYS:
if key not in operation.options:
options.pop(key, None)
return [
CreateModel(
self.name,
fields=self.fields,
options=options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, AlterTogetherOptionOperation) and self.name_lower == operation.name_lower:
return [
CreateModel(
self.name,
fields=self.fields,
options={**self.options, **{operation.option_name: operation.option_value}},
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, AlterOrderWithRespectTo) and self.name_lower == operation.name_lower:
return [
CreateModel(
self.name,
fields=self.fields,
options={**self.options, 'order_with_respect_to': operation.order_with_respect_to},
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, FieldOperation) and self.name_lower == operation.model_name_lower:
if isinstance(operation, AddField):
return [
CreateModel(
self.name,
fields=self.fields + [(operation.name, operation.field)],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, AlterField):
return [
CreateModel(
self.name,
fields=[
(n, operation.field if n == operation.name else v)
for n, v in self.fields
],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RemoveField):
options = self.options.copy()
for option_name in ('unique_together', 'index_together'):
option = options.pop(option_name, None)
if option:
option = set(filter(bool, (
tuple(f for f in fields if f != operation.name_lower) for fields in option
)))
if option:
options[option_name] = option
order_with_respect_to = options.get('order_with_respect_to')
if order_with_respect_to == operation.name_lower:
del options['order_with_respect_to']
return [
CreateModel(
self.name,
fields=[
(n, v)
for n, v in self.fields
if n.lower() != operation.name_lower
],
options=options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RenameField):
options = self.options.copy()
for option_name in ('unique_together', 'index_together'):
option = options.get(option_name)
if option:
options[option_name] = {
tuple(operation.new_name if f == operation.old_name else f for f in fields)
for fields in option
}
order_with_respect_to = options.get('order_with_respect_to')
if order_with_respect_to == operation.old_name:
options['order_with_respect_to'] = operation.new_name
return [
CreateModel(
self.name,
fields=[
(operation.new_name if n == operation.old_name else n, v)
for n, v in self.fields
],
options=options,
bases=self.bases,
managers=self.managers,
),
]
return super().reduce(operation, app_label)
class DeleteModel(ModelOperation):
"""Drop a model's table."""
def deconstruct(self):
kwargs = {
'name': self.name,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.remove_model(app_label, self.name_lower)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def references_model(self, name, app_label):
# The deleted model could be referencing the specified model through
# related fields.
return True
def describe(self):
return "Delete model %s" % self.name
@property
def migration_name_fragment(self):
return 'delete_%s' % self.name_lower
class RenameModel(ModelOperation):
"""Rename a model."""
def __init__(self, old_name, new_name):
self.old_name = old_name
self.new_name = new_name
super().__init__(old_name)
@cached_property
def old_name_lower(self):
return self.old_name.lower()
@cached_property
def new_name_lower(self):
return self.new_name.lower()
def deconstruct(self):
kwargs = {
'old_name': self.old_name,
'new_name': self.new_name,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.rename_model(app_label, self.old_name, self.new_name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.new_name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.old_name)
old_db_table = old_model._meta.db_table
new_db_table = new_model._meta.db_table
# Don't alter when a table name is not changed.
if old_db_table == new_db_table:
return
# Move the main table
schema_editor.alter_db_table(new_model, old_db_table, new_db_table)
# Alter the fields pointing to us
for related_object in old_model._meta.related_objects:
if related_object.related_model == old_model:
model = new_model
related_key = (app_label, self.new_name_lower)
else:
model = related_object.related_model
related_key = (
related_object.related_model._meta.app_label,
related_object.related_model._meta.model_name,
)
to_field = to_state.apps.get_model(
*related_key
)._meta.get_field(related_object.field.name)
schema_editor.alter_field(
model,
related_object.field,
to_field,
)
# Rename M2M fields whose name is based on this model's name.
fields = zip(old_model._meta.local_many_to_many, new_model._meta.local_many_to_many)
for (old_field, new_field) in fields:
# Skip self-referential fields as these are renamed above.
if new_field.model == new_field.related_model or not new_field.remote_field.through._meta.auto_created:
continue
# Rename the M2M table that's based on this model's name.
old_m2m_model = old_field.remote_field.through
new_m2m_model = new_field.remote_field.through
schema_editor.alter_db_table(
new_m2m_model,
old_m2m_model._meta.db_table,
new_m2m_model._meta.db_table,
)
# Rename the column in the M2M table that's based on this
# model's name.
schema_editor.alter_field(
new_m2m_model,
old_m2m_model._meta.get_field(old_model._meta.model_name),
new_m2m_model._meta.get_field(new_model._meta.model_name),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.new_name_lower, self.old_name_lower = self.old_name_lower, self.new_name_lower
self.new_name, self.old_name = self.old_name, self.new_name
self.database_forwards(app_label, schema_editor, from_state, to_state)
self.new_name_lower, self.old_name_lower = self.old_name_lower, self.new_name_lower
self.new_name, self.old_name = self.old_name, self.new_name
def references_model(self, name, app_label):
return (
name.lower() == self.old_name_lower or
name.lower() == self.new_name_lower
)
def describe(self):
return "Rename model %s to %s" % (self.old_name, self.new_name)
@property
def migration_name_fragment(self):
return 'rename_%s_%s' % (self.old_name_lower, self.new_name_lower)
def reduce(self, operation, app_label):
if (isinstance(operation, RenameModel) and
self.new_name_lower == operation.old_name_lower):
return [
RenameModel(
self.old_name,
operation.new_name,
),
]
# Skip `ModelOperation.reduce` as we want to run `references_model`
# against self.new_name.
return (
super(ModelOperation, self).reduce(operation, app_label) or
not operation.references_model(self.new_name, app_label)
)
class ModelOptionOperation(ModelOperation):
def reduce(self, operation, app_label):
if isinstance(operation, (self.__class__, DeleteModel)) and self.name_lower == operation.name_lower:
return [operation]
return super().reduce(operation, app_label)
class AlterModelTable(ModelOptionOperation):
"""Rename a model's table."""
def __init__(self, name, table):
self.table = table
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'table': self.table,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.alter_model_options(app_label, self.name_lower, {'db_table': self.table})
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
# Rename M2M fields whose name is based on this model's db_table
for (old_field, new_field) in zip(old_model._meta.local_many_to_many, new_model._meta.local_many_to_many):
if new_field.remote_field.through._meta.auto_created:
schema_editor.alter_db_table(
new_field.remote_field.through,
old_field.remote_field.through._meta.db_table,
new_field.remote_field.through._meta.db_table,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return "Rename table for %s to %s" % (
self.name,
self.table if self.table is not None else "(default)"
)
@property
def migration_name_fragment(self):
return 'alter_%s_table' % self.name_lower
class AlterTogetherOptionOperation(ModelOptionOperation):
option_name = None
def __init__(self, name, option_value):
if option_value:
option_value = set(normalize_together(option_value))
setattr(self, self.option_name, option_value)
super().__init__(name)
@cached_property
def option_value(self):
return getattr(self, self.option_name)
def deconstruct(self):
kwargs = {
'name': self.name,
self.option_name: self.option_value,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.alter_model_options(
app_label,
self.name_lower,
{self.option_name: self.option_value},
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
alter_together = getattr(schema_editor, 'alter_%s' % self.option_name)
alter_together(
new_model,
getattr(old_model._meta, self.option_name, set()),
getattr(new_model._meta, self.option_name, set()),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_field(self, model_name, name, app_label):
return (
self.references_model(model_name, app_label) and
(
not self.option_value or
any((name in fields) for fields in self.option_value)
)
)
def describe(self):
return "Alter %s for %s (%s constraint(s))" % (self.option_name, self.name, len(self.option_value or ''))
@property
def migration_name_fragment(self):
return 'alter_%s_%s' % (self.name_lower, self.option_name)
def can_reduce_through(self, operation, app_label):
return (
super().can_reduce_through(operation, app_label) or (
isinstance(operation, AlterTogetherOptionOperation) and
type(operation) is not type(self)
)
)
class AlterUniqueTogether(AlterTogetherOptionOperation):
"""
Change the value of unique_together to the target one.
Input value of unique_together must be a set of tuples.
"""
option_name = 'unique_together'
def __init__(self, name, unique_together):
super().__init__(name, unique_together)
class AlterIndexTogether(AlterTogetherOptionOperation):
"""
Change the value of index_together to the target one.
Input value of index_together must be a set of tuples.
"""
option_name = "index_together"
def __init__(self, name, index_together):
super().__init__(name, index_together)
class AlterOrderWithRespectTo(ModelOptionOperation):
"""Represent a change with the order_with_respect_to option."""
option_name = 'order_with_respect_to'
def __init__(self, name, order_with_respect_to):
self.order_with_respect_to = order_with_respect_to
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'order_with_respect_to': self.order_with_respect_to,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.alter_model_options(
app_label,
self.name_lower,
{self.option_name: self.order_with_respect_to},
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.name)
# Remove a field if we need to
if from_model._meta.order_with_respect_to and not to_model._meta.order_with_respect_to:
schema_editor.remove_field(from_model, from_model._meta.get_field("_order"))
# Add a field if we need to (altering the column is untouched as
# it's likely a rename)
elif to_model._meta.order_with_respect_to and not from_model._meta.order_with_respect_to:
field = to_model._meta.get_field("_order")
if not field.has_default():
field.default = 0
schema_editor.add_field(
from_model,
field,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_field(self, model_name, name, app_label):
return (
self.references_model(model_name, app_label) and
(
self.order_with_respect_to is None or
name == self.order_with_respect_to
)
)
def describe(self):
return "Set order_with_respect_to on %s to %s" % (self.name, self.order_with_respect_to)
@property
def migration_name_fragment(self):
return 'alter_%s_order_with_respect_to' % self.name_lower
class AlterModelOptions(ModelOptionOperation):
"""
Set new model options that don't directly affect the database schema
(like verbose_name, permissions, ordering). Python code in migrations
may still need them.
"""
# Model options we want to compare and preserve in an AlterModelOptions op
ALTER_OPTION_KEYS = [
"base_manager_name",
"default_manager_name",
"default_related_name",
"get_latest_by",
"managed",
"ordering",
"permissions",
"default_permissions",
"select_on_save",
"verbose_name",
"verbose_name_plural",
]
def __init__(self, name, options):
self.options = options
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'options': self.options,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.alter_model_options(
app_label,
self.name_lower,
self.options,
self.ALTER_OPTION_KEYS,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
pass
def database_backwards(self, app_label, schema_editor, from_state, to_state):
pass
def describe(self):
return "Change Meta options on %s" % self.name
@property
def migration_name_fragment(self):
return 'alter_%s_options' % self.name_lower
class AlterModelManagers(ModelOptionOperation):
"""Alter the model's managers."""
serialization_expand_args = ['managers']
def __init__(self, name, managers):
self.managers = managers
super().__init__(name)
def deconstruct(self):
return (
self.__class__.__qualname__,
[self.name, self.managers],
{}
)
def state_forwards(self, app_label, state):
state.alter_model_managers(app_label, self.name_lower, self.managers)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
pass
def database_backwards(self, app_label, schema_editor, from_state, to_state):
pass
def describe(self):
return "Change managers on %s" % self.name
@property
def migration_name_fragment(self):
return 'alter_%s_managers' % self.name_lower
class IndexOperation(Operation):
option_name = 'indexes'
@cached_property
def model_name_lower(self):
return self.model_name.lower()
class AddIndex(IndexOperation):
"""Add an index on a model."""
def __init__(self, model_name, index):
self.model_name = model_name
if not index.name:
raise ValueError(
"Indexes passed to AddIndex operations require a name "
"argument. %r doesn't have one." % index
)
self.index = index
def state_forwards(self, app_label, state):
state.add_index(app_label, self.model_name_lower, self.index)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.add_index(model, self.index)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.remove_index(model, self.index)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'index': self.index,
}
return (
self.__class__.__qualname__,
[],
kwargs,
)
def describe(self):
if self.index.expressions:
return 'Create index %s on %s on model %s' % (
self.index.name,
', '.join([str(expression) for expression in self.index.expressions]),
self.model_name,
)
return 'Create index %s on field(s) %s of model %s' % (
self.index.name,
', '.join(self.index.fields),
self.model_name,
)
@property
def migration_name_fragment(self):
return '%s_%s' % (self.model_name_lower, self.index.name.lower())
class RemoveIndex(IndexOperation):
"""Remove an index from a model."""
def __init__(self, model_name, name):
self.model_name = model_name
self.name = name
def state_forwards(self, app_label, state):
state.remove_index(app_label, self.model_name_lower, self.name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
from_model_state = from_state.models[app_label, self.model_name_lower]
index = from_model_state.get_index_by_name(self.name)
schema_editor.remove_index(model, index)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
to_model_state = to_state.models[app_label, self.model_name_lower]
index = to_model_state.get_index_by_name(self.name)
schema_editor.add_index(model, index)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
}
return (
self.__class__.__qualname__,
[],
kwargs,
)
def describe(self):
return 'Remove index %s from %s' % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return 'remove_%s_%s' % (self.model_name_lower, self.name.lower())
class AddConstraint(IndexOperation):
option_name = 'constraints'
def __init__(self, model_name, constraint):
self.model_name = model_name
self.constraint = constraint
def state_forwards(self, app_label, state):
state.add_constraint(app_label, self.model_name_lower, self.constraint)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.add_constraint(model, self.constraint)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.remove_constraint(model, self.constraint)
def deconstruct(self):
return self.__class__.__name__, [], {
'model_name': self.model_name,
'constraint': self.constraint,
}
def describe(self):
return 'Create constraint %s on model %s' % (self.constraint.name, self.model_name)
@property
def migration_name_fragment(self):
return '%s_%s' % (self.model_name_lower, self.constraint.name.lower())
class RemoveConstraint(IndexOperation):
option_name = 'constraints'
def __init__(self, model_name, name):
self.model_name = model_name
self.name = name
def state_forwards(self, app_label, state):
state.remove_constraint(app_label, self.model_name_lower, self.name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
from_model_state = from_state.models[app_label, self.model_name_lower]
constraint = from_model_state.get_constraint_by_name(self.name)
schema_editor.remove_constraint(model, constraint)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
to_model_state = to_state.models[app_label, self.model_name_lower]
constraint = to_model_state.get_constraint_by_name(self.name)
schema_editor.add_constraint(model, constraint)
def deconstruct(self):
return self.__class__.__name__, [], {
'model_name': self.model_name,
'name': self.name,
}
def describe(self):
return 'Remove constraint %s from model %s' % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return 'remove_%s_%s' % (self.model_name_lower, self.name.lower())
|
54cd33fccde4e61666c6b01feb83b06f59a4515a7b6c4a10a5df4fa7dd6a481e | from django.db.migrations.utils import field_references
from django.db.models import NOT_PROVIDED
from django.utils.functional import cached_property
from .base import Operation
class FieldOperation(Operation):
def __init__(self, model_name, name, field=None):
self.model_name = model_name
self.name = name
self.field = field
@cached_property
def model_name_lower(self):
return self.model_name.lower()
@cached_property
def name_lower(self):
return self.name.lower()
def is_same_model_operation(self, operation):
return self.model_name_lower == operation.model_name_lower
def is_same_field_operation(self, operation):
return self.is_same_model_operation(operation) and self.name_lower == operation.name_lower
def references_model(self, name, app_label):
name_lower = name.lower()
if name_lower == self.model_name_lower:
return True
if self.field:
return bool(field_references(
(app_label, self.model_name_lower), self.field, (app_label, name_lower)
))
return False
def references_field(self, model_name, name, app_label):
model_name_lower = model_name.lower()
# Check if this operation locally references the field.
if model_name_lower == self.model_name_lower:
if name == self.name:
return True
elif self.field and hasattr(self.field, 'from_fields') and name in self.field.from_fields:
return True
# Check if this operation remotely references the field.
if self.field is None:
return False
return bool(field_references(
(app_label, self.model_name_lower),
self.field,
(app_label, model_name_lower),
name,
))
def reduce(self, operation, app_label):
return (
super().reduce(operation, app_label) or
not operation.references_field(self.model_name, self.name, app_label)
)
class AddField(FieldOperation):
"""Add a field to a model."""
def __init__(self, model_name, name, field, preserve_default=True):
self.preserve_default = preserve_default
super().__init__(model_name, name, field)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
'field': self.field,
}
if self.preserve_default is not True:
kwargs['preserve_default'] = self.preserve_default
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.add_field(
app_label,
self.model_name_lower,
self.name,
self.field,
self.preserve_default,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
field = to_model._meta.get_field(self.name)
if not self.preserve_default:
field.default = self.field.default
schema_editor.add_field(
from_model,
field,
)
if not self.preserve_default:
field.default = NOT_PROVIDED
def database_backwards(self, app_label, schema_editor, from_state, to_state):
from_model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, from_model):
schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
def describe(self):
return "Add field %s to %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return '%s_%s' % (self.model_name_lower, self.name_lower)
def reduce(self, operation, app_label):
if isinstance(operation, FieldOperation) and self.is_same_field_operation(operation):
if isinstance(operation, AlterField):
return [
AddField(
model_name=self.model_name,
name=operation.name,
field=operation.field,
),
]
elif isinstance(operation, RemoveField):
return []
elif isinstance(operation, RenameField):
return [
AddField(
model_name=self.model_name,
name=operation.new_name,
field=self.field,
),
]
return super().reduce(operation, app_label)
class RemoveField(FieldOperation):
"""Remove a field from a model."""
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
}
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.remove_field(app_label, self.model_name_lower, self.name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
from_model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, from_model):
schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
def database_backwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.add_field(from_model, to_model._meta.get_field(self.name))
def describe(self):
return "Remove field %s from %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return 'remove_%s_%s' % (self.model_name_lower, self.name_lower)
def reduce(self, operation, app_label):
from .models import DeleteModel
if isinstance(operation, DeleteModel) and operation.name_lower == self.model_name_lower:
return [operation]
return super().reduce(operation, app_label)
class AlterField(FieldOperation):
"""
Alter a field's database column (e.g. null, max_length) to the provided
new field.
"""
def __init__(self, model_name, name, field, preserve_default=True):
self.preserve_default = preserve_default
super().__init__(model_name, name, field)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
'field': self.field,
}
if self.preserve_default is not True:
kwargs['preserve_default'] = self.preserve_default
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.alter_field(
app_label,
self.model_name_lower,
self.name,
self.field,
self.preserve_default,
)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
from_field = from_model._meta.get_field(self.name)
to_field = to_model._meta.get_field(self.name)
if not self.preserve_default:
to_field.default = self.field.default
schema_editor.alter_field(from_model, from_field, to_field)
if not self.preserve_default:
to_field.default = NOT_PROVIDED
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.database_forwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return "Alter field %s on %s" % (self.name, self.model_name)
@property
def migration_name_fragment(self):
return 'alter_%s_%s' % (self.model_name_lower, self.name_lower)
def reduce(self, operation, app_label):
if isinstance(operation, RemoveField) and self.is_same_field_operation(operation):
return [operation]
elif (
isinstance(operation, RenameField) and
self.is_same_field_operation(operation) and
self.field.db_column is None
):
return [
operation,
AlterField(
model_name=self.model_name,
name=operation.new_name,
field=self.field,
),
]
return super().reduce(operation, app_label)
class RenameField(FieldOperation):
"""Rename a field on the model. Might affect db_column too."""
def __init__(self, model_name, old_name, new_name):
self.old_name = old_name
self.new_name = new_name
super().__init__(model_name, old_name)
@cached_property
def old_name_lower(self):
return self.old_name.lower()
@cached_property
def new_name_lower(self):
return self.new_name.lower()
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'old_name': self.old_name,
'new_name': self.new_name,
}
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.rename_field(app_label, self.model_name_lower, self.old_name, self.new_name)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.alter_field(
from_model,
from_model._meta.get_field(self.old_name),
to_model._meta.get_field(self.new_name),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.alter_field(
from_model,
from_model._meta.get_field(self.new_name),
to_model._meta.get_field(self.old_name),
)
def describe(self):
return "Rename field %s on %s to %s" % (self.old_name, self.model_name, self.new_name)
@property
def migration_name_fragment(self):
return 'rename_%s_%s_%s' % (
self.old_name_lower,
self.model_name_lower,
self.new_name_lower,
)
def references_field(self, model_name, name, app_label):
return self.references_model(model_name, app_label) and (
name.lower() == self.old_name_lower or
name.lower() == self.new_name_lower
)
def reduce(self, operation, app_label):
if (isinstance(operation, RenameField) and
self.is_same_model_operation(operation) and
self.new_name_lower == operation.old_name_lower):
return [
RenameField(
self.model_name,
self.old_name,
operation.new_name,
),
]
# Skip `FieldOperation.reduce` as we want to run `references_field`
# against self.old_name and self.new_name.
return (
super(FieldOperation, self).reduce(operation, app_label) or
not (
operation.references_field(self.model_name, self.old_name, app_label) or
operation.references_field(self.model_name, self.new_name, app_label)
)
)
|
14435641b15cf2e2872957f0fd76b0266f0bd46d3c77608e335ddb0bf3498d52 | from django.db.models.lookups import (
Exact, GreaterThan, GreaterThanOrEqual, In, IsNull, LessThan,
LessThanOrEqual,
)
class MultiColSource:
contains_aggregate = False
def __init__(self, alias, targets, sources, field):
self.targets, self.sources, self.field, self.alias = targets, sources, field, alias
self.output_field = self.field
def __repr__(self):
return "{}({}, {})".format(
self.__class__.__name__, self.alias, self.field)
def relabeled_clone(self, relabels):
return self.__class__(relabels.get(self.alias, self.alias),
self.targets, self.sources, self.field)
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
def resolve_expression(self, *args, **kwargs):
return self
def get_normalized_value(value, lhs):
from django.db.models import Model
if isinstance(value, Model):
value_list = []
sources = lhs.output_field.path_infos[-1].target_fields
for source in sources:
while not isinstance(value, source.model) and source.remote_field:
source = source.remote_field.model._meta.get_field(source.remote_field.field_name)
try:
value_list.append(getattr(value, source.attname))
except AttributeError:
# A case like Restaurant.objects.filter(place=restaurant_instance),
# where place is a OneToOneField and the primary key of Restaurant.
return (value.pk,)
return tuple(value_list)
if not isinstance(value, tuple):
return (value,)
return value
class RelatedIn(In):
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource):
if self.rhs_is_direct_value():
# If we get here, we are dealing with single-column relations.
self.rhs = [get_normalized_value(val, self.lhs)[0] for val in self.rhs]
# We need to run the related field's get_prep_value(). Consider
# case ForeignKey to IntegerField given value 'abc'. The
# ForeignKey itself doesn't have validation for non-integers,
# so we must run validation using the target field.
if hasattr(self.lhs.output_field, 'path_infos'):
# Run the target field's get_prep_value. We can safely
# assume there is only one as we don't get to the direct
# value branch otherwise.
target_field = self.lhs.output_field.path_infos[-1].target_fields[-1]
self.rhs = [target_field.get_prep_value(v) for v in self.rhs]
elif (
not getattr(self.rhs, 'has_select_fields', True) and
not getattr(self.lhs.field.target_field, 'primary_key', False)
):
self.rhs.clear_select_clause()
if (
getattr(self.lhs.output_field, 'primary_key', False) and
self.lhs.output_field.model == self.rhs.model
):
# A case like
# Restaurant.objects.filter(place__in=restaurant_qs), where
# place is a OneToOneField and the primary key of
# Restaurant.
target_field = self.lhs.field.name
else:
target_field = self.lhs.field.target_field.name
self.rhs.add_fields([target_field], True)
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
# For multicolumn lookups we need to build a multicolumn where clause.
# This clause is either a SubqueryConstraint (for values that need to be compiled to
# SQL) or an OR-combined list of (col1 = val1 AND col2 = val2 AND ...) clauses.
from django.db.models.sql.where import (
AND, OR, SubqueryConstraint, WhereNode,
)
root_constraint = WhereNode(connector=OR)
if self.rhs_is_direct_value():
values = [get_normalized_value(value, self.lhs) for value in self.rhs]
for value in values:
value_constraint = WhereNode()
for source, target, val in zip(self.lhs.sources, self.lhs.targets, value):
lookup_class = target.get_lookup('exact')
lookup = lookup_class(target.get_col(self.lhs.alias, source), val)
value_constraint.add(lookup, AND)
root_constraint.add(value_constraint, OR)
else:
root_constraint.add(
SubqueryConstraint(
self.lhs.alias, [target.column for target in self.lhs.targets],
[source.name for source in self.lhs.sources], self.rhs),
AND)
return root_constraint.as_sql(compiler, connection)
return super().as_sql(compiler, connection)
class RelatedLookupMixin:
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource) and not hasattr(self.rhs, 'resolve_expression'):
# If we get here, we are dealing with single-column relations.
self.rhs = get_normalized_value(self.rhs, self.lhs)[0]
# We need to run the related field's get_prep_value(). Consider case
# ForeignKey to IntegerField given value 'abc'. The ForeignKey itself
# doesn't have validation for non-integers, so we must run validation
# using the target field.
if self.prepare_rhs and hasattr(self.lhs.output_field, 'path_infos'):
# Get the target field. We can safely assume there is only one
# as we don't get to the direct value branch otherwise.
target_field = self.lhs.output_field.path_infos[-1].target_fields[-1]
self.rhs = target_field.get_prep_value(self.rhs)
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
assert self.rhs_is_direct_value()
self.rhs = get_normalized_value(self.rhs, self.lhs)
from django.db.models.sql.where import AND, WhereNode
root_constraint = WhereNode()
for target, source, val in zip(self.lhs.targets, self.lhs.sources, self.rhs):
lookup_class = target.get_lookup(self.lookup_name)
root_constraint.add(
lookup_class(target.get_col(self.lhs.alias, source), val), AND)
return root_constraint.as_sql(compiler, connection)
return super().as_sql(compiler, connection)
class RelatedExact(RelatedLookupMixin, Exact):
pass
class RelatedLessThan(RelatedLookupMixin, LessThan):
pass
class RelatedGreaterThan(RelatedLookupMixin, GreaterThan):
pass
class RelatedGreaterThanOrEqual(RelatedLookupMixin, GreaterThanOrEqual):
pass
class RelatedLessThanOrEqual(RelatedLookupMixin, LessThanOrEqual):
pass
class RelatedIsNull(RelatedLookupMixin, IsNull):
pass
|
db106dbf5f222248c44885c58d2145838055dbcd1a6e202721769f870c252ecc | import collections.abc
import copy
import datetime
import decimal
import math
import operator
import uuid
import warnings
from base64 import b64decode, b64encode
from functools import partialmethod, total_ordering
from django import forms
from django.apps import apps
from django.conf import settings
from django.core import checks, exceptions, validators
from django.db import connection, connections, router
from django.db.models.constants import LOOKUP_SEP
from django.db.models.query_utils import DeferredAttribute, RegisterLookupMixin
from django.utils import timezone
from django.utils.datastructures import DictWrapper
from django.utils.dateparse import (
parse_date, parse_datetime, parse_duration, parse_time,
)
from django.utils.duration import duration_microseconds, duration_string
from django.utils.functional import Promise, cached_property
from django.utils.ipv6 import clean_ipv6_address
from django.utils.itercompat import is_iterable
from django.utils.text import capfirst
from django.utils.translation import gettext_lazy as _
__all__ = [
'AutoField', 'BLANK_CHOICE_DASH', 'BigAutoField', 'BigIntegerField',
'BinaryField', 'BooleanField', 'CharField', 'CommaSeparatedIntegerField',
'DateField', 'DateTimeField', 'DecimalField', 'DurationField',
'EmailField', 'Empty', 'Field', 'FilePathField', 'FloatField',
'GenericIPAddressField', 'IPAddressField', 'IntegerField', 'NOT_PROVIDED',
'NullBooleanField', 'PositiveBigIntegerField', 'PositiveIntegerField',
'PositiveSmallIntegerField', 'SlugField', 'SmallAutoField',
'SmallIntegerField', 'TextField', 'TimeField', 'URLField', 'UUIDField',
]
class Empty:
pass
class NOT_PROVIDED:
pass
# The values to use for "blank" in SelectFields. Will be appended to the start
# of most "choices" lists.
BLANK_CHOICE_DASH = [("", "---------")]
def _load_field(app_label, model_name, field_name):
return apps.get_model(app_label, model_name)._meta.get_field(field_name)
# A guide to Field parameters:
#
# * name: The name of the field specified in the model.
# * attname: The attribute to use on the model object. This is the same as
# "name", except in the case of ForeignKeys, where "_id" is
# appended.
# * db_column: The db_column specified in the model (or None).
# * column: The database column for this field. This is the same as
# "attname", except if db_column is specified.
#
# Code that introspects values, or does other dynamic things, should use
# attname. For example, this gets the primary key value of object "obj":
#
# getattr(obj, opts.pk.attname)
def _empty(of_cls):
new = Empty()
new.__class__ = of_cls
return new
def return_None():
return None
@total_ordering
class Field(RegisterLookupMixin):
"""Base class for all field types"""
# Designates whether empty strings fundamentally are allowed at the
# database level.
empty_strings_allowed = True
empty_values = list(validators.EMPTY_VALUES)
# These track each time a Field instance is created. Used to retain order.
# The auto_creation_counter is used for fields that Django implicitly
# creates, creation_counter is used for all user-specified fields.
creation_counter = 0
auto_creation_counter = -1
default_validators = [] # Default set of validators
default_error_messages = {
'invalid_choice': _('Value %(value)r is not a valid choice.'),
'null': _('This field cannot be null.'),
'blank': _('This field cannot be blank.'),
'unique': _('%(model_name)s with this %(field_label)s '
'already exists.'),
# Translators: The 'lookup_type' is one of 'date', 'year' or 'month'.
# Eg: "Title must be unique for pub_date year"
'unique_for_date': _("%(field_label)s must be unique for "
"%(date_field_label)s %(lookup_type)s."),
}
system_check_deprecated_details = None
system_check_removed_details = None
# Field flags
hidden = False
many_to_many = None
many_to_one = None
one_to_many = None
one_to_one = None
related_model = None
descriptor_class = DeferredAttribute
# Generic field type description, usually overridden by subclasses
def _description(self):
return _('Field of type: %(field_type)s') % {
'field_type': self.__class__.__name__
}
description = property(_description)
def __init__(self, verbose_name=None, name=None, primary_key=False,
max_length=None, unique=False, blank=False, null=False,
db_index=False, rel=None, default=NOT_PROVIDED, editable=True,
serialize=True, unique_for_date=None, unique_for_month=None,
unique_for_year=None, choices=None, help_text='', db_column=None,
db_tablespace=None, auto_created=False, validators=(),
error_messages=None):
self.name = name
self.verbose_name = verbose_name # May be set by set_attributes_from_name
self._verbose_name = verbose_name # Store original for deconstruction
self.primary_key = primary_key
self.max_length, self._unique = max_length, unique
self.blank, self.null = blank, null
self.remote_field = rel
self.is_relation = self.remote_field is not None
self.default = default
self.editable = editable
self.serialize = serialize
self.unique_for_date = unique_for_date
self.unique_for_month = unique_for_month
self.unique_for_year = unique_for_year
if isinstance(choices, collections.abc.Iterator):
choices = list(choices)
self.choices = choices
self.help_text = help_text
self.db_index = db_index
self.db_column = db_column
self._db_tablespace = db_tablespace
self.auto_created = auto_created
# Adjust the appropriate creation counter, and save our local copy.
if auto_created:
self.creation_counter = Field.auto_creation_counter
Field.auto_creation_counter -= 1
else:
self.creation_counter = Field.creation_counter
Field.creation_counter += 1
self._validators = list(validators) # Store for deconstruction later
messages = {}
for c in reversed(self.__class__.__mro__):
messages.update(getattr(c, 'default_error_messages', {}))
messages.update(error_messages or {})
self._error_messages = error_messages # Store for deconstruction later
self.error_messages = messages
def __str__(self):
"""
Return "app_label.model_label.field_name" for fields attached to
models.
"""
if not hasattr(self, 'model'):
return super().__str__()
model = self.model
return '%s.%s' % (model._meta.label, self.name)
def __repr__(self):
"""Display the module, class, and name of the field."""
path = '%s.%s' % (self.__class__.__module__, self.__class__.__qualname__)
name = getattr(self, 'name', None)
if name is not None:
return '<%s: %s>' % (path, name)
return '<%s>' % path
def check(self, **kwargs):
return [
*self._check_field_name(),
*self._check_choices(),
*self._check_db_index(),
*self._check_null_allowed_for_primary_keys(),
*self._check_backend_specific_checks(**kwargs),
*self._check_validators(),
*self._check_deprecation_details(),
]
def _check_field_name(self):
"""
Check if field name is valid, i.e. 1) does not end with an
underscore, 2) does not contain "__" and 3) is not "pk".
"""
if self.name.endswith('_'):
return [
checks.Error(
'Field names must not end with an underscore.',
obj=self,
id='fields.E001',
)
]
elif LOOKUP_SEP in self.name:
return [
checks.Error(
'Field names must not contain "%s".' % LOOKUP_SEP,
obj=self,
id='fields.E002',
)
]
elif self.name == 'pk':
return [
checks.Error(
"'pk' is a reserved word that cannot be used as a field name.",
obj=self,
id='fields.E003',
)
]
else:
return []
@classmethod
def _choices_is_value(cls, value):
return isinstance(value, (str, Promise)) or not is_iterable(value)
def _check_choices(self):
if not self.choices:
return []
if not is_iterable(self.choices) or isinstance(self.choices, str):
return [
checks.Error(
"'choices' must be an iterable (e.g., a list or tuple).",
obj=self,
id='fields.E004',
)
]
choice_max_length = 0
# Expect [group_name, [value, display]]
for choices_group in self.choices:
try:
group_name, group_choices = choices_group
except (TypeError, ValueError):
# Containing non-pairs
break
try:
if not all(
self._choices_is_value(value) and self._choices_is_value(human_name)
for value, human_name in group_choices
):
break
if self.max_length is not None and group_choices:
choice_max_length = max([
choice_max_length,
*(len(value) for value, _ in group_choices if isinstance(value, str)),
])
except (TypeError, ValueError):
# No groups, choices in the form [value, display]
value, human_name = group_name, group_choices
if not self._choices_is_value(value) or not self._choices_is_value(human_name):
break
if self.max_length is not None and isinstance(value, str):
choice_max_length = max(choice_max_length, len(value))
# Special case: choices=['ab']
if isinstance(choices_group, str):
break
else:
if self.max_length is not None and choice_max_length > self.max_length:
return [
checks.Error(
"'max_length' is too small to fit the longest value "
"in 'choices' (%d characters)." % choice_max_length,
obj=self,
id='fields.E009',
),
]
return []
return [
checks.Error(
"'choices' must be an iterable containing "
"(actual value, human readable name) tuples.",
obj=self,
id='fields.E005',
)
]
def _check_db_index(self):
if self.db_index not in (None, True, False):
return [
checks.Error(
"'db_index' must be None, True or False.",
obj=self,
id='fields.E006',
)
]
else:
return []
def _check_null_allowed_for_primary_keys(self):
if (self.primary_key and self.null and
not connection.features.interprets_empty_strings_as_nulls):
# We cannot reliably check this for backends like Oracle which
# consider NULL and '' to be equal (and thus set up
# character-based fields a little differently).
return [
checks.Error(
'Primary keys must not have null=True.',
hint=('Set null=False on the field, or '
'remove primary_key=True argument.'),
obj=self,
id='fields.E007',
)
]
else:
return []
def _check_backend_specific_checks(self, databases=None, **kwargs):
if databases is None:
return []
app_label = self.model._meta.app_label
errors = []
for alias in databases:
if router.allow_migrate(alias, app_label, model_name=self.model._meta.model_name):
errors.extend(connections[alias].validation.check_field(self, **kwargs))
return errors
def _check_validators(self):
errors = []
for i, validator in enumerate(self.validators):
if not callable(validator):
errors.append(
checks.Error(
"All 'validators' must be callable.",
hint=(
"validators[{i}] ({repr}) isn't a function or "
"instance of a validator class.".format(
i=i, repr=repr(validator),
)
),
obj=self,
id='fields.E008',
)
)
return errors
def _check_deprecation_details(self):
if self.system_check_removed_details is not None:
return [
checks.Error(
self.system_check_removed_details.get(
'msg',
'%s has been removed except for support in historical '
'migrations.' % self.__class__.__name__
),
hint=self.system_check_removed_details.get('hint'),
obj=self,
id=self.system_check_removed_details.get('id', 'fields.EXXX'),
)
]
elif self.system_check_deprecated_details is not None:
return [
checks.Warning(
self.system_check_deprecated_details.get(
'msg',
'%s has been deprecated.' % self.__class__.__name__
),
hint=self.system_check_deprecated_details.get('hint'),
obj=self,
id=self.system_check_deprecated_details.get('id', 'fields.WXXX'),
)
]
return []
def get_col(self, alias, output_field=None):
if (
alias == self.model._meta.db_table and
(output_field is None or output_field == self)
):
return self.cached_col
from django.db.models.expressions import Col
return Col(alias, self, output_field)
@cached_property
def cached_col(self):
from django.db.models.expressions import Col
return Col(self.model._meta.db_table, self)
def select_format(self, compiler, sql, params):
"""
Custom format for select clauses. For example, GIS columns need to be
selected as AsText(table.col) on MySQL as the table.col data can't be
used by Django.
"""
return sql, params
def deconstruct(self):
"""
Return enough information to recreate the field as a 4-tuple:
* The name of the field on the model, if contribute_to_class() has
been run.
* The import path of the field, including the class, e.g.
django.db.models.IntegerField. This should be the most portable
version, so less specific may be better.
* A list of positional arguments.
* A dict of keyword arguments.
Note that the positional or keyword arguments must contain values of
the following types (including inner values of collection types):
* None, bool, str, int, float, complex, set, frozenset, list, tuple,
dict
* UUID
* datetime.datetime (naive), datetime.date
* top-level classes, top-level functions - will be referenced by their
full import path
* Storage instances - these have their own deconstruct() method
This is because the values here must be serialized into a text format
(possibly new Python code, possibly JSON) and these are the only types
with encoding handlers defined.
There's no need to return the exact way the field was instantiated this
time, just ensure that the resulting field is the same - prefer keyword
arguments over positional ones, and omit parameters with their default
values.
"""
# Short-form way of fetching all the default parameters
keywords = {}
possibles = {
"verbose_name": None,
"primary_key": False,
"max_length": None,
"unique": False,
"blank": False,
"null": False,
"db_index": False,
"default": NOT_PROVIDED,
"editable": True,
"serialize": True,
"unique_for_date": None,
"unique_for_month": None,
"unique_for_year": None,
"choices": None,
"help_text": '',
"db_column": None,
"db_tablespace": None,
"auto_created": False,
"validators": [],
"error_messages": None,
}
attr_overrides = {
"unique": "_unique",
"error_messages": "_error_messages",
"validators": "_validators",
"verbose_name": "_verbose_name",
"db_tablespace": "_db_tablespace",
}
equals_comparison = {"choices", "validators"}
for name, default in possibles.items():
value = getattr(self, attr_overrides.get(name, name))
# Unroll anything iterable for choices into a concrete list
if name == "choices" and isinstance(value, collections.abc.Iterable):
value = list(value)
# Do correct kind of comparison
if name in equals_comparison:
if value != default:
keywords[name] = value
else:
if value is not default:
keywords[name] = value
# Work out path - we shorten it for known Django core fields
path = "%s.%s" % (self.__class__.__module__, self.__class__.__qualname__)
if path.startswith("django.db.models.fields.related"):
path = path.replace("django.db.models.fields.related", "django.db.models")
elif path.startswith("django.db.models.fields.files"):
path = path.replace("django.db.models.fields.files", "django.db.models")
elif path.startswith('django.db.models.fields.json'):
path = path.replace('django.db.models.fields.json', 'django.db.models')
elif path.startswith("django.db.models.fields.proxy"):
path = path.replace("django.db.models.fields.proxy", "django.db.models")
elif path.startswith("django.db.models.fields"):
path = path.replace("django.db.models.fields", "django.db.models")
# Return basic info - other fields should override this.
return (self.name, path, [], keywords)
def clone(self):
"""
Uses deconstruct() to clone a new copy of this Field.
Will not preserve any class attachments/attribute names.
"""
name, path, args, kwargs = self.deconstruct()
return self.__class__(*args, **kwargs)
def __eq__(self, other):
# Needed for @total_ordering
if isinstance(other, Field):
return (
self.creation_counter == other.creation_counter and
getattr(self, 'model', None) == getattr(other, 'model', None)
)
return NotImplemented
def __lt__(self, other):
# This is needed because bisect does not take a comparison function.
# Order by creation_counter first for backward compatibility.
if isinstance(other, Field):
if (
self.creation_counter != other.creation_counter or
not hasattr(self, 'model') and not hasattr(other, 'model')
):
return self.creation_counter < other.creation_counter
elif hasattr(self, 'model') != hasattr(other, 'model'):
return not hasattr(self, 'model') # Order no-model fields first
else:
# creation_counter's are equal, compare only models.
return (
(self.model._meta.app_label, self.model._meta.model_name) <
(other.model._meta.app_label, other.model._meta.model_name)
)
return NotImplemented
def __hash__(self):
return hash(self.creation_counter)
def __deepcopy__(self, memodict):
# We don't have to deepcopy very much here, since most things are not
# intended to be altered after initial creation.
obj = copy.copy(self)
if self.remote_field:
obj.remote_field = copy.copy(self.remote_field)
if hasattr(self.remote_field, 'field') and self.remote_field.field is self:
obj.remote_field.field = obj
memodict[id(self)] = obj
return obj
def __copy__(self):
# We need to avoid hitting __reduce__, so define this
# slightly weird copy construct.
obj = Empty()
obj.__class__ = self.__class__
obj.__dict__ = self.__dict__.copy()
return obj
def __reduce__(self):
"""
Pickling should return the model._meta.fields instance of the field,
not a new copy of that field. So, use the app registry to load the
model and then the field back.
"""
if not hasattr(self, 'model'):
# Fields are sometimes used without attaching them to models (for
# example in aggregation). In this case give back a plain field
# instance. The code below will create a new empty instance of
# class self.__class__, then update its dict with self.__dict__
# values - so, this is very close to normal pickle.
state = self.__dict__.copy()
# The _get_default cached_property can't be pickled due to lambda
# usage.
state.pop('_get_default', None)
return _empty, (self.__class__,), state
return _load_field, (self.model._meta.app_label, self.model._meta.object_name,
self.name)
def get_pk_value_on_save(self, instance):
"""
Hook to generate new PK values on save. This method is called when
saving instances with no primary key value set. If this method returns
something else than None, then the returned value is used when saving
the new instance.
"""
if self.default:
return self.get_default()
return None
def to_python(self, value):
"""
Convert the input value into the expected Python data type, raising
django.core.exceptions.ValidationError if the data can't be converted.
Return the converted value. Subclasses should override this.
"""
return value
@cached_property
def validators(self):
"""
Some validators can't be created at field initialization time.
This method provides a way to delay their creation until required.
"""
return [*self.default_validators, *self._validators]
def run_validators(self, value):
if value in self.empty_values:
return
errors = []
for v in self.validators:
try:
v(value)
except exceptions.ValidationError as e:
if hasattr(e, 'code') and e.code in self.error_messages:
e.message = self.error_messages[e.code]
errors.extend(e.error_list)
if errors:
raise exceptions.ValidationError(errors)
def validate(self, value, model_instance):
"""
Validate value and raise ValidationError if necessary. Subclasses
should override this to provide validation logic.
"""
if not self.editable:
# Skip validation for non-editable fields.
return
if self.choices is not None and value not in self.empty_values:
for option_key, option_value in self.choices:
if isinstance(option_value, (list, tuple)):
# This is an optgroup, so look inside the group for
# options.
for optgroup_key, optgroup_value in option_value:
if value == optgroup_key:
return
elif value == option_key:
return
raise exceptions.ValidationError(
self.error_messages['invalid_choice'],
code='invalid_choice',
params={'value': value},
)
if value is None and not self.null:
raise exceptions.ValidationError(self.error_messages['null'], code='null')
if not self.blank and value in self.empty_values:
raise exceptions.ValidationError(self.error_messages['blank'], code='blank')
def clean(self, value, model_instance):
"""
Convert the value's type and run validation. Validation errors
from to_python() and validate() are propagated. Return the correct
value if no error is raised.
"""
value = self.to_python(value)
self.validate(value, model_instance)
self.run_validators(value)
return value
def db_type_parameters(self, connection):
return DictWrapper(self.__dict__, connection.ops.quote_name, 'qn_')
def db_check(self, connection):
"""
Return the database column check constraint for this field, for the
provided connection. Works the same way as db_type() for the case that
get_internal_type() does not map to a preexisting model field.
"""
data = self.db_type_parameters(connection)
try:
return connection.data_type_check_constraints[self.get_internal_type()] % data
except KeyError:
return None
def db_type(self, connection):
"""
Return the database column data type for this field, for the provided
connection.
"""
# The default implementation of this method looks at the
# backend-specific data_types dictionary, looking up the field by its
# "internal type".
#
# A Field class can implement the get_internal_type() method to specify
# which *preexisting* Django Field class it's most similar to -- i.e.,
# a custom field might be represented by a TEXT column type, which is
# the same as the TextField Django field type, which means the custom
# field's get_internal_type() returns 'TextField'.
#
# But the limitation of the get_internal_type() / data_types approach
# is that it cannot handle database column types that aren't already
# mapped to one of the built-in Django field types. In this case, you
# can implement db_type() instead of get_internal_type() to specify
# exactly which wacky database column type you want to use.
data = self.db_type_parameters(connection)
try:
return connection.data_types[self.get_internal_type()] % data
except KeyError:
return None
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. For example, this method is called by ForeignKey and OneToOneField
to determine its data type.
"""
return self.db_type(connection)
def cast_db_type(self, connection):
"""Return the data type to use in the Cast() function."""
db_type = connection.ops.cast_data_types.get(self.get_internal_type())
if db_type:
return db_type % self.db_type_parameters(connection)
return self.db_type(connection)
def db_parameters(self, connection):
"""
Extension of db_type(), providing a range of different return values
(type, checks). This will look at db_type(), allowing custom model
fields to override it.
"""
type_string = self.db_type(connection)
check_string = self.db_check(connection)
return {
"type": type_string,
"check": check_string,
}
def db_type_suffix(self, connection):
return connection.data_types_suffix.get(self.get_internal_type())
def get_db_converters(self, connection):
if hasattr(self, 'from_db_value'):
return [self.from_db_value]
return []
@property
def unique(self):
return self._unique or self.primary_key
@property
def db_tablespace(self):
return self._db_tablespace or settings.DEFAULT_INDEX_TABLESPACE
@property
def db_returning(self):
"""
Private API intended only to be used by Django itself. Currently only
the PostgreSQL backend supports returning multiple fields on a model.
"""
return False
def set_attributes_from_name(self, name):
self.name = self.name or name
self.attname, self.column = self.get_attname_column()
self.concrete = self.column is not None
if self.verbose_name is None and self.name:
self.verbose_name = self.name.replace('_', ' ')
def contribute_to_class(self, cls, name, private_only=False):
"""
Register the field with the model class it belongs to.
If private_only is True, create a separate instance of this field
for every subclass of cls, even if cls is not an abstract model.
"""
self.set_attributes_from_name(name)
self.model = cls
cls._meta.add_field(self, private=private_only)
if self.column:
setattr(cls, self.attname, self.descriptor_class(self))
if self.choices is not None:
# Don't override a get_FOO_display() method defined explicitly on
# this class, but don't check methods derived from inheritance, to
# allow overriding inherited choices. For more complex inheritance
# structures users should override contribute_to_class().
if 'get_%s_display' % self.name not in cls.__dict__:
setattr(
cls,
'get_%s_display' % self.name,
partialmethod(cls._get_FIELD_display, field=self),
)
def get_filter_kwargs_for_object(self, obj):
"""
Return a dict that when passed as kwargs to self.model.filter(), would
yield all instances having the same value for this field as obj has.
"""
return {self.name: getattr(obj, self.attname)}
def get_attname(self):
return self.name
def get_attname_column(self):
attname = self.get_attname()
column = self.db_column or attname
return attname, column
def get_internal_type(self):
return self.__class__.__name__
def pre_save(self, model_instance, add):
"""Return field's value just before saving."""
return getattr(model_instance, self.attname)
def get_prep_value(self, value):
"""Perform preliminary non-db specific value checks and conversions."""
if isinstance(value, Promise):
value = value._proxy____cast()
return value
def get_db_prep_value(self, value, connection, prepared=False):
"""
Return field's value prepared for interacting with the database backend.
Used by the default implementations of get_db_prep_save().
"""
if not prepared:
value = self.get_prep_value(value)
return value
def get_db_prep_save(self, value, connection):
"""Return field's value prepared for saving into a database."""
return self.get_db_prep_value(value, connection=connection, prepared=False)
def has_default(self):
"""Return a boolean of whether this field has a default value."""
return self.default is not NOT_PROVIDED
def get_default(self):
"""Return the default value for this field."""
return self._get_default()
@cached_property
def _get_default(self):
if self.has_default():
if callable(self.default):
return self.default
return lambda: self.default
if not self.empty_strings_allowed or self.null and not connection.features.interprets_empty_strings_as_nulls:
return return_None
return str # return empty string
def get_choices(self, include_blank=True, blank_choice=BLANK_CHOICE_DASH, limit_choices_to=None, ordering=()):
"""
Return choices with a default blank choices included, for use
as <select> choices for this field.
"""
if self.choices is not None:
choices = list(self.choices)
if include_blank:
blank_defined = any(choice in ('', None) for choice, _ in self.flatchoices)
if not blank_defined:
choices = blank_choice + choices
return choices
rel_model = self.remote_field.model
limit_choices_to = limit_choices_to or self.get_limit_choices_to()
choice_func = operator.attrgetter(
self.remote_field.get_related_field().attname
if hasattr(self.remote_field, 'get_related_field')
else 'pk'
)
qs = rel_model._default_manager.complex_filter(limit_choices_to)
if ordering:
qs = qs.order_by(*ordering)
return (blank_choice if include_blank else []) + [
(choice_func(x), str(x)) for x in qs
]
def value_to_string(self, obj):
"""
Return a string value of this field from the passed obj.
This is used by the serialization framework.
"""
return str(self.value_from_object(obj))
def _get_flatchoices(self):
"""Flattened version of choices tuple."""
if self.choices is None:
return []
flat = []
for choice, value in self.choices:
if isinstance(value, (list, tuple)):
flat.extend(value)
else:
flat.append((choice, value))
return flat
flatchoices = property(_get_flatchoices)
def save_form_data(self, instance, data):
setattr(instance, self.name, data)
def formfield(self, form_class=None, choices_form_class=None, **kwargs):
"""Return a django.forms.Field instance for this field."""
defaults = {
'required': not self.blank,
'label': capfirst(self.verbose_name),
'help_text': self.help_text,
}
if self.has_default():
if callable(self.default):
defaults['initial'] = self.default
defaults['show_hidden_initial'] = True
else:
defaults['initial'] = self.get_default()
if self.choices is not None:
# Fields with choices get special treatment.
include_blank = (self.blank or
not (self.has_default() or 'initial' in kwargs))
defaults['choices'] = self.get_choices(include_blank=include_blank)
defaults['coerce'] = self.to_python
if self.null:
defaults['empty_value'] = None
if choices_form_class is not None:
form_class = choices_form_class
else:
form_class = forms.TypedChoiceField
# Many of the subclass-specific formfield arguments (min_value,
# max_value) don't apply for choice fields, so be sure to only pass
# the values that TypedChoiceField will understand.
for k in list(kwargs):
if k not in ('coerce', 'empty_value', 'choices', 'required',
'widget', 'label', 'initial', 'help_text',
'error_messages', 'show_hidden_initial', 'disabled'):
del kwargs[k]
defaults.update(kwargs)
if form_class is None:
form_class = forms.CharField
return form_class(**defaults)
def value_from_object(self, obj):
"""Return the value of this field in the given model instance."""
return getattr(obj, self.attname)
class BooleanField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value must be either True or False.'),
'invalid_nullable': _('“%(value)s” value must be either True, False, or None.'),
}
description = _("Boolean (Either True or False)")
def get_internal_type(self):
return "BooleanField"
def to_python(self, value):
if self.null and value in self.empty_values:
return None
if value in (True, False):
# 1/0 are equal to True/False. bool() converts former to latter.
return bool(value)
if value in ('t', 'True', '1'):
return True
if value in ('f', 'False', '0'):
return False
raise exceptions.ValidationError(
self.error_messages['invalid_nullable' if self.null else 'invalid'],
code='invalid',
params={'value': value},
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return self.to_python(value)
def formfield(self, **kwargs):
if self.choices is not None:
include_blank = not (self.has_default() or 'initial' in kwargs)
defaults = {'choices': self.get_choices(include_blank=include_blank)}
else:
form_class = forms.NullBooleanField if self.null else forms.BooleanField
# In HTML checkboxes, 'required' means "must be checked" which is
# different from the choices case ("must select some value").
# required=False allows unchecked checkboxes.
defaults = {'form_class': form_class, 'required': False}
return super().formfield(**{**defaults, **kwargs})
def select_format(self, compiler, sql, params):
sql, params = super().select_format(compiler, sql, params)
# Filters that match everything are handled as empty strings in the
# WHERE clause, but in SELECT or GROUP BY list they must use a
# predicate that's always True.
if sql == '':
sql = '1'
return sql, params
class CharField(Field):
description = _("String (up to %(max_length)s)")
def __init__(self, *args, db_collation=None, **kwargs):
super().__init__(*args, **kwargs)
self.db_collation = db_collation
if self.max_length is not None:
self.validators.append(validators.MaxLengthValidator(self.max_length))
def check(self, **kwargs):
databases = kwargs.get('databases') or []
return [
*super().check(**kwargs),
*self._check_db_collation(databases),
*self._check_max_length_attribute(**kwargs),
]
def _check_max_length_attribute(self, **kwargs):
if self.max_length is None:
return [
checks.Error(
"CharFields must define a 'max_length' attribute.",
obj=self,
id='fields.E120',
)
]
elif (not isinstance(self.max_length, int) or isinstance(self.max_length, bool) or
self.max_length <= 0):
return [
checks.Error(
"'max_length' must be a positive integer.",
obj=self,
id='fields.E121',
)
]
else:
return []
def _check_db_collation(self, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
self.db_collation is None or
'supports_collation_on_charfield' in self.model._meta.required_db_features or
connection.features.supports_collation_on_charfield
):
errors.append(
checks.Error(
'%s does not support a database collation on '
'CharFields.' % connection.display_name,
obj=self,
id='fields.E190',
),
)
return errors
def cast_db_type(self, connection):
if self.max_length is None:
return connection.ops.cast_char_field_without_max_length
return super().cast_db_type(connection)
def get_internal_type(self):
return "CharField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
defaults = {'max_length': self.max_length}
# TODO: Handle multiple backends with different feature flags.
if self.null and not connection.features.interprets_empty_strings_as_nulls:
defaults['empty_value'] = None
defaults.update(kwargs)
return super().formfield(**defaults)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.db_collation:
kwargs['db_collation'] = self.db_collation
return name, path, args, kwargs
class CommaSeparatedIntegerField(CharField):
default_validators = [validators.validate_comma_separated_integer_list]
description = _("Comma-separated integers")
system_check_removed_details = {
'msg': (
'CommaSeparatedIntegerField is removed except for support in '
'historical migrations.'
),
'hint': (
'Use CharField(validators=[validate_comma_separated_integer_list]) '
'instead.'
),
'id': 'fields.E901',
}
def _to_naive(value):
if timezone.is_aware(value):
value = timezone.make_naive(value, timezone.utc)
return value
def _get_naive_now():
return _to_naive(timezone.now())
class DateTimeCheckMixin:
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_mutually_exclusive_options(),
*self._check_fix_default_value(),
]
def _check_mutually_exclusive_options(self):
# auto_now, auto_now_add, and default are mutually exclusive
# options. The use of more than one of these options together
# will trigger an Error
mutually_exclusive_options = [self.auto_now_add, self.auto_now, self.has_default()]
enabled_options = [option not in (None, False) for option in mutually_exclusive_options].count(True)
if enabled_options > 1:
return [
checks.Error(
"The options auto_now, auto_now_add, and default "
"are mutually exclusive. Only one of these options "
"may be present.",
obj=self,
id='fields.E160',
)
]
else:
return []
def _check_fix_default_value(self):
return []
# Concrete subclasses use this in their implementations of
# _check_fix_default_value().
def _check_if_value_fixed(self, value, now=None):
"""
Check if the given value appears to have been provided as a "fixed"
time value, and include a warning in the returned list if it does. The
value argument must be a date object or aware/naive datetime object. If
now is provided, it must be a naive datetime object.
"""
if now is None:
now = _get_naive_now()
offset = datetime.timedelta(seconds=10)
lower = now - offset
upper = now + offset
if isinstance(value, datetime.datetime):
value = _to_naive(value)
else:
assert isinstance(value, datetime.date)
lower = lower.date()
upper = upper.date()
if lower <= value <= upper:
return [
checks.Warning(
'Fixed default value provided.',
hint=(
'It seems you set a fixed date / time / datetime '
'value as default for this field. This may not be '
'what you want. If you want to have the current date '
'as default, use `django.utils.timezone.now`'
),
obj=self,
id='fields.W161',
)
]
return []
class DateField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value has an invalid date format. It must be '
'in YYYY-MM-DD format.'),
'invalid_date': _('“%(value)s” value has the correct format (YYYY-MM-DD) '
'but it is an invalid date.'),
}
description = _("Date (without time)")
def __init__(self, verbose_name=None, name=None, auto_now=False,
auto_now_add=False, **kwargs):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs['editable'] = False
kwargs['blank'] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, datetime.datetime):
value = _to_naive(value).date()
elif isinstance(value, datetime.date):
pass
else:
# No explicit date / datetime value -- no checks necessary
return []
# At this point, value is a date object.
return self._check_if_value_fixed(value)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now:
kwargs['auto_now'] = True
if self.auto_now_add:
kwargs['auto_now_add'] = True
if self.auto_now or self.auto_now_add:
del kwargs['editable']
del kwargs['blank']
return name, path, args, kwargs
def get_internal_type(self):
return "DateField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
if settings.USE_TZ and timezone.is_aware(value):
# Convert aware datetimes to the default time zone
# before casting them to dates (#17742).
default_timezone = timezone.get_default_timezone()
value = timezone.make_naive(value, default_timezone)
return value.date()
if isinstance(value, datetime.date):
return value
try:
parsed = parse_date(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_date'],
code='invalid_date',
params={'value': value},
)
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.date.today()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
if not self.null:
setattr(
cls, 'get_next_by_%s' % self.name,
partialmethod(cls._get_next_or_previous_by_FIELD, field=self, is_next=True)
)
setattr(
cls, 'get_previous_by_%s' % self.name,
partialmethod(cls._get_next_or_previous_by_FIELD, field=self, is_next=False)
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts dates into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.DateField,
**kwargs,
})
class DateTimeField(DateField):
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value has an invalid format. It must be in '
'YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format.'),
'invalid_date': _("“%(value)s” value has the correct format "
"(YYYY-MM-DD) but it is an invalid date."),
'invalid_datetime': _('“%(value)s” value has the correct format '
'(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) '
'but it is an invalid date/time.'),
}
description = _("Date (with time)")
# __init__ is inherited from DateField
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, (datetime.datetime, datetime.date)):
return self._check_if_value_fixed(value)
# No explicit date / datetime value -- no checks necessary.
return []
def get_internal_type(self):
return "DateTimeField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
return value
if isinstance(value, datetime.date):
value = datetime.datetime(value.year, value.month, value.day)
if settings.USE_TZ:
# For backwards compatibility, interpret naive datetimes in
# local time. This won't work during DST change, but we can't
# do much about it, so we let the exceptions percolate up the
# call stack.
warnings.warn("DateTimeField %s.%s received a naive datetime "
"(%s) while time zone support is active." %
(self.model.__name__, self.name, value),
RuntimeWarning)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
try:
parsed = parse_datetime(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_datetime'],
code='invalid_datetime',
params={'value': value},
)
try:
parsed = parse_date(value)
if parsed is not None:
return datetime.datetime(parsed.year, parsed.month, parsed.day)
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_date'],
code='invalid_date',
params={'value': value},
)
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = timezone.now()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
# contribute_to_class is inherited from DateField, it registers
# get_next_by_FOO and get_prev_by_FOO
def get_prep_value(self, value):
value = super().get_prep_value(value)
value = self.to_python(value)
if value is not None and settings.USE_TZ and timezone.is_naive(value):
# For backwards compatibility, interpret naive datetimes in local
# time. This won't work during DST change, but we can't do much
# about it, so we let the exceptions percolate up the call stack.
try:
name = '%s.%s' % (self.model.__name__, self.name)
except AttributeError:
name = '(unbound)'
warnings.warn("DateTimeField %s received a naive datetime (%s)"
" while time zone support is active." %
(name, value),
RuntimeWarning)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
def get_db_prep_value(self, value, connection, prepared=False):
# Casts datetimes into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datetimefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.DateTimeField,
**kwargs,
})
class DecimalField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value must be a decimal number.'),
}
description = _("Decimal number")
def __init__(self, verbose_name=None, name=None, max_digits=None,
decimal_places=None, **kwargs):
self.max_digits, self.decimal_places = max_digits, decimal_places
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
errors = super().check(**kwargs)
digits_errors = [
*self._check_decimal_places(),
*self._check_max_digits(),
]
if not digits_errors:
errors.extend(self._check_decimal_places_and_max_digits(**kwargs))
else:
errors.extend(digits_errors)
return errors
def _check_decimal_places(self):
try:
decimal_places = int(self.decimal_places)
if decimal_places < 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'decimal_places' attribute.",
obj=self,
id='fields.E130',
)
]
except ValueError:
return [
checks.Error(
"'decimal_places' must be a non-negative integer.",
obj=self,
id='fields.E131',
)
]
else:
return []
def _check_max_digits(self):
try:
max_digits = int(self.max_digits)
if max_digits <= 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'max_digits' attribute.",
obj=self,
id='fields.E132',
)
]
except ValueError:
return [
checks.Error(
"'max_digits' must be a positive integer.",
obj=self,
id='fields.E133',
)
]
else:
return []
def _check_decimal_places_and_max_digits(self, **kwargs):
if int(self.decimal_places) > int(self.max_digits):
return [
checks.Error(
"'max_digits' must be greater or equal to 'decimal_places'.",
obj=self,
id='fields.E134',
)
]
return []
@cached_property
def validators(self):
return super().validators + [
validators.DecimalValidator(self.max_digits, self.decimal_places)
]
@cached_property
def context(self):
return decimal.Context(prec=self.max_digits)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.max_digits is not None:
kwargs['max_digits'] = self.max_digits
if self.decimal_places is not None:
kwargs['decimal_places'] = self.decimal_places
return name, path, args, kwargs
def get_internal_type(self):
return "DecimalField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, float):
if math.isnan(value):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
return self.context.create_decimal_from_float(value)
try:
return decimal.Decimal(value)
except (decimal.InvalidOperation, TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def get_db_prep_save(self, value, connection):
return connection.ops.adapt_decimalfield_value(self.to_python(value), self.max_digits, self.decimal_places)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
return super().formfield(**{
'max_digits': self.max_digits,
'decimal_places': self.decimal_places,
'form_class': forms.DecimalField,
**kwargs,
})
class DurationField(Field):
"""
Store timedelta objects.
Use interval on PostgreSQL, INTERVAL DAY TO SECOND on Oracle, and bigint
of microseconds on other databases.
"""
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value has an invalid format. It must be in '
'[DD] [[HH:]MM:]ss[.uuuuuu] format.')
}
description = _("Duration")
def get_internal_type(self):
return "DurationField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.timedelta):
return value
try:
parsed = parse_duration(value)
except ValueError:
pass
else:
if parsed is not None:
return parsed
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def get_db_prep_value(self, value, connection, prepared=False):
if connection.features.has_native_duration_field:
return value
if value is None:
return None
return duration_microseconds(value)
def get_db_converters(self, connection):
converters = []
if not connection.features.has_native_duration_field:
converters.append(connection.ops.convert_durationfield_value)
return converters + super().get_db_converters(connection)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else duration_string(val)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.DurationField,
**kwargs,
})
class EmailField(CharField):
default_validators = [validators.validate_email]
description = _("Email address")
def __init__(self, *args, **kwargs):
# max_length=254 to be compliant with RFCs 3696 and 5321
kwargs.setdefault('max_length', 254)
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
# We do not exclude max_length if it matches default as we want to change
# the default in future.
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause email validation to be performed
# twice.
return super().formfield(**{
'form_class': forms.EmailField,
**kwargs,
})
class FilePathField(Field):
description = _("File path")
def __init__(self, verbose_name=None, name=None, path='', match=None,
recursive=False, allow_files=True, allow_folders=False, **kwargs):
self.path, self.match, self.recursive = path, match, recursive
self.allow_files, self.allow_folders = allow_files, allow_folders
kwargs.setdefault('max_length', 100)
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_allowing_files_or_folders(**kwargs),
]
def _check_allowing_files_or_folders(self, **kwargs):
if not self.allow_files and not self.allow_folders:
return [
checks.Error(
"FilePathFields must have either 'allow_files' or 'allow_folders' set to True.",
obj=self,
id='fields.E140',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.path != '':
kwargs['path'] = self.path
if self.match is not None:
kwargs['match'] = self.match
if self.recursive is not False:
kwargs['recursive'] = self.recursive
if self.allow_files is not True:
kwargs['allow_files'] = self.allow_files
if self.allow_folders is not False:
kwargs['allow_folders'] = self.allow_folders
if kwargs.get("max_length") == 100:
del kwargs["max_length"]
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def formfield(self, **kwargs):
return super().formfield(**{
'path': self.path() if callable(self.path) else self.path,
'match': self.match,
'recursive': self.recursive,
'form_class': forms.FilePathField,
'allow_files': self.allow_files,
'allow_folders': self.allow_folders,
**kwargs,
})
def get_internal_type(self):
return "FilePathField"
class FloatField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value must be a float.'),
}
description = _("Floating point number")
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
try:
return float(value)
except (TypeError, ValueError) as e:
raise e.__class__(
"Field '%s' expected a number but got %r." % (self.name, value),
) from e
def get_internal_type(self):
return "FloatField"
def to_python(self, value):
if value is None:
return value
try:
return float(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.FloatField,
**kwargs,
})
class IntegerField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value must be an integer.'),
}
description = _("Integer")
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_max_length_warning(),
]
def _check_max_length_warning(self):
if self.max_length is not None:
return [
checks.Warning(
"'max_length' is ignored when used with %s." % self.__class__.__name__,
hint="Remove 'max_length' from field",
obj=self,
id='fields.W122',
)
]
return []
@cached_property
def validators(self):
# These validators can't be added at field initialization time since
# they're based on values retrieved from `connection`.
validators_ = super().validators
internal_type = self.get_internal_type()
min_value, max_value = connection.ops.integer_field_range(internal_type)
if min_value is not None and not any(
(
isinstance(validator, validators.MinValueValidator) and (
validator.limit_value()
if callable(validator.limit_value)
else validator.limit_value
) >= min_value
) for validator in validators_
):
validators_.append(validators.MinValueValidator(min_value))
if max_value is not None and not any(
(
isinstance(validator, validators.MaxValueValidator) and (
validator.limit_value()
if callable(validator.limit_value)
else validator.limit_value
) <= max_value
) for validator in validators_
):
validators_.append(validators.MaxValueValidator(max_value))
return validators_
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
try:
return int(value)
except (TypeError, ValueError) as e:
raise e.__class__(
"Field '%s' expected a number but got %r." % (self.name, value),
) from e
def get_internal_type(self):
return "IntegerField"
def to_python(self, value):
if value is None:
return value
try:
return int(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.IntegerField,
**kwargs,
})
class BigIntegerField(IntegerField):
description = _("Big (8 byte) integer")
MAX_BIGINT = 9223372036854775807
def get_internal_type(self):
return "BigIntegerField"
def formfield(self, **kwargs):
return super().formfield(**{
'min_value': -BigIntegerField.MAX_BIGINT - 1,
'max_value': BigIntegerField.MAX_BIGINT,
**kwargs,
})
class SmallIntegerField(IntegerField):
description = _('Small integer')
def get_internal_type(self):
return 'SmallIntegerField'
class IPAddressField(Field):
empty_strings_allowed = False
description = _("IPv4 address")
system_check_removed_details = {
'msg': (
'IPAddressField has been removed except for support in '
'historical migrations.'
),
'hint': 'Use GenericIPAddressField instead.',
'id': 'fields.E900',
}
def __init__(self, *args, **kwargs):
kwargs['max_length'] = 15
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['max_length']
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def get_internal_type(self):
return "IPAddressField"
class GenericIPAddressField(Field):
empty_strings_allowed = False
description = _("IP address")
default_error_messages = {}
def __init__(self, verbose_name=None, name=None, protocol='both',
unpack_ipv4=False, *args, **kwargs):
self.unpack_ipv4 = unpack_ipv4
self.protocol = protocol
self.default_validators, invalid_error_message = \
validators.ip_address_validators(protocol, unpack_ipv4)
self.default_error_messages['invalid'] = invalid_error_message
kwargs['max_length'] = 39
super().__init__(verbose_name, name, *args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_blank_and_null_values(**kwargs),
]
def _check_blank_and_null_values(self, **kwargs):
if not getattr(self, 'null', False) and getattr(self, 'blank', False):
return [
checks.Error(
'GenericIPAddressFields cannot have blank=True if null=False, '
'as blank values are stored as nulls.',
obj=self,
id='fields.E150',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.unpack_ipv4 is not False:
kwargs['unpack_ipv4'] = self.unpack_ipv4
if self.protocol != "both":
kwargs['protocol'] = self.protocol
if kwargs.get("max_length") == 39:
del kwargs['max_length']
return name, path, args, kwargs
def get_internal_type(self):
return "GenericIPAddressField"
def to_python(self, value):
if value is None:
return None
if not isinstance(value, str):
value = str(value)
value = value.strip()
if ':' in value:
return clean_ipv6_address(value, self.unpack_ipv4, self.error_messages['invalid'])
return value
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_ipaddressfield_value(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
if value and ':' in value:
try:
return clean_ipv6_address(value, self.unpack_ipv4)
except exceptions.ValidationError:
pass
return str(value)
def formfield(self, **kwargs):
return super().formfield(**{
'protocol': self.protocol,
'form_class': forms.GenericIPAddressField,
**kwargs,
})
class NullBooleanField(BooleanField):
default_error_messages = {
'invalid': _('“%(value)s” value must be either None, True or False.'),
'invalid_nullable': _('“%(value)s” value must be either None, True or False.'),
}
description = _("Boolean (Either True, False or None)")
system_check_removed_details = {
'msg': (
'NullBooleanField is removed except for support in historical '
'migrations.'
),
'hint': 'Use BooleanField(null=True) instead.',
'id': 'fields.E903',
}
def __init__(self, *args, **kwargs):
kwargs['null'] = True
kwargs['blank'] = True
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['null']
del kwargs['blank']
return name, path, args, kwargs
class PositiveIntegerRelDbTypeMixin:
def __init_subclass__(cls, **kwargs):
super().__init_subclass__(**kwargs)
if not hasattr(cls, 'integer_field_class'):
cls.integer_field_class = next(
(
parent
for parent in cls.__mro__[1:]
if issubclass(parent, IntegerField)
),
None,
)
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. In most cases, a foreign key pointing to a positive integer
primary key will have an integer column data type but some databases
(e.g. MySQL) have an unsigned integer type. In that case
(related_fields_match_type=True), the primary key should return its
db_type.
"""
if connection.features.related_fields_match_type:
return self.db_type(connection)
else:
return self.integer_field_class().db_type(connection=connection)
class PositiveBigIntegerField(PositiveIntegerRelDbTypeMixin, BigIntegerField):
description = _('Positive big integer')
def get_internal_type(self):
return 'PositiveBigIntegerField'
def formfield(self, **kwargs):
return super().formfield(**{
'min_value': 0,
**kwargs,
})
class PositiveIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField):
description = _("Positive integer")
def get_internal_type(self):
return "PositiveIntegerField"
def formfield(self, **kwargs):
return super().formfield(**{
'min_value': 0,
**kwargs,
})
class PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin, SmallIntegerField):
description = _("Positive small integer")
def get_internal_type(self):
return "PositiveSmallIntegerField"
def formfield(self, **kwargs):
return super().formfield(**{
'min_value': 0,
**kwargs,
})
class SlugField(CharField):
default_validators = [validators.validate_slug]
description = _("Slug (up to %(max_length)s)")
def __init__(self, *args, max_length=50, db_index=True, allow_unicode=False, **kwargs):
self.allow_unicode = allow_unicode
if self.allow_unicode:
self.default_validators = [validators.validate_unicode_slug]
super().__init__(*args, max_length=max_length, db_index=db_index, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 50:
del kwargs['max_length']
if self.db_index is False:
kwargs['db_index'] = False
else:
del kwargs['db_index']
if self.allow_unicode is not False:
kwargs['allow_unicode'] = self.allow_unicode
return name, path, args, kwargs
def get_internal_type(self):
return "SlugField"
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.SlugField,
'allow_unicode': self.allow_unicode,
**kwargs,
})
class TextField(Field):
description = _("Text")
def __init__(self, *args, db_collation=None, **kwargs):
super().__init__(*args, **kwargs)
self.db_collation = db_collation
def check(self, **kwargs):
databases = kwargs.get('databases') or []
return [
*super().check(**kwargs),
*self._check_db_collation(databases),
]
def _check_db_collation(self, databases):
errors = []
for db in databases:
if not router.allow_migrate_model(db, self.model):
continue
connection = connections[db]
if not (
self.db_collation is None or
'supports_collation_on_textfield' in self.model._meta.required_db_features or
connection.features.supports_collation_on_textfield
):
errors.append(
checks.Error(
'%s does not support a database collation on '
'TextFields.' % connection.display_name,
obj=self,
id='fields.E190',
),
)
return errors
def get_internal_type(self):
return "TextField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
return super().formfield(**{
'max_length': self.max_length,
**({} if self.choices is not None else {'widget': forms.Textarea}),
**kwargs,
})
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.db_collation:
kwargs['db_collation'] = self.db_collation
return name, path, args, kwargs
class TimeField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _('“%(value)s” value has an invalid format. It must be in '
'HH:MM[:ss[.uuuuuu]] format.'),
'invalid_time': _('“%(value)s” value has the correct format '
'(HH:MM[:ss[.uuuuuu]]) but it is an invalid time.'),
}
description = _("Time")
def __init__(self, verbose_name=None, name=None, auto_now=False,
auto_now_add=False, **kwargs):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs['editable'] = False
kwargs['blank'] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
value = self.default
if isinstance(value, datetime.datetime):
now = None
elif isinstance(value, datetime.time):
now = _get_naive_now()
# This will not use the right date in the race condition where now
# is just before the date change and value is just past 0:00.
value = datetime.datetime.combine(now.date(), value)
else:
# No explicit time / datetime value -- no checks necessary
return []
# At this point, value is a datetime object.
return self._check_if_value_fixed(value, now=now)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now is not False:
kwargs["auto_now"] = self.auto_now
if self.auto_now_add is not False:
kwargs["auto_now_add"] = self.auto_now_add
if self.auto_now or self.auto_now_add:
del kwargs['blank']
del kwargs['editable']
return name, path, args, kwargs
def get_internal_type(self):
return "TimeField"
def to_python(self, value):
if value is None:
return None
if isinstance(value, datetime.time):
return value
if isinstance(value, datetime.datetime):
# Not usually a good idea to pass in a datetime here (it loses
# information), but this can be a side-effect of interacting with a
# database backend (e.g. Oracle), so we'll be accommodating.
return value.time()
try:
parsed = parse_time(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_time'],
code='invalid_time',
params={'value': value},
)
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.datetime.now().time()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts times into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_timefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.TimeField,
**kwargs,
})
class URLField(CharField):
default_validators = [validators.URLValidator()]
description = _("URL")
def __init__(self, verbose_name=None, name=None, **kwargs):
kwargs.setdefault('max_length', 200)
super().__init__(verbose_name, name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 200:
del kwargs['max_length']
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause URL validation to be performed
# twice.
return super().formfield(**{
'form_class': forms.URLField,
**kwargs,
})
class BinaryField(Field):
description = _("Raw binary data")
empty_values = [None, b'']
def __init__(self, *args, **kwargs):
kwargs.setdefault('editable', False)
super().__init__(*args, **kwargs)
if self.max_length is not None:
self.validators.append(validators.MaxLengthValidator(self.max_length))
def check(self, **kwargs):
return [*super().check(**kwargs), *self._check_str_default_value()]
def _check_str_default_value(self):
if self.has_default() and isinstance(self.default, str):
return [
checks.Error(
"BinaryField's default cannot be a string. Use bytes "
"content instead.",
obj=self,
id='fields.E170',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.editable:
kwargs['editable'] = True
else:
del kwargs['editable']
return name, path, args, kwargs
def get_internal_type(self):
return "BinaryField"
def get_placeholder(self, value, compiler, connection):
return connection.ops.binary_placeholder_sql(value)
def get_default(self):
if self.has_default() and not callable(self.default):
return self.default
default = super().get_default()
if default == '':
return b''
return default
def get_db_prep_value(self, value, connection, prepared=False):
value = super().get_db_prep_value(value, connection, prepared)
if value is not None:
return connection.Database.Binary(value)
return value
def value_to_string(self, obj):
"""Binary data is serialized as base64"""
return b64encode(self.value_from_object(obj)).decode('ascii')
def to_python(self, value):
# If it's a string, it should be base64-encoded data
if isinstance(value, str):
return memoryview(b64decode(value.encode('ascii')))
return value
class UUIDField(Field):
default_error_messages = {
'invalid': _('“%(value)s” is not a valid UUID.'),
}
description = _('Universally unique identifier')
empty_strings_allowed = False
def __init__(self, verbose_name=None, **kwargs):
kwargs['max_length'] = 32
super().__init__(verbose_name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['max_length']
return name, path, args, kwargs
def get_internal_type(self):
return "UUIDField"
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
if value is None:
return None
if not isinstance(value, uuid.UUID):
value = self.to_python(value)
if connection.features.has_native_uuid_field:
return value
return value.hex
def to_python(self, value):
if value is not None and not isinstance(value, uuid.UUID):
input_form = 'int' if isinstance(value, int) else 'hex'
try:
return uuid.UUID(**{input_form: value})
except (AttributeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
return value
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.UUIDField,
**kwargs,
})
class AutoFieldMixin:
db_returning = True
def __init__(self, *args, **kwargs):
kwargs['blank'] = True
super().__init__(*args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_primary_key(),
]
def _check_primary_key(self):
if not self.primary_key:
return [
checks.Error(
'AutoFields must set primary_key=True.',
obj=self,
id='fields.E100',
),
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['blank']
kwargs['primary_key'] = True
return name, path, args, kwargs
def validate(self, value, model_instance):
pass
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
value = connection.ops.validate_autopk_value(value)
return value
def contribute_to_class(self, cls, name, **kwargs):
if cls._meta.auto_field:
raise ValueError(
"Model %s can't have more than one auto-generated field."
% cls._meta.label
)
super().contribute_to_class(cls, name, **kwargs)
cls._meta.auto_field = self
def formfield(self, **kwargs):
return None
class AutoFieldMeta(type):
"""
Metaclass to maintain backward inheritance compatibility for AutoField.
It is intended that AutoFieldMixin become public API when it is possible to
create a non-integer automatically-generated field using column defaults
stored in the database.
In many areas Django also relies on using isinstance() to check for an
automatically-generated field as a subclass of AutoField. A new flag needs
to be implemented on Field to be used instead.
When these issues have been addressed, this metaclass could be used to
deprecate inheritance from AutoField and use of isinstance() with AutoField
for detecting automatically-generated fields.
"""
@property
def _subclasses(self):
return (BigAutoField, SmallAutoField)
def __instancecheck__(self, instance):
return isinstance(instance, self._subclasses) or super().__instancecheck__(instance)
def __subclasscheck__(self, subclass):
return issubclass(subclass, self._subclasses) or super().__subclasscheck__(subclass)
class AutoField(AutoFieldMixin, IntegerField, metaclass=AutoFieldMeta):
def get_internal_type(self):
return 'AutoField'
def rel_db_type(self, connection):
return IntegerField().db_type(connection=connection)
class BigAutoField(AutoFieldMixin, BigIntegerField):
def get_internal_type(self):
return 'BigAutoField'
def rel_db_type(self, connection):
return BigIntegerField().db_type(connection=connection)
class SmallAutoField(AutoFieldMixin, SmallIntegerField):
def get_internal_type(self):
return 'SmallAutoField'
def rel_db_type(self, connection):
return SmallIntegerField().db_type(connection=connection)
|
da7113308f6eea83d75d30c4cd5e10a231e135c70eee8817e468aa93cf04e800 | import functools
import inspect
from functools import partial
from django import forms
from django.apps import apps
from django.conf import SettingsReference, settings
from django.core import checks, exceptions
from django.db import connection, router
from django.db.backends import utils
from django.db.models import Q
from django.db.models.constants import LOOKUP_SEP
from django.db.models.deletion import CASCADE, SET_DEFAULT, SET_NULL
from django.db.models.query_utils import PathInfo
from django.db.models.utils import make_model_tuple
from django.utils.functional import cached_property
from django.utils.translation import gettext_lazy as _
from . import Field
from .mixins import FieldCacheMixin
from .related_descriptors import (
ForeignKeyDeferredAttribute, ForwardManyToOneDescriptor,
ForwardOneToOneDescriptor, ManyToManyDescriptor,
ReverseManyToOneDescriptor, ReverseOneToOneDescriptor,
)
from .related_lookups import (
RelatedExact, RelatedGreaterThan, RelatedGreaterThanOrEqual, RelatedIn,
RelatedIsNull, RelatedLessThan, RelatedLessThanOrEqual,
)
from .reverse_related import (
ForeignObjectRel, ManyToManyRel, ManyToOneRel, OneToOneRel,
)
RECURSIVE_RELATIONSHIP_CONSTANT = 'self'
def resolve_relation(scope_model, relation):
"""
Transform relation into a model or fully-qualified model string of the form
"app_label.ModelName", relative to scope_model.
The relation argument can be:
* RECURSIVE_RELATIONSHIP_CONSTANT, i.e. the string "self", in which case
the model argument will be returned.
* A bare model name without an app_label, in which case scope_model's
app_label will be prepended.
* An "app_label.ModelName" string.
* A model class, which will be returned unchanged.
"""
# Check for recursive relations
if relation == RECURSIVE_RELATIONSHIP_CONSTANT:
relation = scope_model
# Look for an "app.Model" relation
if isinstance(relation, str):
if "." not in relation:
relation = "%s.%s" % (scope_model._meta.app_label, relation)
return relation
def lazy_related_operation(function, model, *related_models, **kwargs):
"""
Schedule `function` to be called once `model` and all `related_models`
have been imported and registered with the app registry. `function` will
be called with the newly-loaded model classes as its positional arguments,
plus any optional keyword arguments.
The `model` argument must be a model class. Each subsequent positional
argument is another model, or a reference to another model - see
`resolve_relation()` for the various forms these may take. Any relative
references will be resolved relative to `model`.
This is a convenience wrapper for `Apps.lazy_model_operation` - the app
registry model used is the one found in `model._meta.apps`.
"""
models = [model] + [resolve_relation(model, rel) for rel in related_models]
model_keys = (make_model_tuple(m) for m in models)
apps = model._meta.apps
return apps.lazy_model_operation(partial(function, **kwargs), *model_keys)
class RelatedField(FieldCacheMixin, Field):
"""Base class that all relational fields inherit from."""
# Field flags
one_to_many = False
one_to_one = False
many_to_many = False
many_to_one = False
def __init__(
self,
related_name=None,
related_query_name=None,
limit_choices_to=None,
**kwargs,
):
self._related_name = related_name
self._related_query_name = related_query_name
self._limit_choices_to = limit_choices_to
super().__init__(**kwargs)
@cached_property
def related_model(self):
# Can't cache this property until all the models are loaded.
apps.check_models_ready()
return self.remote_field.model
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_related_name_is_valid(),
*self._check_related_query_name_is_valid(),
*self._check_relation_model_exists(),
*self._check_referencing_to_swapped_model(),
*self._check_clashes(),
]
def _check_related_name_is_valid(self):
import keyword
related_name = self.remote_field.related_name
if related_name is None:
return []
is_valid_id = not keyword.iskeyword(related_name) and related_name.isidentifier()
if not (is_valid_id or related_name.endswith('+')):
return [
checks.Error(
"The name '%s' is invalid related_name for field %s.%s" %
(self.remote_field.related_name, self.model._meta.object_name,
self.name),
hint="Related name must be a valid Python identifier or end with a '+'",
obj=self,
id='fields.E306',
)
]
return []
def _check_related_query_name_is_valid(self):
if self.remote_field.is_hidden():
return []
rel_query_name = self.related_query_name()
errors = []
if rel_query_name.endswith('_'):
errors.append(
checks.Error(
"Reverse query name '%s' must not end with an underscore."
% rel_query_name,
hint=("Add or change a related_name or related_query_name "
"argument for this field."),
obj=self,
id='fields.E308',
)
)
if LOOKUP_SEP in rel_query_name:
errors.append(
checks.Error(
"Reverse query name '%s' must not contain '%s'."
% (rel_query_name, LOOKUP_SEP),
hint=("Add or change a related_name or related_query_name "
"argument for this field."),
obj=self,
id='fields.E309',
)
)
return errors
def _check_relation_model_exists(self):
rel_is_missing = self.remote_field.model not in self.opts.apps.get_models()
rel_is_string = isinstance(self.remote_field.model, str)
model_name = self.remote_field.model if rel_is_string else self.remote_field.model._meta.object_name
if rel_is_missing and (rel_is_string or not self.remote_field.model._meta.swapped):
return [
checks.Error(
"Field defines a relation with model '%s', which is either "
"not installed, or is abstract." % model_name,
obj=self,
id='fields.E300',
)
]
return []
def _check_referencing_to_swapped_model(self):
if (self.remote_field.model not in self.opts.apps.get_models() and
not isinstance(self.remote_field.model, str) and
self.remote_field.model._meta.swapped):
return [
checks.Error(
"Field defines a relation with the model '%s', which has "
"been swapped out." % self.remote_field.model._meta.label,
hint="Update the relation to point at 'settings.%s'." % self.remote_field.model._meta.swappable,
obj=self,
id='fields.E301',
)
]
return []
def _check_clashes(self):
"""Check accessor and reverse query name clashes."""
from django.db.models.base import ModelBase
errors = []
opts = self.model._meta
# `f.remote_field.model` may be a string instead of a model. Skip if model name is
# not resolved.
if not isinstance(self.remote_field.model, ModelBase):
return []
# Consider that we are checking field `Model.foreign` and the models
# are:
#
# class Target(models.Model):
# model = models.IntegerField()
# model_set = models.IntegerField()
#
# class Model(models.Model):
# foreign = models.ForeignKey(Target)
# m2m = models.ManyToManyField(Target)
# rel_opts.object_name == "Target"
rel_opts = self.remote_field.model._meta
# If the field doesn't install a backward relation on the target model
# (so `is_hidden` returns True), then there are no clashes to check
# and we can skip these fields.
rel_is_hidden = self.remote_field.is_hidden()
rel_name = self.remote_field.get_accessor_name() # i. e. "model_set"
rel_query_name = self.related_query_name() # i. e. "model"
# i.e. "app_label.Model.field".
field_name = '%s.%s' % (opts.label, self.name)
# Check clashes between accessor or reverse query name of `field`
# and any other field name -- i.e. accessor for Model.foreign is
# model_set and it clashes with Target.model_set.
potential_clashes = rel_opts.fields + rel_opts.many_to_many
for clash_field in potential_clashes:
# i.e. "app_label.Target.model_set".
clash_name = '%s.%s' % (rel_opts.label, clash_field.name)
if not rel_is_hidden and clash_field.name == rel_name:
errors.append(
checks.Error(
f"Reverse accessor '{rel_opts.object_name}.{rel_name}' "
f"for '{field_name}' clashes with field name "
f"'{clash_name}'.",
hint=("Rename field '%s', or add/change a related_name "
"argument to the definition for field '%s'.") % (clash_name, field_name),
obj=self,
id='fields.E302',
)
)
if clash_field.name == rel_query_name:
errors.append(
checks.Error(
"Reverse query name for '%s' clashes with field name '%s'." % (field_name, clash_name),
hint=("Rename field '%s', or add/change a related_name "
"argument to the definition for field '%s'.") % (clash_name, field_name),
obj=self,
id='fields.E303',
)
)
# Check clashes between accessors/reverse query names of `field` and
# any other field accessor -- i. e. Model.foreign accessor clashes with
# Model.m2m accessor.
potential_clashes = (r for r in rel_opts.related_objects if r.field is not self)
for clash_field in potential_clashes:
# i.e. "app_label.Model.m2m".
clash_name = '%s.%s' % (
clash_field.related_model._meta.label,
clash_field.field.name,
)
if not rel_is_hidden and clash_field.get_accessor_name() == rel_name:
errors.append(
checks.Error(
f"Reverse accessor '{rel_opts.object_name}.{rel_name}' "
f"for '{field_name}' clashes with reverse accessor for "
f"'{clash_name}'.",
hint=("Add or change a related_name argument "
"to the definition for '%s' or '%s'.") % (field_name, clash_name),
obj=self,
id='fields.E304',
)
)
if clash_field.get_accessor_name() == rel_query_name:
errors.append(
checks.Error(
"Reverse query name for '%s' clashes with reverse query name for '%s'."
% (field_name, clash_name),
hint=("Add or change a related_name argument "
"to the definition for '%s' or '%s'.") % (field_name, clash_name),
obj=self,
id='fields.E305',
)
)
return errors
def db_type(self, connection):
# By default related field will not have a column as it relates to
# columns from another table.
return None
def contribute_to_class(self, cls, name, private_only=False, **kwargs):
super().contribute_to_class(cls, name, private_only=private_only, **kwargs)
self.opts = cls._meta
if not cls._meta.abstract:
if self.remote_field.related_name:
related_name = self.remote_field.related_name
else:
related_name = self.opts.default_related_name
if related_name:
related_name = related_name % {
'class': cls.__name__.lower(),
'model_name': cls._meta.model_name.lower(),
'app_label': cls._meta.app_label.lower()
}
self.remote_field.related_name = related_name
if self.remote_field.related_query_name:
related_query_name = self.remote_field.related_query_name % {
'class': cls.__name__.lower(),
'app_label': cls._meta.app_label.lower(),
}
self.remote_field.related_query_name = related_query_name
def resolve_related_class(model, related, field):
field.remote_field.model = related
field.do_related_class(related, model)
lazy_related_operation(resolve_related_class, cls, self.remote_field.model, field=self)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self._limit_choices_to:
kwargs['limit_choices_to'] = self._limit_choices_to
if self._related_name is not None:
kwargs['related_name'] = self._related_name
if self._related_query_name is not None:
kwargs['related_query_name'] = self._related_query_name
return name, path, args, kwargs
def get_forward_related_filter(self, obj):
"""
Return the keyword arguments that when supplied to
self.model.object.filter(), would select all instances related through
this field to the remote obj. This is used to build the querysets
returned by related descriptors. obj is an instance of
self.related_field.model.
"""
return {
'%s__%s' % (self.name, rh_field.name): getattr(obj, rh_field.attname)
for _, rh_field in self.related_fields
}
def get_reverse_related_filter(self, obj):
"""
Complement to get_forward_related_filter(). Return the keyword
arguments that when passed to self.related_field.model.object.filter()
select all instances of self.related_field.model related through
this field to obj. obj is an instance of self.model.
"""
base_filter = (
(rh_field.attname, getattr(obj, lh_field.attname))
for lh_field, rh_field in self.related_fields
)
descriptor_filter = self.get_extra_descriptor_filter(obj)
base_q = Q(*base_filter)
if isinstance(descriptor_filter, dict):
return base_q & Q(**descriptor_filter)
elif descriptor_filter:
return base_q & descriptor_filter
return base_q
@property
def swappable_setting(self):
"""
Get the setting that this is powered from for swapping, or None
if it's not swapped in / marked with swappable=False.
"""
if self.swappable:
# Work out string form of "to"
if isinstance(self.remote_field.model, str):
to_string = self.remote_field.model
else:
to_string = self.remote_field.model._meta.label
return apps.get_swappable_settings_name(to_string)
return None
def set_attributes_from_rel(self):
self.name = (
self.name or
(self.remote_field.model._meta.model_name + '_' + self.remote_field.model._meta.pk.name)
)
if self.verbose_name is None:
self.verbose_name = self.remote_field.model._meta.verbose_name
self.remote_field.set_field_name()
def do_related_class(self, other, cls):
self.set_attributes_from_rel()
self.contribute_to_related_class(other, self.remote_field)
def get_limit_choices_to(self):
"""
Return ``limit_choices_to`` for this model field.
If it is a callable, it will be invoked and the result will be
returned.
"""
if callable(self.remote_field.limit_choices_to):
return self.remote_field.limit_choices_to()
return self.remote_field.limit_choices_to
def formfield(self, **kwargs):
"""
Pass ``limit_choices_to`` to the field being constructed.
Only passes it if there is a type that supports related fields.
This is a similar strategy used to pass the ``queryset`` to the field
being constructed.
"""
defaults = {}
if hasattr(self.remote_field, 'get_related_field'):
# If this is a callable, do not invoke it here. Just pass
# it in the defaults for when the form class will later be
# instantiated.
limit_choices_to = self.remote_field.limit_choices_to
defaults.update({
'limit_choices_to': limit_choices_to,
})
defaults.update(kwargs)
return super().formfield(**defaults)
def related_query_name(self):
"""
Define the name that can be used to identify this related object in a
table-spanning query.
"""
return self.remote_field.related_query_name or self.remote_field.related_name or self.opts.model_name
@property
def target_field(self):
"""
When filtering against this relation, return the field on the remote
model against which the filtering should happen.
"""
target_fields = self.path_infos[-1].target_fields
if len(target_fields) > 1:
raise exceptions.FieldError(
"The relation has multiple target fields, but only single target field was asked for")
return target_fields[0]
def get_cache_name(self):
return self.name
class ForeignObject(RelatedField):
"""
Abstraction of the ForeignKey relation to support multi-column relations.
"""
# Field flags
many_to_many = False
many_to_one = True
one_to_many = False
one_to_one = False
requires_unique_target = True
related_accessor_class = ReverseManyToOneDescriptor
forward_related_accessor_class = ForwardManyToOneDescriptor
rel_class = ForeignObjectRel
def __init__(self, to, on_delete, from_fields, to_fields, rel=None, related_name=None,
related_query_name=None, limit_choices_to=None, parent_link=False,
swappable=True, **kwargs):
if rel is None:
rel = self.rel_class(
self, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
super().__init__(
rel=rel,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
**kwargs,
)
self.from_fields = from_fields
self.to_fields = to_fields
self.swappable = swappable
def __copy__(self):
obj = super().__copy__()
# Remove any cached PathInfo values.
obj.__dict__.pop('path_infos', None)
obj.__dict__.pop('reverse_path_infos', None)
return obj
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_to_fields_exist(),
*self._check_unique_target(),
]
def _check_to_fields_exist(self):
# Skip nonexistent models.
if isinstance(self.remote_field.model, str):
return []
errors = []
for to_field in self.to_fields:
if to_field:
try:
self.remote_field.model._meta.get_field(to_field)
except exceptions.FieldDoesNotExist:
errors.append(
checks.Error(
"The to_field '%s' doesn't exist on the related "
"model '%s'."
% (to_field, self.remote_field.model._meta.label),
obj=self,
id='fields.E312',
)
)
return errors
def _check_unique_target(self):
rel_is_string = isinstance(self.remote_field.model, str)
if rel_is_string or not self.requires_unique_target:
return []
try:
self.foreign_related_fields
except exceptions.FieldDoesNotExist:
return []
if not self.foreign_related_fields:
return []
unique_foreign_fields = {
frozenset([f.name])
for f in self.remote_field.model._meta.get_fields()
if getattr(f, 'unique', False)
}
unique_foreign_fields.update({
frozenset(ut)
for ut in self.remote_field.model._meta.unique_together
})
unique_foreign_fields.update({
frozenset(uc.fields)
for uc in self.remote_field.model._meta.total_unique_constraints
})
foreign_fields = {f.name for f in self.foreign_related_fields}
has_unique_constraint = any(u <= foreign_fields for u in unique_foreign_fields)
if not has_unique_constraint and len(self.foreign_related_fields) > 1:
field_combination = ', '.join(
"'%s'" % rel_field.name for rel_field in self.foreign_related_fields
)
model_name = self.remote_field.model.__name__
return [
checks.Error(
"No subset of the fields %s on model '%s' is unique."
% (field_combination, model_name),
hint=(
'Mark a single field as unique=True or add a set of '
'fields to a unique constraint (via unique_together '
'or a UniqueConstraint (without condition) in the '
'model Meta.constraints).'
),
obj=self,
id='fields.E310',
)
]
elif not has_unique_constraint:
field_name = self.foreign_related_fields[0].name
model_name = self.remote_field.model.__name__
return [
checks.Error(
"'%s.%s' must be unique because it is referenced by "
"a foreign key." % (model_name, field_name),
hint=(
'Add unique=True to this field or add a '
'UniqueConstraint (without condition) in the model '
'Meta.constraints.'
),
obj=self,
id='fields.E311',
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
kwargs['on_delete'] = self.remote_field.on_delete
kwargs['from_fields'] = self.from_fields
kwargs['to_fields'] = self.to_fields
if self.remote_field.parent_link:
kwargs['parent_link'] = self.remote_field.parent_link
if isinstance(self.remote_field.model, str):
if '.' in self.remote_field.model:
app_label, model_name = self.remote_field.model.split('.')
kwargs['to'] = '%s.%s' % (app_label, model_name.lower())
else:
kwargs['to'] = self.remote_field.model.lower()
else:
kwargs['to'] = self.remote_field.model._meta.label_lower
# If swappable is True, then see if we're actually pointing to the target
# of a swap.
swappable_setting = self.swappable_setting
if swappable_setting is not None:
# If it's already a settings reference, error
if hasattr(kwargs['to'], "setting_name"):
if kwargs['to'].setting_name != swappable_setting:
raise ValueError(
"Cannot deconstruct a ForeignKey pointing to a model "
"that is swapped in place of more than one model (%s and %s)"
% (kwargs['to'].setting_name, swappable_setting)
)
# Set it
kwargs['to'] = SettingsReference(
kwargs['to'],
swappable_setting,
)
return name, path, args, kwargs
def resolve_related_fields(self):
if not self.from_fields or len(self.from_fields) != len(self.to_fields):
raise ValueError('Foreign Object from and to fields must be the same non-zero length')
if isinstance(self.remote_field.model, str):
raise ValueError('Related model %r cannot be resolved' % self.remote_field.model)
related_fields = []
for index in range(len(self.from_fields)):
from_field_name = self.from_fields[index]
to_field_name = self.to_fields[index]
from_field = (
self
if from_field_name == RECURSIVE_RELATIONSHIP_CONSTANT
else self.opts.get_field(from_field_name)
)
to_field = (self.remote_field.model._meta.pk if to_field_name is None
else self.remote_field.model._meta.get_field(to_field_name))
related_fields.append((from_field, to_field))
return related_fields
@cached_property
def related_fields(self):
return self.resolve_related_fields()
@cached_property
def reverse_related_fields(self):
return [(rhs_field, lhs_field) for lhs_field, rhs_field in self.related_fields]
@cached_property
def local_related_fields(self):
return tuple(lhs_field for lhs_field, rhs_field in self.related_fields)
@cached_property
def foreign_related_fields(self):
return tuple(rhs_field for lhs_field, rhs_field in self.related_fields if rhs_field)
def get_local_related_value(self, instance):
return self.get_instance_value_for_fields(instance, self.local_related_fields)
def get_foreign_related_value(self, instance):
return self.get_instance_value_for_fields(instance, self.foreign_related_fields)
@staticmethod
def get_instance_value_for_fields(instance, fields):
ret = []
opts = instance._meta
for field in fields:
# Gotcha: in some cases (like fixture loading) a model can have
# different values in parent_ptr_id and parent's id. So, use
# instance.pk (that is, parent_ptr_id) when asked for instance.id.
if field.primary_key:
possible_parent_link = opts.get_ancestor_link(field.model)
if (not possible_parent_link or
possible_parent_link.primary_key or
possible_parent_link.model._meta.abstract):
ret.append(instance.pk)
continue
ret.append(getattr(instance, field.attname))
return tuple(ret)
def get_attname_column(self):
attname, column = super().get_attname_column()
return attname, None
def get_joining_columns(self, reverse_join=False):
source = self.reverse_related_fields if reverse_join else self.related_fields
return tuple((lhs_field.column, rhs_field.column) for lhs_field, rhs_field in source)
def get_reverse_joining_columns(self):
return self.get_joining_columns(reverse_join=True)
def get_extra_descriptor_filter(self, instance):
"""
Return an extra filter condition for related object fetching when
user does 'instance.fieldname', that is the extra filter is used in
the descriptor of the field.
The filter should be either a dict usable in .filter(**kwargs) call or
a Q-object. The condition will be ANDed together with the relation's
joining columns.
A parallel method is get_extra_restriction() which is used in
JOIN and subquery conditions.
"""
return {}
def get_extra_restriction(self, alias, related_alias):
"""
Return a pair condition used for joining and subquery pushdown. The
condition is something that responds to as_sql(compiler, connection)
method.
Note that currently referring both the 'alias' and 'related_alias'
will not work in some conditions, like subquery pushdown.
A parallel method is get_extra_descriptor_filter() which is used in
instance.fieldname related object fetching.
"""
return None
def get_path_info(self, filtered_relation=None):
"""Get path from this field to the related model."""
opts = self.remote_field.model._meta
from_opts = self.model._meta
return [PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=self.foreign_related_fields,
join_field=self,
m2m=False,
direct=True,
filtered_relation=filtered_relation,
)]
@cached_property
def path_infos(self):
return self.get_path_info()
def get_reverse_path_info(self, filtered_relation=None):
"""Get path from the related model to this field's model."""
opts = self.model._meta
from_opts = self.remote_field.model._meta
return [PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=(opts.pk,),
join_field=self.remote_field,
m2m=not self.unique,
direct=False,
filtered_relation=filtered_relation,
)]
@cached_property
def reverse_path_infos(self):
return self.get_reverse_path_info()
@classmethod
@functools.lru_cache(maxsize=None)
def get_lookups(cls):
bases = inspect.getmro(cls)
bases = bases[:bases.index(ForeignObject) + 1]
class_lookups = [parent.__dict__.get('class_lookups', {}) for parent in bases]
return cls.merge_dicts(class_lookups)
def contribute_to_class(self, cls, name, private_only=False, **kwargs):
super().contribute_to_class(cls, name, private_only=private_only, **kwargs)
setattr(cls, self.name, self.forward_related_accessor_class(self))
def contribute_to_related_class(self, cls, related):
# Internal FK's - i.e., those with a related name ending with '+' -
# and swapped models don't get a related descriptor.
if not self.remote_field.is_hidden() and not related.related_model._meta.swapped:
setattr(cls._meta.concrete_model, related.get_accessor_name(), self.related_accessor_class(related))
# While 'limit_choices_to' might be a callable, simply pass
# it along for later - this is too early because it's still
# model load time.
if self.remote_field.limit_choices_to:
cls._meta.related_fkey_lookups.append(self.remote_field.limit_choices_to)
ForeignObject.register_lookup(RelatedIn)
ForeignObject.register_lookup(RelatedExact)
ForeignObject.register_lookup(RelatedLessThan)
ForeignObject.register_lookup(RelatedGreaterThan)
ForeignObject.register_lookup(RelatedGreaterThanOrEqual)
ForeignObject.register_lookup(RelatedLessThanOrEqual)
ForeignObject.register_lookup(RelatedIsNull)
class ForeignKey(ForeignObject):
"""
Provide a many-to-one relation by adding a column to the local model
to hold the remote value.
By default ForeignKey will target the pk of the remote model but this
behavior can be changed by using the ``to_field`` argument.
"""
descriptor_class = ForeignKeyDeferredAttribute
# Field flags
many_to_many = False
many_to_one = True
one_to_many = False
one_to_one = False
rel_class = ManyToOneRel
empty_strings_allowed = False
default_error_messages = {
'invalid': _('%(model)s instance with %(field)s %(value)r does not exist.')
}
description = _("Foreign Key (type determined by related field)")
def __init__(self, to, on_delete, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
if not isinstance(to, str):
raise TypeError(
'%s(%r) is invalid. First parameter to ForeignKey must be '
'either a model, a model name, or the string %r' % (
self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
if not callable(on_delete):
raise TypeError('on_delete must be callable.')
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs.setdefault('db_index', True)
super().__init__(
to,
on_delete,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
from_fields=[RECURSIVE_RELATIONSHIP_CONSTANT],
to_fields=[to_field],
**kwargs,
)
self.db_constraint = db_constraint
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_on_delete(),
*self._check_unique(),
]
def _check_on_delete(self):
on_delete = getattr(self.remote_field, 'on_delete', None)
if on_delete == SET_NULL and not self.null:
return [
checks.Error(
'Field specifies on_delete=SET_NULL, but cannot be null.',
hint='Set null=True argument on the field, or change the on_delete rule.',
obj=self,
id='fields.E320',
)
]
elif on_delete == SET_DEFAULT and not self.has_default():
return [
checks.Error(
'Field specifies on_delete=SET_DEFAULT, but has no default value.',
hint='Set a default value, or change the on_delete rule.',
obj=self,
id='fields.E321',
)
]
else:
return []
def _check_unique(self, **kwargs):
return [
checks.Warning(
'Setting unique=True on a ForeignKey has the same effect as using a OneToOneField.',
hint='ForeignKey(unique=True) is usually better served by a OneToOneField.',
obj=self,
id='fields.W342',
)
] if self.unique else []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['to_fields']
del kwargs['from_fields']
# Handle the simpler arguments
if self.db_index:
del kwargs['db_index']
else:
kwargs['db_index'] = False
if self.db_constraint is not True:
kwargs['db_constraint'] = self.db_constraint
# Rel needs more work.
to_meta = getattr(self.remote_field.model, "_meta", None)
if self.remote_field.field_name and (
not to_meta or (to_meta.pk and self.remote_field.field_name != to_meta.pk.name)):
kwargs['to_field'] = self.remote_field.field_name
return name, path, args, kwargs
def to_python(self, value):
return self.target_field.to_python(value)
@property
def target_field(self):
return self.foreign_related_fields[0]
def get_reverse_path_info(self, filtered_relation=None):
"""Get path from the related model to this field's model."""
opts = self.model._meta
from_opts = self.remote_field.model._meta
return [PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=(opts.pk,),
join_field=self.remote_field,
m2m=not self.unique,
direct=False,
filtered_relation=filtered_relation,
)]
def validate(self, value, model_instance):
if self.remote_field.parent_link:
return
super().validate(value, model_instance)
if value is None:
return
using = router.db_for_read(self.remote_field.model, instance=model_instance)
qs = self.remote_field.model._base_manager.using(using).filter(
**{self.remote_field.field_name: value}
)
qs = qs.complex_filter(self.get_limit_choices_to())
if not qs.exists():
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={
'model': self.remote_field.model._meta.verbose_name, 'pk': value,
'field': self.remote_field.field_name, 'value': value,
}, # 'pk' is included for backwards compatibility
)
def resolve_related_fields(self):
related_fields = super().resolve_related_fields()
for from_field, to_field in related_fields:
if to_field and to_field.model != self.remote_field.model._meta.concrete_model:
raise exceptions.FieldError(
"'%s.%s' refers to field '%s' which is not local to model "
"'%s'." % (
self.model._meta.label,
self.name,
to_field.name,
self.remote_field.model._meta.concrete_model._meta.label,
)
)
return related_fields
def get_attname(self):
return '%s_id' % self.name
def get_attname_column(self):
attname = self.get_attname()
column = self.db_column or attname
return attname, column
def get_default(self):
"""Return the to_field if the default value is an object."""
field_default = super().get_default()
if isinstance(field_default, self.remote_field.model):
return getattr(field_default, self.target_field.attname)
return field_default
def get_db_prep_save(self, value, connection):
if value is None or (value == '' and
(not self.target_field.empty_strings_allowed or
connection.features.interprets_empty_strings_as_nulls)):
return None
else:
return self.target_field.get_db_prep_save(value, connection=connection)
def get_db_prep_value(self, value, connection, prepared=False):
return self.target_field.get_db_prep_value(value, connection, prepared)
def get_prep_value(self, value):
return self.target_field.get_prep_value(value)
def contribute_to_related_class(self, cls, related):
super().contribute_to_related_class(cls, related)
if self.remote_field.field_name is None:
self.remote_field.field_name = cls._meta.pk.name
def formfield(self, *, using=None, **kwargs):
if isinstance(self.remote_field.model, str):
raise ValueError("Cannot create form field for %r yet, because "
"its related model %r has not been loaded yet" %
(self.name, self.remote_field.model))
return super().formfield(**{
'form_class': forms.ModelChoiceField,
'queryset': self.remote_field.model._default_manager.using(using),
'to_field_name': self.remote_field.field_name,
**kwargs,
'blank': self.blank,
})
def db_check(self, connection):
return None
def db_type(self, connection):
return self.target_field.rel_db_type(connection=connection)
def db_parameters(self, connection):
return {"type": self.db_type(connection), "check": self.db_check(connection)}
def convert_empty_strings(self, value, expression, connection):
if (not value) and isinstance(value, str):
return None
return value
def get_db_converters(self, connection):
converters = super().get_db_converters(connection)
if connection.features.interprets_empty_strings_as_nulls:
converters += [self.convert_empty_strings]
return converters
def get_col(self, alias, output_field=None):
if output_field is None:
output_field = self.target_field
while isinstance(output_field, ForeignKey):
output_field = output_field.target_field
if output_field is self:
raise ValueError('Cannot resolve output_field.')
return super().get_col(alias, output_field)
class OneToOneField(ForeignKey):
"""
A OneToOneField is essentially the same as a ForeignKey, with the exception
that it always carries a "unique" constraint with it and the reverse
relation always returns the object pointed to (since there will only ever
be one), rather than returning a list.
"""
# Field flags
many_to_many = False
many_to_one = False
one_to_many = False
one_to_one = True
related_accessor_class = ReverseOneToOneDescriptor
forward_related_accessor_class = ForwardOneToOneDescriptor
rel_class = OneToOneRel
description = _("One-to-one relationship")
def __init__(self, to, on_delete, to_field=None, **kwargs):
kwargs['unique'] = True
super().__init__(to, on_delete, to_field=to_field, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if "unique" in kwargs:
del kwargs['unique']
return name, path, args, kwargs
def formfield(self, **kwargs):
if self.remote_field.parent_link:
return None
return super().formfield(**kwargs)
def save_form_data(self, instance, data):
if isinstance(data, self.remote_field.model):
setattr(instance, self.name, data)
else:
setattr(instance, self.attname, data)
# Remote field object must be cleared otherwise Model.save()
# will reassign attname using the related object pk.
if data is None:
setattr(instance, self.name, data)
def _check_unique(self, **kwargs):
# Override ForeignKey since check isn't applicable here.
return []
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type('Meta', (), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': _('%(from)s-%(to)s relationship') % {'from': from_, 'to': to},
'verbose_name_plural': _('%(from)s-%(to)s relationships') % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(name, (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
class ManyToManyField(RelatedField):
"""
Provide a many-to-many relation by using an intermediary model that
holds two ForeignKey fields pointed at the two sides of the relation.
Unless a ``through`` model was provided, ManyToManyField will use the
create_many_to_many_intermediary_model factory to automatically generate
the intermediary model.
"""
# Field flags
many_to_many = True
many_to_one = False
one_to_many = False
one_to_one = False
rel_class = ManyToManyRel
description = _("Many-to-many relationship")
def __init__(self, to, related_name=None, related_query_name=None,
limit_choices_to=None, symmetrical=None, through=None,
through_fields=None, db_constraint=True, db_table=None,
swappable=True, **kwargs):
try:
to._meta
except AttributeError:
if not isinstance(to, str):
raise TypeError(
'%s(%r) is invalid. First parameter to ManyToManyField '
'must be either a model, a model name, or the string %r' % (
self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
if symmetrical is None:
symmetrical = (to == RECURSIVE_RELATIONSHIP_CONSTANT)
if through is not None and db_table is not None:
raise ValueError(
'Cannot specify a db_table if an intermediary model is used.'
)
kwargs['rel'] = self.rel_class(
self, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
symmetrical=symmetrical,
through=through,
through_fields=through_fields,
db_constraint=db_constraint,
)
self.has_null_arg = 'null' in kwargs
super().__init__(
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
**kwargs,
)
self.db_table = db_table
self.swappable = swappable
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_unique(**kwargs),
*self._check_relationship_model(**kwargs),
*self._check_ignored_options(**kwargs),
*self._check_table_uniqueness(**kwargs),
]
def _check_unique(self, **kwargs):
if self.unique:
return [
checks.Error(
'ManyToManyFields cannot be unique.',
obj=self,
id='fields.E330',
)
]
return []
def _check_ignored_options(self, **kwargs):
warnings = []
if self.has_null_arg:
warnings.append(
checks.Warning(
'null has no effect on ManyToManyField.',
obj=self,
id='fields.W340',
)
)
if self._validators:
warnings.append(
checks.Warning(
'ManyToManyField does not support validators.',
obj=self,
id='fields.W341',
)
)
if self.remote_field.symmetrical and self._related_name:
warnings.append(
checks.Warning(
'related_name has no effect on ManyToManyField '
'with a symmetrical relationship, e.g. to "self".',
obj=self,
id='fields.W345',
)
)
return warnings
def _check_relationship_model(self, from_model=None, **kwargs):
if hasattr(self.remote_field.through, '_meta'):
qualified_model_name = "%s.%s" % (
self.remote_field.through._meta.app_label, self.remote_field.through.__name__)
else:
qualified_model_name = self.remote_field.through
errors = []
if self.remote_field.through not in self.opts.apps.get_models(include_auto_created=True):
# The relationship model is not installed.
errors.append(
checks.Error(
"Field specifies a many-to-many relation through model "
"'%s', which has not been installed." % qualified_model_name,
obj=self,
id='fields.E331',
)
)
else:
assert from_model is not None, (
"ManyToManyField with intermediate "
"tables cannot be checked if you don't pass the model "
"where the field is attached to."
)
# Set some useful local variables
to_model = resolve_relation(from_model, self.remote_field.model)
from_model_name = from_model._meta.object_name
if isinstance(to_model, str):
to_model_name = to_model
else:
to_model_name = to_model._meta.object_name
relationship_model_name = self.remote_field.through._meta.object_name
self_referential = from_model == to_model
# Count foreign keys in intermediate model
if self_referential:
seen_self = sum(
from_model == getattr(field.remote_field, 'model', None)
for field in self.remote_field.through._meta.fields
)
if seen_self > 2 and not self.remote_field.through_fields:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it has more than two foreign keys "
"to '%s', which is ambiguous. You must specify "
"which two foreign keys Django should use via the "
"through_fields keyword argument." % (self, from_model_name),
hint="Use through_fields to specify which two foreign keys Django should use.",
obj=self.remote_field.through,
id='fields.E333',
)
)
else:
# Count foreign keys in relationship model
seen_from = sum(
from_model == getattr(field.remote_field, 'model', None)
for field in self.remote_field.through._meta.fields
)
seen_to = sum(
to_model == getattr(field.remote_field, 'model', None)
for field in self.remote_field.through._meta.fields
)
if seen_from > 1 and not self.remote_field.through_fields:
errors.append(
checks.Error(
("The model is used as an intermediate model by "
"'%s', but it has more than one foreign key "
"from '%s', which is ambiguous. You must specify "
"which foreign key Django should use via the "
"through_fields keyword argument.") % (self, from_model_name),
hint=(
'If you want to create a recursive relationship, '
'use ManyToManyField("%s", through="%s").'
) % (
RECURSIVE_RELATIONSHIP_CONSTANT,
relationship_model_name,
),
obj=self,
id='fields.E334',
)
)
if seen_to > 1 and not self.remote_field.through_fields:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it has more than one foreign key "
"to '%s', which is ambiguous. You must specify "
"which foreign key Django should use via the "
"through_fields keyword argument." % (self, to_model_name),
hint=(
'If you want to create a recursive relationship, '
'use ManyToManyField("%s", through="%s").'
) % (
RECURSIVE_RELATIONSHIP_CONSTANT,
relationship_model_name,
),
obj=self,
id='fields.E335',
)
)
if seen_from == 0 or seen_to == 0:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it does not have a foreign key to '%s' or '%s'." % (
self, from_model_name, to_model_name
),
obj=self.remote_field.through,
id='fields.E336',
)
)
# Validate `through_fields`.
if self.remote_field.through_fields is not None:
# Validate that we're given an iterable of at least two items
# and that none of them is "falsy".
if not (len(self.remote_field.through_fields) >= 2 and
self.remote_field.through_fields[0] and self.remote_field.through_fields[1]):
errors.append(
checks.Error(
"Field specifies 'through_fields' but does not provide "
"the names of the two link fields that should be used "
"for the relation through model '%s'." % qualified_model_name,
hint="Make sure you specify 'through_fields' as through_fields=('field1', 'field2')",
obj=self,
id='fields.E337',
)
)
# Validate the given through fields -- they should be actual
# fields on the through model, and also be foreign keys to the
# expected models.
else:
assert from_model is not None, (
"ManyToManyField with intermediate "
"tables cannot be checked if you don't pass the model "
"where the field is attached to."
)
source, through, target = from_model, self.remote_field.through, self.remote_field.model
source_field_name, target_field_name = self.remote_field.through_fields[:2]
for field_name, related_model in ((source_field_name, source),
(target_field_name, target)):
possible_field_names = []
for f in through._meta.fields:
if hasattr(f, 'remote_field') and getattr(f.remote_field, 'model', None) == related_model:
possible_field_names.append(f.name)
if possible_field_names:
hint = "Did you mean one of the following foreign keys to '%s': %s?" % (
related_model._meta.object_name,
', '.join(possible_field_names),
)
else:
hint = None
try:
field = through._meta.get_field(field_name)
except exceptions.FieldDoesNotExist:
errors.append(
checks.Error(
"The intermediary model '%s' has no field '%s'."
% (qualified_model_name, field_name),
hint=hint,
obj=self,
id='fields.E338',
)
)
else:
if not (hasattr(field, 'remote_field') and
getattr(field.remote_field, 'model', None) == related_model):
errors.append(
checks.Error(
"'%s.%s' is not a foreign key to '%s'." % (
through._meta.object_name, field_name,
related_model._meta.object_name,
),
hint=hint,
obj=self,
id='fields.E339',
)
)
return errors
def _check_table_uniqueness(self, **kwargs):
if isinstance(self.remote_field.through, str) or not self.remote_field.through._meta.managed:
return []
registered_tables = {
model._meta.db_table: model
for model in self.opts.apps.get_models(include_auto_created=True)
if model != self.remote_field.through and model._meta.managed
}
m2m_db_table = self.m2m_db_table()
model = registered_tables.get(m2m_db_table)
# The second condition allows multiple m2m relations on a model if
# some point to a through model that proxies another through model.
if model and model._meta.concrete_model != self.remote_field.through._meta.concrete_model:
if model._meta.auto_created:
def _get_field_name(model):
for field in model._meta.auto_created._meta.many_to_many:
if field.remote_field.through is model:
return field.name
opts = model._meta.auto_created._meta
clashing_obj = '%s.%s' % (opts.label, _get_field_name(model))
else:
clashing_obj = model._meta.label
if settings.DATABASE_ROUTERS:
error_class, error_id = checks.Warning, 'fields.W344'
error_hint = (
'You have configured settings.DATABASE_ROUTERS. Verify '
'that the table of %r is correctly routed to a separate '
'database.' % clashing_obj
)
else:
error_class, error_id = checks.Error, 'fields.E340'
error_hint = None
return [
error_class(
"The field's intermediary table '%s' clashes with the "
"table name of '%s'." % (m2m_db_table, clashing_obj),
obj=self,
hint=error_hint,
id=error_id,
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
# Handle the simpler arguments.
if self.db_table is not None:
kwargs['db_table'] = self.db_table
if self.remote_field.db_constraint is not True:
kwargs['db_constraint'] = self.remote_field.db_constraint
# Rel needs more work.
if isinstance(self.remote_field.model, str):
kwargs['to'] = self.remote_field.model
else:
kwargs['to'] = self.remote_field.model._meta.label
if getattr(self.remote_field, 'through', None) is not None:
if isinstance(self.remote_field.through, str):
kwargs['through'] = self.remote_field.through
elif not self.remote_field.through._meta.auto_created:
kwargs['through'] = self.remote_field.through._meta.label
# If swappable is True, then see if we're actually pointing to the target
# of a swap.
swappable_setting = self.swappable_setting
if swappable_setting is not None:
# If it's already a settings reference, error.
if hasattr(kwargs['to'], "setting_name"):
if kwargs['to'].setting_name != swappable_setting:
raise ValueError(
"Cannot deconstruct a ManyToManyField pointing to a "
"model that is swapped in place of more than one model "
"(%s and %s)" % (kwargs['to'].setting_name, swappable_setting)
)
kwargs['to'] = SettingsReference(
kwargs['to'],
swappable_setting,
)
return name, path, args, kwargs
def _get_path_info(self, direct=False, filtered_relation=None):
"""Called by both direct and indirect m2m traversal."""
int_model = self.remote_field.through
linkfield1 = int_model._meta.get_field(self.m2m_field_name())
linkfield2 = int_model._meta.get_field(self.m2m_reverse_field_name())
if direct:
join1infos = linkfield1.reverse_path_infos
if filtered_relation:
join2infos = linkfield2.get_path_info(filtered_relation)
else:
join2infos = linkfield2.path_infos
else:
join1infos = linkfield2.reverse_path_infos
if filtered_relation:
join2infos = linkfield1.get_path_info(filtered_relation)
else:
join2infos = linkfield1.path_infos
# Get join infos between the last model of join 1 and the first model
# of join 2. Assume the only reason these may differ is due to model
# inheritance.
join1_final = join1infos[-1].to_opts
join2_initial = join2infos[0].from_opts
if join1_final is join2_initial:
intermediate_infos = []
elif issubclass(join1_final.model, join2_initial.model):
intermediate_infos = join1_final.get_path_to_parent(join2_initial.model)
else:
intermediate_infos = join2_initial.get_path_from_parent(join1_final.model)
return [*join1infos, *intermediate_infos, *join2infos]
def get_path_info(self, filtered_relation=None):
return self._get_path_info(direct=True, filtered_relation=filtered_relation)
@cached_property
def path_infos(self):
return self.get_path_info()
def get_reverse_path_info(self, filtered_relation=None):
return self._get_path_info(direct=False, filtered_relation=filtered_relation)
@cached_property
def reverse_path_infos(self):
return self.get_reverse_path_info()
def _get_m2m_db_table(self, opts):
"""
Function that can be curried to provide the m2m table name for this
relation.
"""
if self.remote_field.through is not None:
return self.remote_field.through._meta.db_table
elif self.db_table:
return self.db_table
else:
m2m_table_name = '%s_%s' % (utils.strip_quotes(opts.db_table), self.name)
return utils.truncate_name(m2m_table_name, connection.ops.max_name_length())
def _get_m2m_attr(self, related, attr):
"""
Function that can be curried to provide the source accessor or DB
column name for the m2m table.
"""
cache_attr = '_m2m_%s_cache' % attr
if hasattr(self, cache_attr):
return getattr(self, cache_attr)
if self.remote_field.through_fields is not None:
link_field_name = self.remote_field.through_fields[0]
else:
link_field_name = None
for f in self.remote_field.through._meta.fields:
if (f.is_relation and f.remote_field.model == related.related_model and
(link_field_name is None or link_field_name == f.name)):
setattr(self, cache_attr, getattr(f, attr))
return getattr(self, cache_attr)
def _get_m2m_reverse_attr(self, related, attr):
"""
Function that can be curried to provide the related accessor or DB
column name for the m2m table.
"""
cache_attr = '_m2m_reverse_%s_cache' % attr
if hasattr(self, cache_attr):
return getattr(self, cache_attr)
found = False
if self.remote_field.through_fields is not None:
link_field_name = self.remote_field.through_fields[1]
else:
link_field_name = None
for f in self.remote_field.through._meta.fields:
if f.is_relation and f.remote_field.model == related.model:
if link_field_name is None and related.related_model == related.model:
# If this is an m2m-intermediate to self,
# the first foreign key you find will be
# the source column. Keep searching for
# the second foreign key.
if found:
setattr(self, cache_attr, getattr(f, attr))
break
else:
found = True
elif link_field_name is None or link_field_name == f.name:
setattr(self, cache_attr, getattr(f, attr))
break
return getattr(self, cache_attr)
def contribute_to_class(self, cls, name, **kwargs):
# To support multiple relations to self, it's useful to have a non-None
# related name on symmetrical relations for internal reasons. The
# concept doesn't make a lot of sense externally ("you want me to
# specify *what* on my non-reversible relation?!"), so we set it up
# automatically. The funky name reduces the chance of an accidental
# clash.
if self.remote_field.symmetrical and (
self.remote_field.model == RECURSIVE_RELATIONSHIP_CONSTANT or
self.remote_field.model == cls._meta.object_name
):
self.remote_field.related_name = "%s_rel_+" % name
elif self.remote_field.is_hidden():
# If the backwards relation is disabled, replace the original
# related_name with one generated from the m2m field name. Django
# still uses backwards relations internally and we need to avoid
# clashes between multiple m2m fields with related_name == '+'.
self.remote_field.related_name = '_%s_%s_%s_+' % (
cls._meta.app_label,
cls.__name__.lower(),
name,
)
super().contribute_to_class(cls, name, **kwargs)
# The intermediate m2m model is not auto created if:
# 1) There is a manually specified intermediate, or
# 2) The class owning the m2m field is abstract.
# 3) The class owning the m2m field has been swapped out.
if not cls._meta.abstract:
if self.remote_field.through:
def resolve_through_model(_, model, field):
field.remote_field.through = model
lazy_related_operation(resolve_through_model, cls, self.remote_field.through, field=self)
elif not cls._meta.swapped:
self.remote_field.through = create_many_to_many_intermediary_model(self, cls)
# Add the descriptor for the m2m relation.
setattr(cls, self.name, ManyToManyDescriptor(self.remote_field, reverse=False))
# Set up the accessor for the m2m table name for the relation.
self.m2m_db_table = partial(self._get_m2m_db_table, cls._meta)
def contribute_to_related_class(self, cls, related):
# Internal M2Ms (i.e., those with a related name ending with '+')
# and swapped models don't get a related descriptor.
if not self.remote_field.is_hidden() and not related.related_model._meta.swapped:
setattr(cls, related.get_accessor_name(), ManyToManyDescriptor(self.remote_field, reverse=True))
# Set up the accessors for the column names on the m2m table.
self.m2m_column_name = partial(self._get_m2m_attr, related, 'column')
self.m2m_reverse_name = partial(self._get_m2m_reverse_attr, related, 'column')
self.m2m_field_name = partial(self._get_m2m_attr, related, 'name')
self.m2m_reverse_field_name = partial(self._get_m2m_reverse_attr, related, 'name')
get_m2m_rel = partial(self._get_m2m_attr, related, 'remote_field')
self.m2m_target_field_name = lambda: get_m2m_rel().field_name
get_m2m_reverse_rel = partial(self._get_m2m_reverse_attr, related, 'remote_field')
self.m2m_reverse_target_field_name = lambda: get_m2m_reverse_rel().field_name
def set_attributes_from_rel(self):
pass
def value_from_object(self, obj):
return [] if obj.pk is None else list(getattr(obj, self.attname).all())
def save_form_data(self, instance, data):
getattr(instance, self.attname).set(data)
def formfield(self, *, using=None, **kwargs):
defaults = {
'form_class': forms.ModelMultipleChoiceField,
'queryset': self.remote_field.model._default_manager.using(using),
**kwargs,
}
# If initial is passed in, it's a list of related objects, but the
# MultipleChoiceField takes a list of IDs.
if defaults.get('initial') is not None:
initial = defaults['initial']
if callable(initial):
initial = initial()
defaults['initial'] = [i.pk for i in initial]
return super().formfield(**defaults)
def db_check(self, connection):
return None
def db_type(self, connection):
# A ManyToManyField is not represented by a single column,
# so return None.
return None
def db_parameters(self, connection):
return {"type": None, "check": None}
|
cdd584883b9002f5087e5b8acc54a57ed4f6415f463d7c8410f33f1078fe71c3 | """
Accessors for related objects.
When a field defines a relation between two models, each model class provides
an attribute to access related instances of the other model class (unless the
reverse accessor has been disabled with related_name='+').
Accessors are implemented as descriptors in order to customize access and
assignment. This module defines the descriptor classes.
Forward accessors follow foreign keys. Reverse accessors trace them back. For
example, with the following models::
class Parent(Model):
pass
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``child.parent`` is a forward many-to-one relation. ``parent.children`` is a
reverse many-to-one relation.
There are three types of relations (many-to-one, one-to-one, and many-to-many)
and two directions (forward and reverse) for a total of six combinations.
1. Related instance on the forward side of a many-to-one relation:
``ForwardManyToOneDescriptor``.
Uniqueness of foreign key values is irrelevant to accessing the related
instance, making the many-to-one and one-to-one cases identical as far as
the descriptor is concerned. The constraint is checked upstream (unicity
validation in forms) or downstream (unique indexes in the database).
2. Related instance on the forward side of a one-to-one
relation: ``ForwardOneToOneDescriptor``.
It avoids querying the database when accessing the parent link field in
a multi-table inheritance scenario.
3. Related instance on the reverse side of a one-to-one relation:
``ReverseOneToOneDescriptor``.
One-to-one relations are asymmetrical, despite the apparent symmetry of the
name, because they're implemented in the database with a foreign key from
one table to another. As a consequence ``ReverseOneToOneDescriptor`` is
slightly different from ``ForwardManyToOneDescriptor``.
4. Related objects manager for related instances on the reverse side of a
many-to-one relation: ``ReverseManyToOneDescriptor``.
Unlike the previous two classes, this one provides access to a collection
of objects. It returns a manager rather than an instance.
5. Related objects manager for related instances on the forward or reverse
sides of a many-to-many relation: ``ManyToManyDescriptor``.
Many-to-many relations are symmetrical. The syntax of Django models
requires declaring them on one side but that's an implementation detail.
They could be declared on the other side without any change in behavior.
Therefore the forward and reverse descriptors can be the same.
If you're looking for ``ForwardManyToManyDescriptor`` or
``ReverseManyToManyDescriptor``, use ``ManyToManyDescriptor`` instead.
"""
from django.core.exceptions import FieldError
from django.db import connections, router, transaction
from django.db.models import Q, signals
from django.db.models.query import QuerySet
from django.db.models.query_utils import DeferredAttribute
from django.db.models.utils import resolve_callables
from django.utils.functional import cached_property
class ForeignKeyDeferredAttribute(DeferredAttribute):
def __set__(self, instance, value):
if instance.__dict__.get(self.field.attname) != value and self.field.is_cached(instance):
self.field.delete_cached_value(instance)
instance.__dict__[self.field.attname] = value
class ForwardManyToOneDescriptor:
"""
Accessor to the related object on the forward side of a many-to-one or
one-to-one (via ForwardOneToOneDescriptor subclass) relation.
In the example::
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``Child.parent`` is a ``ForwardManyToOneDescriptor`` instance.
"""
def __init__(self, field_with_rel):
self.field = field_with_rel
@cached_property
def RelatedObjectDoesNotExist(self):
# The exception can't be created at initialization time since the
# related model might not be resolved yet; `self.field.model` might
# still be a string model reference.
return type(
'RelatedObjectDoesNotExist',
(self.field.remote_field.model.DoesNotExist, AttributeError), {
'__module__': self.field.model.__module__,
'__qualname__': '%s.%s.RelatedObjectDoesNotExist' % (
self.field.model.__qualname__,
self.field.name,
),
}
)
def is_cached(self, instance):
return self.field.is_cached(instance)
def get_queryset(self, **hints):
return self.field.remote_field.model._base_manager.db_manager(hints=hints).all()
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = self.get_queryset()
queryset._add_hints(instance=instances[0])
rel_obj_attr = self.field.get_foreign_related_value
instance_attr = self.field.get_local_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
related_field = self.field.foreign_related_fields[0]
remote_field = self.field.remote_field
# FIXME: This will need to be revisited when we introduce support for
# composite fields. In the meantime we take this practical approach to
# solve a regression on 1.6 when the reverse manager in hidden
# (related_name ends with a '+'). Refs #21410.
# The check for len(...) == 1 is a special case that allows the query
# to be join-less and smaller. Refs #21760.
if remote_field.is_hidden() or len(self.field.foreign_related_fields) == 1:
query = {'%s__in' % related_field.name: {instance_attr(inst)[0] for inst in instances}}
else:
query = {'%s__in' % self.field.related_query_name(): instances}
queryset = queryset.filter(**query)
# Since we're going to assign directly in the cache,
# we must manage the reverse relation cache manually.
if not remote_field.multiple:
for rel_obj in queryset:
instance = instances_dict[rel_obj_attr(rel_obj)]
remote_field.set_cached_value(rel_obj, instance)
return queryset, rel_obj_attr, instance_attr, True, self.field.get_cache_name(), False
def get_object(self, instance):
qs = self.get_queryset(instance=instance)
# Assuming the database enforces foreign keys, this won't fail.
return qs.get(self.field.get_reverse_related_filter(instance))
def __get__(self, instance, cls=None):
"""
Get the related instance through the forward relation.
With the example above, when getting ``child.parent``:
- ``self`` is the descriptor managing the ``parent`` attribute
- ``instance`` is the ``child`` instance
- ``cls`` is the ``Child`` class (we don't need it)
"""
if instance is None:
return self
# The related instance is loaded from the database and then cached
# by the field on the model instance state. It can also be pre-cached
# by the reverse accessor (ReverseOneToOneDescriptor).
try:
rel_obj = self.field.get_cached_value(instance)
except KeyError:
has_value = None not in self.field.get_local_related_value(instance)
ancestor_link = instance._meta.get_ancestor_link(self.field.model) if has_value else None
if ancestor_link and ancestor_link.is_cached(instance):
# An ancestor link will exist if this field is defined on a
# multi-table inheritance parent of the instance's class.
ancestor = ancestor_link.get_cached_value(instance)
# The value might be cached on an ancestor if the instance
# originated from walking down the inheritance chain.
rel_obj = self.field.get_cached_value(ancestor, default=None)
else:
rel_obj = None
if rel_obj is None and has_value:
rel_obj = self.get_object(instance)
remote_field = self.field.remote_field
# If this is a one-to-one relation, set the reverse accessor
# cache on the related object to the current instance to avoid
# an extra SQL query if it's accessed later on.
if not remote_field.multiple:
remote_field.set_cached_value(rel_obj, instance)
self.field.set_cached_value(instance, rel_obj)
if rel_obj is None and not self.field.null:
raise self.RelatedObjectDoesNotExist(
"%s has no %s." % (self.field.model.__name__, self.field.name)
)
else:
return rel_obj
def __set__(self, instance, value):
"""
Set the related instance through the forward relation.
With the example above, when setting ``child.parent = parent``:
- ``self`` is the descriptor managing the ``parent`` attribute
- ``instance`` is the ``child`` instance
- ``value`` is the ``parent`` instance on the right of the equal sign
"""
# An object must be an instance of the related class.
if value is not None and not isinstance(value, self.field.remote_field.model._meta.concrete_model):
raise ValueError(
'Cannot assign "%r": "%s.%s" must be a "%s" instance.' % (
value,
instance._meta.object_name,
self.field.name,
self.field.remote_field.model._meta.object_name,
)
)
elif value is not None:
if instance._state.db is None:
instance._state.db = router.db_for_write(instance.__class__, instance=value)
if value._state.db is None:
value._state.db = router.db_for_write(value.__class__, instance=instance)
if not router.allow_relation(value, instance):
raise ValueError('Cannot assign "%r": the current database router prevents this relation.' % value)
remote_field = self.field.remote_field
# If we're setting the value of a OneToOneField to None, we need to clear
# out the cache on any old related object. Otherwise, deleting the
# previously-related object will also cause this object to be deleted,
# which is wrong.
if value is None:
# Look up the previously-related object, which may still be available
# since we've not yet cleared out the related field.
# Use the cache directly, instead of the accessor; if we haven't
# populated the cache, then we don't care - we're only accessing
# the object to invalidate the accessor cache, so there's no
# need to populate the cache just to expire it again.
related = self.field.get_cached_value(instance, default=None)
# If we've got an old related object, we need to clear out its
# cache. This cache also might not exist if the related object
# hasn't been accessed yet.
if related is not None:
remote_field.set_cached_value(related, None)
for lh_field, rh_field in self.field.related_fields:
setattr(instance, lh_field.attname, None)
# Set the values of the related field.
else:
for lh_field, rh_field in self.field.related_fields:
setattr(instance, lh_field.attname, getattr(value, rh_field.attname))
# Set the related instance cache used by __get__ to avoid an SQL query
# when accessing the attribute we just set.
self.field.set_cached_value(instance, value)
# If this is a one-to-one relation, set the reverse accessor cache on
# the related object to the current instance to avoid an extra SQL
# query if it's accessed later on.
if value is not None and not remote_field.multiple:
remote_field.set_cached_value(value, instance)
def __reduce__(self):
"""
Pickling should return the instance attached by self.field on the
model, not a new copy of that descriptor. Use getattr() to retrieve
the instance directly from the model.
"""
return getattr, (self.field.model, self.field.name)
class ForwardOneToOneDescriptor(ForwardManyToOneDescriptor):
"""
Accessor to the related object on the forward side of a one-to-one relation.
In the example::
class Restaurant(Model):
place = OneToOneField(Place, related_name='restaurant')
``Restaurant.place`` is a ``ForwardOneToOneDescriptor`` instance.
"""
def get_object(self, instance):
if self.field.remote_field.parent_link:
deferred = instance.get_deferred_fields()
# Because it's a parent link, all the data is available in the
# instance, so populate the parent model with this data.
rel_model = self.field.remote_field.model
fields = [field.attname for field in rel_model._meta.concrete_fields]
# If any of the related model's fields are deferred, fallback to
# fetching all fields from the related model. This avoids a query
# on the related model for every deferred field.
if not any(field in fields for field in deferred):
kwargs = {field: getattr(instance, field) for field in fields}
obj = rel_model(**kwargs)
obj._state.adding = instance._state.adding
obj._state.db = instance._state.db
return obj
return super().get_object(instance)
def __set__(self, instance, value):
super().__set__(instance, value)
# If the primary key is a link to a parent model and a parent instance
# is being set, update the value of the inherited pk(s).
if self.field.primary_key and self.field.remote_field.parent_link:
opts = instance._meta
# Inherited primary key fields from this object's base classes.
inherited_pk_fields = [
field for field in opts.concrete_fields
if field.primary_key and field.remote_field
]
for field in inherited_pk_fields:
rel_model_pk_name = field.remote_field.model._meta.pk.attname
raw_value = getattr(value, rel_model_pk_name) if value is not None else None
setattr(instance, rel_model_pk_name, raw_value)
class ReverseOneToOneDescriptor:
"""
Accessor to the related object on the reverse side of a one-to-one
relation.
In the example::
class Restaurant(Model):
place = OneToOneField(Place, related_name='restaurant')
``Place.restaurant`` is a ``ReverseOneToOneDescriptor`` instance.
"""
def __init__(self, related):
# Following the example above, `related` is an instance of OneToOneRel
# which represents the reverse restaurant field (place.restaurant).
self.related = related
@cached_property
def RelatedObjectDoesNotExist(self):
# The exception isn't created at initialization time for the sake of
# consistency with `ForwardManyToOneDescriptor`.
return type(
'RelatedObjectDoesNotExist',
(self.related.related_model.DoesNotExist, AttributeError), {
'__module__': self.related.model.__module__,
'__qualname__': '%s.%s.RelatedObjectDoesNotExist' % (
self.related.model.__qualname__,
self.related.name,
)
},
)
def is_cached(self, instance):
return self.related.is_cached(instance)
def get_queryset(self, **hints):
return self.related.related_model._base_manager.db_manager(hints=hints).all()
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = self.get_queryset()
queryset._add_hints(instance=instances[0])
rel_obj_attr = self.related.field.get_local_related_value
instance_attr = self.related.field.get_foreign_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
query = {'%s__in' % self.related.field.name: instances}
queryset = queryset.filter(**query)
# Since we're going to assign directly in the cache,
# we must manage the reverse relation cache manually.
for rel_obj in queryset:
instance = instances_dict[rel_obj_attr(rel_obj)]
self.related.field.set_cached_value(rel_obj, instance)
return queryset, rel_obj_attr, instance_attr, True, self.related.get_cache_name(), False
def __get__(self, instance, cls=None):
"""
Get the related instance through the reverse relation.
With the example above, when getting ``place.restaurant``:
- ``self`` is the descriptor managing the ``restaurant`` attribute
- ``instance`` is the ``place`` instance
- ``cls`` is the ``Place`` class (unused)
Keep in mind that ``Restaurant`` holds the foreign key to ``Place``.
"""
if instance is None:
return self
# The related instance is loaded from the database and then cached
# by the field on the model instance state. It can also be pre-cached
# by the forward accessor (ForwardManyToOneDescriptor).
try:
rel_obj = self.related.get_cached_value(instance)
except KeyError:
related_pk = instance.pk
if related_pk is None:
rel_obj = None
else:
filter_args = self.related.field.get_forward_related_filter(instance)
try:
rel_obj = self.get_queryset(instance=instance).get(**filter_args)
except self.related.related_model.DoesNotExist:
rel_obj = None
else:
# Set the forward accessor cache on the related object to
# the current instance to avoid an extra SQL query if it's
# accessed later on.
self.related.field.set_cached_value(rel_obj, instance)
self.related.set_cached_value(instance, rel_obj)
if rel_obj is None:
raise self.RelatedObjectDoesNotExist(
"%s has no %s." % (
instance.__class__.__name__,
self.related.get_accessor_name()
)
)
else:
return rel_obj
def __set__(self, instance, value):
"""
Set the related instance through the reverse relation.
With the example above, when setting ``place.restaurant = restaurant``:
- ``self`` is the descriptor managing the ``restaurant`` attribute
- ``instance`` is the ``place`` instance
- ``value`` is the ``restaurant`` instance on the right of the equal sign
Keep in mind that ``Restaurant`` holds the foreign key to ``Place``.
"""
# The similarity of the code below to the code in
# ForwardManyToOneDescriptor is annoying, but there's a bunch
# of small differences that would make a common base class convoluted.
if value is None:
# Update the cached related instance (if any) & clear the cache.
# Following the example above, this would be the cached
# ``restaurant`` instance (if any).
rel_obj = self.related.get_cached_value(instance, default=None)
if rel_obj is not None:
# Remove the ``restaurant`` instance from the ``place``
# instance cache.
self.related.delete_cached_value(instance)
# Set the ``place`` field on the ``restaurant``
# instance to None.
setattr(rel_obj, self.related.field.name, None)
elif not isinstance(value, self.related.related_model):
# An object must be an instance of the related class.
raise ValueError(
'Cannot assign "%r": "%s.%s" must be a "%s" instance.' % (
value,
instance._meta.object_name,
self.related.get_accessor_name(),
self.related.related_model._meta.object_name,
)
)
else:
if instance._state.db is None:
instance._state.db = router.db_for_write(instance.__class__, instance=value)
if value._state.db is None:
value._state.db = router.db_for_write(value.__class__, instance=instance)
if not router.allow_relation(value, instance):
raise ValueError('Cannot assign "%r": the current database router prevents this relation.' % value)
related_pk = tuple(getattr(instance, field.attname) for field in self.related.field.foreign_related_fields)
# Set the value of the related field to the value of the related object's related field
for index, field in enumerate(self.related.field.local_related_fields):
setattr(value, field.attname, related_pk[index])
# Set the related instance cache used by __get__ to avoid an SQL query
# when accessing the attribute we just set.
self.related.set_cached_value(instance, value)
# Set the forward accessor cache on the related object to the current
# instance to avoid an extra SQL query if it's accessed later on.
self.related.field.set_cached_value(value, instance)
def __reduce__(self):
# Same purpose as ForwardManyToOneDescriptor.__reduce__().
return getattr, (self.related.model, self.related.name)
class ReverseManyToOneDescriptor:
"""
Accessor to the related objects manager on the reverse side of a
many-to-one relation.
In the example::
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``Parent.children`` is a ``ReverseManyToOneDescriptor`` instance.
Most of the implementation is delegated to a dynamically defined manager
class built by ``create_forward_many_to_many_manager()`` defined below.
"""
def __init__(self, rel):
self.rel = rel
self.field = rel.field
@cached_property
def related_manager_cache_key(self):
# Being able to access the manager instance precludes it from being
# hidden. The rel's accessor name is used to allow multiple managers
# to the same model to coexist. e.g. post.attached_comment_set and
# post.attached_link_set are separately cached.
return self.rel.get_cache_name()
@cached_property
def related_manager_cls(self):
related_model = self.rel.related_model
return create_reverse_many_to_one_manager(
related_model._default_manager.__class__,
self.rel,
)
def __get__(self, instance, cls=None):
"""
Get the related objects through the reverse relation.
With the example above, when getting ``parent.children``:
- ``self`` is the descriptor managing the ``children`` attribute
- ``instance`` is the ``parent`` instance
- ``cls`` is the ``Parent`` class (unused)
"""
if instance is None:
return self
key = self.related_manager_cache_key
instance_cache = instance._state.related_managers_cache
if key not in instance_cache:
instance_cache[key] = self.related_manager_cls(instance)
return instance_cache[key]
def _get_set_deprecation_msg_params(self):
return (
'reverse side of a related set',
self.rel.get_accessor_name(),
)
def __set__(self, instance, value):
raise TypeError(
'Direct assignment to the %s is prohibited. Use %s.set() instead.'
% self._get_set_deprecation_msg_params(),
)
def create_reverse_many_to_one_manager(superclass, rel):
"""
Create a manager for the reverse side of a many-to-one relation.
This manager subclasses another manager, generally the default manager of
the related model, and adds behaviors specific to many-to-one relations.
"""
class RelatedManager(superclass):
def __init__(self, instance):
super().__init__()
self.instance = instance
self.model = rel.related_model
self.field = rel.field
self.core_filters = {self.field.name: instance}
def __call__(self, *, manager):
manager = getattr(self.model, manager)
manager_class = create_reverse_many_to_one_manager(manager.__class__, rel)
return manager_class(self.instance)
do_not_call_in_templates = True
def _apply_rel_filters(self, queryset):
"""
Filter the queryset for the instance this manager is bound to.
"""
db = self._db or router.db_for_read(self.model, instance=self.instance)
empty_strings_as_null = connections[db].features.interprets_empty_strings_as_nulls
queryset._add_hints(instance=self.instance)
if self._db:
queryset = queryset.using(self._db)
queryset._defer_next_filter = True
queryset = queryset.filter(**self.core_filters)
for field in self.field.foreign_related_fields:
val = getattr(self.instance, field.attname)
if val is None or (val == '' and empty_strings_as_null):
return queryset.none()
if self.field.many_to_one:
# Guard against field-like objects such as GenericRelation
# that abuse create_reverse_many_to_one_manager() with reverse
# one-to-many relationships instead and break known related
# objects assignment.
try:
target_field = self.field.target_field
except FieldError:
# The relationship has multiple target fields. Use a tuple
# for related object id.
rel_obj_id = tuple([
getattr(self.instance, target_field.attname)
for target_field in self.field.path_infos[-1].target_fields
])
else:
rel_obj_id = getattr(self.instance, target_field.attname)
queryset._known_related_objects = {self.field: {rel_obj_id: self.instance}}
return queryset
def _remove_prefetched_objects(self):
try:
self.instance._prefetched_objects_cache.pop(self.field.remote_field.get_cache_name())
except (AttributeError, KeyError):
pass # nothing to clear from cache
def get_queryset(self):
try:
return self.instance._prefetched_objects_cache[self.field.remote_field.get_cache_name()]
except (AttributeError, KeyError):
queryset = super().get_queryset()
return self._apply_rel_filters(queryset)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = super().get_queryset()
queryset._add_hints(instance=instances[0])
queryset = queryset.using(queryset._db or self._db)
rel_obj_attr = self.field.get_local_related_value
instance_attr = self.field.get_foreign_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
query = {'%s__in' % self.field.name: instances}
queryset = queryset.filter(**query)
# Since we just bypassed this class' get_queryset(), we must manage
# the reverse relation manually.
for rel_obj in queryset:
if not self.field.is_cached(rel_obj):
instance = instances_dict[rel_obj_attr(rel_obj)]
setattr(rel_obj, self.field.name, instance)
cache_name = self.field.remote_field.get_cache_name()
return queryset, rel_obj_attr, instance_attr, False, cache_name, False
def add(self, *objs, bulk=True):
self._remove_prefetched_objects()
db = router.db_for_write(self.model, instance=self.instance)
def check_and_update_obj(obj):
if not isinstance(obj, self.model):
raise TypeError("'%s' instance expected, got %r" % (
self.model._meta.object_name, obj,
))
setattr(obj, self.field.name, self.instance)
if bulk:
pks = []
for obj in objs:
check_and_update_obj(obj)
if obj._state.adding or obj._state.db != db:
raise ValueError(
"%r instance isn't saved. Use bulk=False or save "
"the object first." % obj
)
pks.append(obj.pk)
self.model._base_manager.using(db).filter(pk__in=pks).update(**{
self.field.name: self.instance,
})
else:
with transaction.atomic(using=db, savepoint=False):
for obj in objs:
check_and_update_obj(obj)
obj.save()
add.alters_data = True
def create(self, **kwargs):
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).create(**kwargs)
create.alters_data = True
def get_or_create(self, **kwargs):
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).get_or_create(**kwargs)
get_or_create.alters_data = True
def update_or_create(self, **kwargs):
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).update_or_create(**kwargs)
update_or_create.alters_data = True
# remove() and clear() are only provided if the ForeignKey can have a value of null.
if rel.field.null:
def remove(self, *objs, bulk=True):
if not objs:
return
val = self.field.get_foreign_related_value(self.instance)
old_ids = set()
for obj in objs:
if not isinstance(obj, self.model):
raise TypeError("'%s' instance expected, got %r" % (
self.model._meta.object_name, obj,
))
# Is obj actually part of this descriptor set?
if self.field.get_local_related_value(obj) == val:
old_ids.add(obj.pk)
else:
raise self.field.remote_field.model.DoesNotExist(
"%r is not related to %r." % (obj, self.instance)
)
self._clear(self.filter(pk__in=old_ids), bulk)
remove.alters_data = True
def clear(self, *, bulk=True):
self._clear(self, bulk)
clear.alters_data = True
def _clear(self, queryset, bulk):
self._remove_prefetched_objects()
db = router.db_for_write(self.model, instance=self.instance)
queryset = queryset.using(db)
if bulk:
# `QuerySet.update()` is intrinsically atomic.
queryset.update(**{self.field.name: None})
else:
with transaction.atomic(using=db, savepoint=False):
for obj in queryset:
setattr(obj, self.field.name, None)
obj.save(update_fields=[self.field.name])
_clear.alters_data = True
def set(self, objs, *, bulk=True, clear=False):
# Force evaluation of `objs` in case it's a queryset whose value
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
if self.field.null:
db = router.db_for_write(self.model, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear(bulk=bulk)
self.add(*objs, bulk=bulk)
else:
old_objs = set(self.using(db).all())
new_objs = []
for obj in objs:
if obj in old_objs:
old_objs.remove(obj)
else:
new_objs.append(obj)
self.remove(*old_objs, bulk=bulk)
self.add(*new_objs, bulk=bulk)
else:
self.add(*objs, bulk=bulk)
set.alters_data = True
return RelatedManager
class ManyToManyDescriptor(ReverseManyToOneDescriptor):
"""
Accessor to the related objects manager on the forward and reverse sides of
a many-to-many relation.
In the example::
class Pizza(Model):
toppings = ManyToManyField(Topping, related_name='pizzas')
``Pizza.toppings`` and ``Topping.pizzas`` are ``ManyToManyDescriptor``
instances.
Most of the implementation is delegated to a dynamically defined manager
class built by ``create_forward_many_to_many_manager()`` defined below.
"""
def __init__(self, rel, reverse=False):
super().__init__(rel)
self.reverse = reverse
@property
def through(self):
# through is provided so that you have easy access to the through
# model (Book.authors.through) for inlines, etc. This is done as
# a property to ensure that the fully resolved value is returned.
return self.rel.through
@cached_property
def related_manager_cls(self):
related_model = self.rel.related_model if self.reverse else self.rel.model
return create_forward_many_to_many_manager(
related_model._default_manager.__class__,
self.rel,
reverse=self.reverse,
)
@cached_property
def related_manager_cache_key(self):
if self.reverse:
# Symmetrical M2Ms won't have an accessor name, but should never
# end up in the reverse branch anyway, as the related_name ends up
# being hidden, and no public manager is created.
return self.rel.get_cache_name()
else:
# For forward managers, defer to the field name.
return self.field.get_cache_name()
def _get_set_deprecation_msg_params(self):
return (
'%s side of a many-to-many set' % ('reverse' if self.reverse else 'forward'),
self.rel.get_accessor_name() if self.reverse else self.field.name,
)
def create_forward_many_to_many_manager(superclass, rel, reverse):
"""
Create a manager for the either side of a many-to-many relation.
This manager subclasses another manager, generally the default manager of
the related model, and adds behaviors specific to many-to-many relations.
"""
class ManyRelatedManager(superclass):
def __init__(self, instance=None):
super().__init__()
self.instance = instance
if not reverse:
self.model = rel.model
self.query_field_name = rel.field.related_query_name()
self.prefetch_cache_name = rel.field.name
self.source_field_name = rel.field.m2m_field_name()
self.target_field_name = rel.field.m2m_reverse_field_name()
self.symmetrical = rel.symmetrical
else:
self.model = rel.related_model
self.query_field_name = rel.field.name
self.prefetch_cache_name = rel.field.related_query_name()
self.source_field_name = rel.field.m2m_reverse_field_name()
self.target_field_name = rel.field.m2m_field_name()
self.symmetrical = False
self.through = rel.through
self.reverse = reverse
self.source_field = self.through._meta.get_field(self.source_field_name)
self.target_field = self.through._meta.get_field(self.target_field_name)
self.core_filters = {}
self.pk_field_names = {}
for lh_field, rh_field in self.source_field.related_fields:
core_filter_key = '%s__%s' % (self.query_field_name, rh_field.name)
self.core_filters[core_filter_key] = getattr(instance, rh_field.attname)
self.pk_field_names[lh_field.name] = rh_field.name
self.related_val = self.source_field.get_foreign_related_value(instance)
if None in self.related_val:
raise ValueError('"%r" needs to have a value for field "%s" before '
'this many-to-many relationship can be used.' %
(instance, self.pk_field_names[self.source_field_name]))
# Even if this relation is not to pk, we require still pk value.
# The wish is that the instance has been already saved to DB,
# although having a pk value isn't a guarantee of that.
if instance.pk is None:
raise ValueError("%r instance needs to have a primary key value before "
"a many-to-many relationship can be used." %
instance.__class__.__name__)
def __call__(self, *, manager):
manager = getattr(self.model, manager)
manager_class = create_forward_many_to_many_manager(manager.__class__, rel, reverse)
return manager_class(instance=self.instance)
do_not_call_in_templates = True
def _build_remove_filters(self, removed_vals):
filters = Q((self.source_field_name, self.related_val))
# No need to add a subquery condition if removed_vals is a QuerySet without
# filters.
removed_vals_filters = (not isinstance(removed_vals, QuerySet) or
removed_vals._has_filters())
if removed_vals_filters:
filters &= Q((f'{self.target_field_name}__in', removed_vals))
if self.symmetrical:
symmetrical_filters = Q((self.target_field_name, self.related_val))
if removed_vals_filters:
symmetrical_filters &= Q((f'{self.source_field_name}__in', removed_vals))
filters |= symmetrical_filters
return filters
def _apply_rel_filters(self, queryset):
"""
Filter the queryset for the instance this manager is bound to.
"""
queryset._add_hints(instance=self.instance)
if self._db:
queryset = queryset.using(self._db)
queryset._defer_next_filter = True
return queryset._next_is_sticky().filter(**self.core_filters)
def _remove_prefetched_objects(self):
try:
self.instance._prefetched_objects_cache.pop(self.prefetch_cache_name)
except (AttributeError, KeyError):
pass # nothing to clear from cache
def get_queryset(self):
try:
return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
except (AttributeError, KeyError):
queryset = super().get_queryset()
return self._apply_rel_filters(queryset)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = super().get_queryset()
queryset._add_hints(instance=instances[0])
queryset = queryset.using(queryset._db or self._db)
query = {'%s__in' % self.query_field_name: instances}
queryset = queryset._next_is_sticky().filter(**query)
# M2M: need to annotate the query in order to get the primary model
# that the secondary model was actually related to. We know that
# there will already be a join on the join table, so we can just add
# the select.
# For non-autocreated 'through' models, can't assume we are
# dealing with PK values.
fk = self.through._meta.get_field(self.source_field_name)
join_table = fk.model._meta.db_table
connection = connections[queryset.db]
qn = connection.ops.quote_name
queryset = queryset.extra(select={
'_prefetch_related_val_%s' % f.attname:
'%s.%s' % (qn(join_table), qn(f.column)) for f in fk.local_related_fields})
return (
queryset,
lambda result: tuple(
getattr(result, '_prefetch_related_val_%s' % f.attname)
for f in fk.local_related_fields
),
lambda inst: tuple(
f.get_db_prep_value(getattr(inst, f.attname), connection)
for f in fk.foreign_related_fields
),
False,
self.prefetch_cache_name,
False,
)
def add(self, *objs, through_defaults=None):
self._remove_prefetched_objects()
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
self._add_items(
self.source_field_name, self.target_field_name, *objs,
through_defaults=through_defaults,
)
# If this is a symmetrical m2m relation to self, add the mirror
# entry in the m2m table.
if self.symmetrical:
self._add_items(
self.target_field_name,
self.source_field_name,
*objs,
through_defaults=through_defaults,
)
add.alters_data = True
def remove(self, *objs):
self._remove_prefetched_objects()
self._remove_items(self.source_field_name, self.target_field_name, *objs)
remove.alters_data = True
def clear(self):
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
signals.m2m_changed.send(
sender=self.through, action="pre_clear",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=None, using=db,
)
self._remove_prefetched_objects()
filters = self._build_remove_filters(super().get_queryset().using(db))
self.through._default_manager.using(db).filter(filters).delete()
signals.m2m_changed.send(
sender=self.through, action="post_clear",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=None, using=db,
)
clear.alters_data = True
def set(self, objs, *, clear=False, through_defaults=None):
# Force evaluation of `objs` in case it's a queryset whose value
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear()
self.add(*objs, through_defaults=through_defaults)
else:
old_ids = set(self.using(db).values_list(self.target_field.target_field.attname, flat=True))
new_objs = []
for obj in objs:
fk_val = (
self.target_field.get_foreign_related_value(obj)[0]
if isinstance(obj, self.model)
else self.target_field.get_prep_value(obj)
)
if fk_val in old_ids:
old_ids.remove(fk_val)
else:
new_objs.append(obj)
self.remove(*old_ids)
self.add(*new_objs, through_defaults=through_defaults)
set.alters_data = True
def create(self, *, through_defaults=None, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
new_obj = super(ManyRelatedManager, self.db_manager(db)).create(**kwargs)
self.add(new_obj, through_defaults=through_defaults)
return new_obj
create.alters_data = True
def get_or_create(self, *, through_defaults=None, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
obj, created = super(ManyRelatedManager, self.db_manager(db)).get_or_create(**kwargs)
# We only need to add() if created because if we got an object back
# from get() then the relationship already exists.
if created:
self.add(obj, through_defaults=through_defaults)
return obj, created
get_or_create.alters_data = True
def update_or_create(self, *, through_defaults=None, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
obj, created = super(ManyRelatedManager, self.db_manager(db)).update_or_create(**kwargs)
# We only need to add() if created because if we got an object back
# from get() then the relationship already exists.
if created:
self.add(obj, through_defaults=through_defaults)
return obj, created
update_or_create.alters_data = True
def _get_target_ids(self, target_field_name, objs):
"""
Return the set of ids of `objs` that the target field references.
"""
from django.db.models import Model
target_ids = set()
target_field = self.through._meta.get_field(target_field_name)
for obj in objs:
if isinstance(obj, self.model):
if not router.allow_relation(obj, self.instance):
raise ValueError(
'Cannot add "%r": instance is on database "%s", '
'value is on database "%s"' %
(obj, self.instance._state.db, obj._state.db)
)
target_id = target_field.get_foreign_related_value(obj)[0]
if target_id is None:
raise ValueError(
'Cannot add "%r": the value for field "%s" is None' %
(obj, target_field_name)
)
target_ids.add(target_id)
elif isinstance(obj, Model):
raise TypeError(
"'%s' instance expected, got %r" %
(self.model._meta.object_name, obj)
)
else:
target_ids.add(target_field.get_prep_value(obj))
return target_ids
def _get_missing_target_ids(self, source_field_name, target_field_name, db, target_ids):
"""
Return the subset of ids of `objs` that aren't already assigned to
this relationship.
"""
vals = self.through._default_manager.using(db).values_list(
target_field_name, flat=True
).filter(**{
source_field_name: self.related_val[0],
'%s__in' % target_field_name: target_ids,
})
return target_ids.difference(vals)
def _get_add_plan(self, db, source_field_name):
"""
Return a boolean triple of the way the add should be performed.
The first element is whether or not bulk_create(ignore_conflicts)
can be used, the second whether or not signals must be sent, and
the third element is whether or not the immediate bulk insertion
with conflicts ignored can be performed.
"""
# Conflicts can be ignored when the intermediary model is
# auto-created as the only possible collision is on the
# (source_id, target_id) tuple. The same assertion doesn't hold for
# user-defined intermediary models as they could have other fields
# causing conflicts which must be surfaced.
can_ignore_conflicts = (
self.through._meta.auto_created is not False and
connections[db].features.supports_ignore_conflicts
)
# Don't send the signal when inserting duplicate data row
# for symmetrical reverse entries.
must_send_signals = (self.reverse or source_field_name == self.source_field_name) and (
signals.m2m_changed.has_listeners(self.through)
)
# Fast addition through bulk insertion can only be performed
# if no m2m_changed listeners are connected for self.through
# as they require the added set of ids to be provided via
# pk_set.
return can_ignore_conflicts, must_send_signals, (can_ignore_conflicts and not must_send_signals)
def _add_items(self, source_field_name, target_field_name, *objs, through_defaults=None):
# source_field_name: the PK fieldname in join table for the source object
# target_field_name: the PK fieldname in join table for the target object
# *objs - objects to add. Either object instances, or primary keys of object instances.
if not objs:
return
through_defaults = dict(resolve_callables(through_defaults or {}))
target_ids = self._get_target_ids(target_field_name, objs)
db = router.db_for_write(self.through, instance=self.instance)
can_ignore_conflicts, must_send_signals, can_fast_add = self._get_add_plan(db, source_field_name)
if can_fast_add:
self.through._default_manager.using(db).bulk_create([
self.through(**{
'%s_id' % source_field_name: self.related_val[0],
'%s_id' % target_field_name: target_id,
})
for target_id in target_ids
], ignore_conflicts=True)
return
missing_target_ids = self._get_missing_target_ids(
source_field_name, target_field_name, db, target_ids
)
with transaction.atomic(using=db, savepoint=False):
if must_send_signals:
signals.m2m_changed.send(
sender=self.through, action='pre_add',
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=missing_target_ids, using=db,
)
# Add the ones that aren't there already.
self.through._default_manager.using(db).bulk_create([
self.through(**through_defaults, **{
'%s_id' % source_field_name: self.related_val[0],
'%s_id' % target_field_name: target_id,
})
for target_id in missing_target_ids
], ignore_conflicts=can_ignore_conflicts)
if must_send_signals:
signals.m2m_changed.send(
sender=self.through, action='post_add',
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=missing_target_ids, using=db,
)
def _remove_items(self, source_field_name, target_field_name, *objs):
# source_field_name: the PK colname in join table for the source object
# target_field_name: the PK colname in join table for the target object
# *objs - objects to remove. Either object instances, or primary
# keys of object instances.
if not objs:
return
# Check that all the objects are of the right type
old_ids = set()
for obj in objs:
if isinstance(obj, self.model):
fk_val = self.target_field.get_foreign_related_value(obj)[0]
old_ids.add(fk_val)
else:
old_ids.add(obj)
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
# Send a signal to the other end if need be.
signals.m2m_changed.send(
sender=self.through, action="pre_remove",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=old_ids, using=db,
)
target_model_qs = super().get_queryset()
if target_model_qs._has_filters():
old_vals = target_model_qs.using(db).filter(**{
'%s__in' % self.target_field.target_field.attname: old_ids})
else:
old_vals = old_ids
filters = self._build_remove_filters(old_vals)
self.through._default_manager.using(db).filter(filters).delete()
signals.m2m_changed.send(
sender=self.through, action="post_remove",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=old_ids, using=db,
)
return ManyRelatedManager
|
1b8271089954e7b17027babaff137dcd4d179cf5f78d891e72e9bc0fe0ba453b | """
"Rel objects" for related fields.
"Rel objects" (for lack of a better name) carry information about the relation
modeled by a related field and provide some utility functions. They're stored
in the ``remote_field`` attribute of the field.
They also act as reverse fields for the purposes of the Meta API because
they're the closest concept currently available.
"""
from django.core import exceptions
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
from . import BLANK_CHOICE_DASH
from .mixins import FieldCacheMixin
class ForeignObjectRel(FieldCacheMixin):
"""
Used by ForeignObject to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
# Field flags
auto_created = True
concrete = False
editable = False
is_relation = True
# Reverse relations are always nullable (Django can't enforce that a
# foreign key on the related model points to this model).
null = True
empty_strings_allowed = False
def __init__(self, field, to, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, on_delete=None):
self.field = field
self.model = to
self.related_name = related_name
self.related_query_name = related_query_name
self.limit_choices_to = {} if limit_choices_to is None else limit_choices_to
self.parent_link = parent_link
self.on_delete = on_delete
self.symmetrical = False
self.multiple = True
# Some of the following cached_properties can't be initialized in
# __init__ as the field doesn't have its model yet. Calling these methods
# before field.contribute_to_class() has been called will result in
# AttributeError
@cached_property
def hidden(self):
return self.is_hidden()
@cached_property
def name(self):
return self.field.related_query_name()
@property
def remote_field(self):
return self.field
@property
def target_field(self):
"""
When filtering against this relation, return the field on the remote
model against which the filtering should happen.
"""
target_fields = self.path_infos[-1].target_fields
if len(target_fields) > 1:
raise exceptions.FieldError("Can't use target_field for multicolumn relations.")
return target_fields[0]
@cached_property
def related_model(self):
if not self.field.model:
raise AttributeError(
"This property can't be accessed before self.field.contribute_to_class has been called.")
return self.field.model
@cached_property
def many_to_many(self):
return self.field.many_to_many
@cached_property
def many_to_one(self):
return self.field.one_to_many
@cached_property
def one_to_many(self):
return self.field.many_to_one
@cached_property
def one_to_one(self):
return self.field.one_to_one
def get_lookup(self, lookup_name):
return self.field.get_lookup(lookup_name)
def get_internal_type(self):
return self.field.get_internal_type()
@property
def db_type(self):
return self.field.db_type
def __repr__(self):
return '<%s: %s.%s>' % (
type(self).__name__,
self.related_model._meta.app_label,
self.related_model._meta.model_name,
)
@property
def identity(self):
return (
self.field,
self.model,
self.related_name,
self.related_query_name,
make_hashable(self.limit_choices_to),
self.parent_link,
self.on_delete,
self.symmetrical,
self.multiple,
)
def __eq__(self, other):
if not isinstance(other, self.__class__):
return NotImplemented
return self.identity == other.identity
def __hash__(self):
return hash(self.identity)
def __getstate__(self):
state = self.__dict__.copy()
# Delete the path_infos cached property because it can be recalculated
# at first invocation after deserialization. The attribute must be
# removed because subclasses like ManyToOneRel may have a PathInfo
# which contains an intermediate M2M table that's been dynamically
# created and doesn't exist in the .models module.
# This is a reverse relation, so there is no reverse_path_infos to
# delete.
state.pop('path_infos', None)
return state
def get_choices(
self, include_blank=True, blank_choice=BLANK_CHOICE_DASH,
limit_choices_to=None, ordering=(),
):
"""
Return choices with a default blank choices included, for use
as <select> choices for this field.
Analog of django.db.models.fields.Field.get_choices(), provided
initially for utilization by RelatedFieldListFilter.
"""
limit_choices_to = limit_choices_to or self.limit_choices_to
qs = self.related_model._default_manager.complex_filter(limit_choices_to)
if ordering:
qs = qs.order_by(*ordering)
return (blank_choice if include_blank else []) + [
(x.pk, str(x)) for x in qs
]
def is_hidden(self):
"""Should the related object be hidden?"""
return bool(self.related_name) and self.related_name[-1] == '+'
def get_joining_columns(self):
return self.field.get_reverse_joining_columns()
def get_extra_restriction(self, alias, related_alias):
return self.field.get_extra_restriction(related_alias, alias)
def set_field_name(self):
"""
Set the related field's name, this is not available until later stages
of app loading, so set_field_name is called from
set_attributes_from_rel()
"""
# By default foreign object doesn't relate to any remote field (for
# example custom multicolumn joins currently have no remote field).
self.field_name = None
def get_accessor_name(self, model=None):
# This method encapsulates the logic that decides what name to give an
# accessor descriptor that retrieves related many-to-one or
# many-to-many objects. It uses the lowercased object_name + "_set",
# but this can be overridden with the "related_name" option. Due to
# backwards compatibility ModelForms need to be able to provide an
# alternate model. See BaseInlineFormSet.get_default_prefix().
opts = model._meta if model else self.related_model._meta
model = model or self.related_model
if self.multiple:
# If this is a symmetrical m2m relation on self, there is no reverse accessor.
if self.symmetrical and model == self.model:
return None
if self.related_name:
return self.related_name
return opts.model_name + ('_set' if self.multiple else '')
def get_path_info(self, filtered_relation=None):
if filtered_relation:
return self.field.get_reverse_path_info(filtered_relation)
else:
return self.field.reverse_path_infos
@cached_property
def path_infos(self):
return self.get_path_info()
def get_cache_name(self):
"""
Return the name of the cache key to use for storing an instance of the
forward model on the reverse model.
"""
return self.get_accessor_name()
class ManyToOneRel(ForeignObjectRel):
"""
Used by the ForeignKey field to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
Note: Because we somewhat abuse the Rel objects by using them as reverse
fields we get the funny situation where
``ManyToOneRel.many_to_one == False`` and
``ManyToOneRel.one_to_many == True``. This is unfortunate but the actual
ManyToOneRel class is a private API and there is work underway to turn
reverse relations into actual fields.
"""
def __init__(self, field, to, field_name, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, on_delete=None):
super().__init__(
field, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
self.field_name = field_name
def __getstate__(self):
state = super().__getstate__()
state.pop('related_model', None)
return state
@property
def identity(self):
return super().identity + (self.field_name,)
def get_related_field(self):
"""
Return the Field in the 'to' object to which this relationship is tied.
"""
field = self.model._meta.get_field(self.field_name)
if not field.concrete:
raise exceptions.FieldDoesNotExist("No related field named '%s'" % self.field_name)
return field
def set_field_name(self):
self.field_name = self.field_name or self.model._meta.pk.name
class OneToOneRel(ManyToOneRel):
"""
Used by OneToOneField to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
def __init__(self, field, to, field_name, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, on_delete=None):
super().__init__(
field, to, field_name,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
self.multiple = False
class ManyToManyRel(ForeignObjectRel):
"""
Used by ManyToManyField to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
def __init__(self, field, to, related_name=None, related_query_name=None,
limit_choices_to=None, symmetrical=True, through=None,
through_fields=None, db_constraint=True):
super().__init__(
field, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
)
if through and not db_constraint:
raise ValueError("Can't supply a through model and db_constraint=False")
self.through = through
if through_fields and not through:
raise ValueError("Cannot specify through_fields without a through model")
self.through_fields = through_fields
self.symmetrical = symmetrical
self.db_constraint = db_constraint
@property
def identity(self):
return super().identity + (
self.through,
make_hashable(self.through_fields),
self.db_constraint,
)
def get_related_field(self):
"""
Return the field in the 'to' object to which this relationship is tied.
Provided for symmetry with ManyToOneRel.
"""
opts = self.through._meta
if self.through_fields:
field = opts.get_field(self.through_fields[0])
else:
for field in opts.fields:
rel = getattr(field, 'remote_field', None)
if rel and rel.model == self.model:
break
return field.foreign_related_fields[0]
|
a901a4db9d5853ea8e0f028e00945e1605d119ae24ea5ccfce4451ac9950d88c | """Database functions that do comparisons or type conversions."""
from django.db import NotSupportedError
from django.db.models.expressions import Func, Value
from django.db.models.fields.json import JSONField
from django.utils.regex_helper import _lazy_re_compile
class Cast(Func):
"""Coerce an expression to a new field type."""
function = 'CAST'
template = '%(function)s(%(expressions)s AS %(db_type)s)'
def __init__(self, expression, output_field):
super().__init__(expression, output_field=output_field)
def as_sql(self, compiler, connection, **extra_context):
extra_context['db_type'] = self.output_field.cast_db_type(connection)
return super().as_sql(compiler, connection, **extra_context)
def as_sqlite(self, compiler, connection, **extra_context):
db_type = self.output_field.db_type(connection)
if db_type in {'datetime', 'time'}:
# Use strftime as datetime/time don't keep fractional seconds.
template = 'strftime(%%s, %(expressions)s)'
sql, params = super().as_sql(compiler, connection, template=template, **extra_context)
format_string = '%H:%M:%f' if db_type == 'time' else '%Y-%m-%d %H:%M:%f'
params.insert(0, format_string)
return sql, params
elif db_type == 'date':
template = 'date(%(expressions)s)'
return super().as_sql(compiler, connection, template=template, **extra_context)
return self.as_sql(compiler, connection, **extra_context)
def as_mysql(self, compiler, connection, **extra_context):
template = None
output_type = self.output_field.get_internal_type()
# MySQL doesn't support explicit cast to float.
if output_type == 'FloatField':
template = '(%(expressions)s + 0.0)'
# MariaDB doesn't support explicit cast to JSON.
elif output_type == 'JSONField' and connection.mysql_is_mariadb:
template = "JSON_EXTRACT(%(expressions)s, '$')"
return self.as_sql(compiler, connection, template=template, **extra_context)
def as_postgresql(self, compiler, connection, **extra_context):
# CAST would be valid too, but the :: shortcut syntax is more readable.
# 'expressions' is wrapped in parentheses in case it's a complex
# expression.
return self.as_sql(compiler, connection, template='(%(expressions)s)::%(db_type)s', **extra_context)
def as_oracle(self, compiler, connection, **extra_context):
if self.output_field.get_internal_type() == 'JSONField':
# Oracle doesn't support explicit cast to JSON.
template = "JSON_QUERY(%(expressions)s, '$')"
return super().as_sql(compiler, connection, template=template, **extra_context)
return self.as_sql(compiler, connection, **extra_context)
class Coalesce(Func):
"""Return, from left to right, the first non-null expression."""
function = 'COALESCE'
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Coalesce must take at least two expressions')
super().__init__(*expressions, **extra)
@property
def empty_result_set_value(self):
for expression in self.get_source_expressions():
result = expression.empty_result_set_value
if result is NotImplemented or result is not None:
return result
return None
def as_oracle(self, compiler, connection, **extra_context):
# Oracle prohibits mixing TextField (NCLOB) and CharField (NVARCHAR2),
# so convert all fields to NCLOB when that type is expected.
if self.output_field.get_internal_type() == 'TextField':
clone = self.copy()
clone.set_source_expressions([
Func(expression, function='TO_NCLOB') for expression in self.get_source_expressions()
])
return super(Coalesce, clone).as_sql(compiler, connection, **extra_context)
return self.as_sql(compiler, connection, **extra_context)
class Collate(Func):
function = 'COLLATE'
template = '%(expressions)s %(function)s %(collation)s'
# Inspired from https://www.postgresql.org/docs/current/sql-syntax-lexical.html#SQL-SYNTAX-IDENTIFIERS
collation_re = _lazy_re_compile(r'^[\w\-]+$')
def __init__(self, expression, collation):
if not (collation and self.collation_re.match(collation)):
raise ValueError('Invalid collation name: %r.' % collation)
self.collation = collation
super().__init__(expression)
def as_sql(self, compiler, connection, **extra_context):
extra_context.setdefault('collation', connection.ops.quote_name(self.collation))
return super().as_sql(compiler, connection, **extra_context)
class Greatest(Func):
"""
Return the maximum expression.
If any expression is null the return value is database-specific:
On PostgreSQL, the maximum not-null expression is returned.
On MySQL, Oracle, and SQLite, if any expression is null, null is returned.
"""
function = 'GREATEST'
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Greatest must take at least two expressions')
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
"""Use the MAX function on SQLite."""
return super().as_sqlite(compiler, connection, function='MAX', **extra_context)
class JSONObject(Func):
function = 'JSON_OBJECT'
output_field = JSONField()
def __init__(self, **fields):
expressions = []
for key, value in fields.items():
expressions.extend((Value(key), value))
super().__init__(*expressions)
def as_sql(self, compiler, connection, **extra_context):
if not connection.features.has_json_object_function:
raise NotSupportedError(
'JSONObject() is not supported on this database backend.'
)
return super().as_sql(compiler, connection, **extra_context)
def as_postgresql(self, compiler, connection, **extra_context):
return self.as_sql(
compiler,
connection,
function='JSONB_BUILD_OBJECT',
**extra_context,
)
def as_oracle(self, compiler, connection, **extra_context):
class ArgJoiner:
def join(self, args):
args = [' VALUE '.join(arg) for arg in zip(args[::2], args[1::2])]
return ', '.join(args)
return self.as_sql(
compiler,
connection,
arg_joiner=ArgJoiner(),
template='%(function)s(%(expressions)s RETURNING CLOB)',
**extra_context,
)
class Least(Func):
"""
Return the minimum expression.
If any expression is null the return value is database-specific:
On PostgreSQL, return the minimum not-null expression.
On MySQL, Oracle, and SQLite, if any expression is null, return null.
"""
function = 'LEAST'
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Least must take at least two expressions')
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
"""Use the MIN function on SQLite."""
return super().as_sqlite(compiler, connection, function='MIN', **extra_context)
class NullIf(Func):
function = 'NULLIF'
arity = 2
def as_oracle(self, compiler, connection, **extra_context):
expression1 = self.get_source_expressions()[0]
if isinstance(expression1, Value) and expression1.value is None:
raise ValueError('Oracle does not allow Value(None) for expression1.')
return super().as_sql(compiler, connection, **extra_context)
|
8b8e019f527c539c0cfa28fb9699f3992b62febe87858a6d383f810abec1cce3 | from datetime import datetime
from django.conf import settings
from django.db.models.expressions import Func
from django.db.models.fields import (
DateField, DateTimeField, DurationField, Field, IntegerField, TimeField,
)
from django.db.models.lookups import (
Transform, YearExact, YearGt, YearGte, YearLt, YearLte,
)
from django.utils import timezone
class TimezoneMixin:
tzinfo = None
def get_tzname(self):
# Timezone conversions must happen to the input datetime *before*
# applying a function. 2015-12-31 23:00:00 -02:00 is stored in the
# database as 2016-01-01 01:00:00 +00:00. Any results should be
# based on the input datetime not the stored datetime.
tzname = None
if settings.USE_TZ:
if self.tzinfo is None:
tzname = timezone.get_current_timezone_name()
else:
tzname = timezone._get_timezone_name(self.tzinfo)
return tzname
class Extract(TimezoneMixin, Transform):
lookup_name = None
output_field = IntegerField()
def __init__(self, expression, lookup_name=None, tzinfo=None, **extra):
if self.lookup_name is None:
self.lookup_name = lookup_name
if self.lookup_name is None:
raise ValueError('lookup_name must be provided')
self.tzinfo = tzinfo
super().__init__(expression, **extra)
def as_sql(self, compiler, connection):
sql, params = compiler.compile(self.lhs)
lhs_output_field = self.lhs.output_field
if isinstance(lhs_output_field, DateTimeField):
tzname = self.get_tzname()
sql = connection.ops.datetime_extract_sql(self.lookup_name, sql, tzname)
elif self.tzinfo is not None:
raise ValueError('tzinfo can only be used with DateTimeField.')
elif isinstance(lhs_output_field, DateField):
sql = connection.ops.date_extract_sql(self.lookup_name, sql)
elif isinstance(lhs_output_field, TimeField):
sql = connection.ops.time_extract_sql(self.lookup_name, sql)
elif isinstance(lhs_output_field, DurationField):
if not connection.features.has_native_duration_field:
raise ValueError('Extract requires native DurationField database support.')
sql = connection.ops.time_extract_sql(self.lookup_name, sql)
else:
# resolve_expression has already validated the output_field so this
# assert should never be hit.
assert False, "Tried to Extract from an invalid type."
return sql, params
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
copy = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
field = getattr(copy.lhs, 'output_field', None)
if field is None:
return copy
if not isinstance(field, (DateField, DateTimeField, TimeField, DurationField)):
raise ValueError(
'Extract input expression must be DateField, DateTimeField, '
'TimeField, or DurationField.'
)
# Passing dates to functions expecting datetimes is most likely a mistake.
if type(field) == DateField and copy.lookup_name in ('hour', 'minute', 'second'):
raise ValueError(
"Cannot extract time component '%s' from DateField '%s'." % (copy.lookup_name, field.name)
)
if (
isinstance(field, DurationField) and
copy.lookup_name in ('year', 'iso_year', 'month', 'week', 'week_day', 'iso_week_day', 'quarter')
):
raise ValueError(
"Cannot extract component '%s' from DurationField '%s'."
% (copy.lookup_name, field.name)
)
return copy
class ExtractYear(Extract):
lookup_name = 'year'
class ExtractIsoYear(Extract):
"""Return the ISO-8601 week-numbering year."""
lookup_name = 'iso_year'
class ExtractMonth(Extract):
lookup_name = 'month'
class ExtractDay(Extract):
lookup_name = 'day'
class ExtractWeek(Extract):
"""
Return 1-52 or 53, based on ISO-8601, i.e., Monday is the first of the
week.
"""
lookup_name = 'week'
class ExtractWeekDay(Extract):
"""
Return Sunday=1 through Saturday=7.
To replicate this in Python: (mydatetime.isoweekday() % 7) + 1
"""
lookup_name = 'week_day'
class ExtractIsoWeekDay(Extract):
"""Return Monday=1 through Sunday=7, based on ISO-8601."""
lookup_name = 'iso_week_day'
class ExtractQuarter(Extract):
lookup_name = 'quarter'
class ExtractHour(Extract):
lookup_name = 'hour'
class ExtractMinute(Extract):
lookup_name = 'minute'
class ExtractSecond(Extract):
lookup_name = 'second'
DateField.register_lookup(ExtractYear)
DateField.register_lookup(ExtractMonth)
DateField.register_lookup(ExtractDay)
DateField.register_lookup(ExtractWeekDay)
DateField.register_lookup(ExtractIsoWeekDay)
DateField.register_lookup(ExtractWeek)
DateField.register_lookup(ExtractIsoYear)
DateField.register_lookup(ExtractQuarter)
TimeField.register_lookup(ExtractHour)
TimeField.register_lookup(ExtractMinute)
TimeField.register_lookup(ExtractSecond)
DateTimeField.register_lookup(ExtractHour)
DateTimeField.register_lookup(ExtractMinute)
DateTimeField.register_lookup(ExtractSecond)
ExtractYear.register_lookup(YearExact)
ExtractYear.register_lookup(YearGt)
ExtractYear.register_lookup(YearGte)
ExtractYear.register_lookup(YearLt)
ExtractYear.register_lookup(YearLte)
ExtractIsoYear.register_lookup(YearExact)
ExtractIsoYear.register_lookup(YearGt)
ExtractIsoYear.register_lookup(YearGte)
ExtractIsoYear.register_lookup(YearLt)
ExtractIsoYear.register_lookup(YearLte)
class Now(Func):
template = 'CURRENT_TIMESTAMP'
output_field = DateTimeField()
def as_postgresql(self, compiler, connection, **extra_context):
# PostgreSQL's CURRENT_TIMESTAMP means "the time at the start of the
# transaction". Use STATEMENT_TIMESTAMP to be cross-compatible with
# other databases.
return self.as_sql(compiler, connection, template='STATEMENT_TIMESTAMP()', **extra_context)
class TruncBase(TimezoneMixin, Transform):
kind = None
tzinfo = None
# RemovedInDjango50Warning: when the deprecation ends, remove is_dst
# argument.
def __init__(self, expression, output_field=None, tzinfo=None, is_dst=timezone.NOT_PASSED, **extra):
self.tzinfo = tzinfo
self.is_dst = is_dst
super().__init__(expression, output_field=output_field, **extra)
def as_sql(self, compiler, connection):
inner_sql, inner_params = compiler.compile(self.lhs)
tzname = None
if isinstance(self.lhs.output_field, DateTimeField):
tzname = self.get_tzname()
elif self.tzinfo is not None:
raise ValueError('tzinfo can only be used with DateTimeField.')
if isinstance(self.output_field, DateTimeField):
sql = connection.ops.datetime_trunc_sql(self.kind, inner_sql, tzname)
elif isinstance(self.output_field, DateField):
sql = connection.ops.date_trunc_sql(self.kind, inner_sql, tzname)
elif isinstance(self.output_field, TimeField):
sql = connection.ops.time_trunc_sql(self.kind, inner_sql, tzname)
else:
raise ValueError('Trunc only valid on DateField, TimeField, or DateTimeField.')
return sql, inner_params
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
copy = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
field = copy.lhs.output_field
# DateTimeField is a subclass of DateField so this works for both.
if not isinstance(field, (DateField, TimeField)):
raise TypeError(
"%r isn't a DateField, TimeField, or DateTimeField." % field.name
)
# If self.output_field was None, then accessing the field will trigger
# the resolver to assign it to self.lhs.output_field.
if not isinstance(copy.output_field, (DateField, DateTimeField, TimeField)):
raise ValueError('output_field must be either DateField, TimeField, or DateTimeField')
# Passing dates or times to functions expecting datetimes is most
# likely a mistake.
class_output_field = self.__class__.output_field if isinstance(self.__class__.output_field, Field) else None
output_field = class_output_field or copy.output_field
has_explicit_output_field = class_output_field or field.__class__ is not copy.output_field.__class__
if type(field) == DateField and (
isinstance(output_field, DateTimeField) or copy.kind in ('hour', 'minute', 'second', 'time')):
raise ValueError("Cannot truncate DateField '%s' to %s." % (
field.name, output_field.__class__.__name__ if has_explicit_output_field else 'DateTimeField'
))
elif isinstance(field, TimeField) and (
isinstance(output_field, DateTimeField) or
copy.kind in ('year', 'quarter', 'month', 'week', 'day', 'date')):
raise ValueError("Cannot truncate TimeField '%s' to %s." % (
field.name, output_field.__class__.__name__ if has_explicit_output_field else 'DateTimeField'
))
return copy
def convert_value(self, value, expression, connection):
if isinstance(self.output_field, DateTimeField):
if not settings.USE_TZ:
pass
elif value is not None:
value = value.replace(tzinfo=None)
value = timezone.make_aware(value, self.tzinfo, is_dst=self.is_dst)
elif not connection.features.has_zoneinfo_database:
raise ValueError(
'Database returned an invalid datetime value. Are time '
'zone definitions for your database installed?'
)
elif isinstance(value, datetime):
if value is None:
pass
elif isinstance(self.output_field, DateField):
value = value.date()
elif isinstance(self.output_field, TimeField):
value = value.time()
return value
class Trunc(TruncBase):
# RemovedInDjango50Warning: when the deprecation ends, remove is_dst
# argument.
def __init__(self, expression, kind, output_field=None, tzinfo=None, is_dst=timezone.NOT_PASSED, **extra):
self.kind = kind
super().__init__(
expression, output_field=output_field, tzinfo=tzinfo,
is_dst=is_dst, **extra
)
class TruncYear(TruncBase):
kind = 'year'
class TruncQuarter(TruncBase):
kind = 'quarter'
class TruncMonth(TruncBase):
kind = 'month'
class TruncWeek(TruncBase):
"""Truncate to midnight on the Monday of the week."""
kind = 'week'
class TruncDay(TruncBase):
kind = 'day'
class TruncDate(TruncBase):
kind = 'date'
lookup_name = 'date'
output_field = DateField()
def as_sql(self, compiler, connection):
# Cast to date rather than truncate to date.
lhs, lhs_params = compiler.compile(self.lhs)
tzname = self.get_tzname()
sql = connection.ops.datetime_cast_date_sql(lhs, tzname)
return sql, lhs_params
class TruncTime(TruncBase):
kind = 'time'
lookup_name = 'time'
output_field = TimeField()
def as_sql(self, compiler, connection):
# Cast to time rather than truncate to time.
lhs, lhs_params = compiler.compile(self.lhs)
tzname = self.get_tzname()
sql = connection.ops.datetime_cast_time_sql(lhs, tzname)
return sql, lhs_params
class TruncHour(TruncBase):
kind = 'hour'
class TruncMinute(TruncBase):
kind = 'minute'
class TruncSecond(TruncBase):
kind = 'second'
DateTimeField.register_lookup(TruncDate)
DateTimeField.register_lookup(TruncTime)
|
6dc6d9dfc9a6ad65b28cf6ac435c7c5f281d0644c91b5cf32ec1ea18e3496c71 | """
Create SQL statements for QuerySets.
The code in here encapsulates all of the SQL construction so that QuerySets
themselves do not have to (and could be backed by things other than SQL
databases). The abstraction barrier only works one way: this module has to know
all about the internals of models in order to get the information it needs.
"""
import copy
import difflib
import functools
import sys
from collections import Counter, namedtuple
from collections.abc import Iterator, Mapping
from itertools import chain, count, product
from string import ascii_uppercase
from django.core.exceptions import FieldDoesNotExist, FieldError
from django.db import DEFAULT_DB_ALIAS, NotSupportedError, connections
from django.db.models.aggregates import Count
from django.db.models.constants import LOOKUP_SEP
from django.db.models.expressions import (
BaseExpression, Col, Exists, F, OuterRef, Ref, ResolvedOuterRef,
)
from django.db.models.fields import Field
from django.db.models.fields.related_lookups import MultiColSource
from django.db.models.lookups import Lookup
from django.db.models.query_utils import (
Q, check_rel_lookup_compatibility, refs_expression,
)
from django.db.models.sql.constants import INNER, LOUTER, ORDER_DIR, SINGLE
from django.db.models.sql.datastructures import (
BaseTable, Empty, Join, MultiJoin,
)
from django.db.models.sql.where import (
AND, OR, ExtraWhere, NothingNode, WhereNode,
)
from django.utils.functional import cached_property
from django.utils.tree import Node
__all__ = ['Query', 'RawQuery']
def get_field_names_from_opts(opts):
return set(chain.from_iterable(
(f.name, f.attname) if f.concrete else (f.name,)
for f in opts.get_fields()
))
def get_children_from_q(q):
for child in q.children:
if isinstance(child, Node):
yield from get_children_from_q(child)
else:
yield child
JoinInfo = namedtuple(
'JoinInfo',
('final_field', 'targets', 'opts', 'joins', 'path', 'transform_function')
)
class RawQuery:
"""A single raw SQL query."""
def __init__(self, sql, using, params=()):
self.params = params
self.sql = sql
self.using = using
self.cursor = None
# Mirror some properties of a normal query so that
# the compiler can be used to process results.
self.low_mark, self.high_mark = 0, None # Used for offset/limit
self.extra_select = {}
self.annotation_select = {}
def chain(self, using):
return self.clone(using)
def clone(self, using):
return RawQuery(self.sql, using, params=self.params)
def get_columns(self):
if self.cursor is None:
self._execute_query()
converter = connections[self.using].introspection.identifier_converter
return [converter(column_meta[0])
for column_meta in self.cursor.description]
def __iter__(self):
# Always execute a new query for a new iterator.
# This could be optimized with a cache at the expense of RAM.
self._execute_query()
if not connections[self.using].features.can_use_chunked_reads:
# If the database can't use chunked reads we need to make sure we
# evaluate the entire query up front.
result = list(self.cursor)
else:
result = self.cursor
return iter(result)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
@property
def params_type(self):
if self.params is None:
return None
return dict if isinstance(self.params, Mapping) else tuple
def __str__(self):
if self.params_type is None:
return self.sql
return self.sql % self.params_type(self.params)
def _execute_query(self):
connection = connections[self.using]
# Adapt parameters to the database, as much as possible considering
# that the target type isn't known. See #17755.
params_type = self.params_type
adapter = connection.ops.adapt_unknown_value
if params_type is tuple:
params = tuple(adapter(val) for val in self.params)
elif params_type is dict:
params = {key: adapter(val) for key, val in self.params.items()}
elif params_type is None:
params = None
else:
raise RuntimeError("Unexpected params type: %s" % params_type)
self.cursor = connection.cursor()
self.cursor.execute(self.sql, params)
ExplainInfo = namedtuple('ExplainInfo', ('format', 'options'))
class Query(BaseExpression):
"""A single SQL query."""
alias_prefix = 'T'
empty_result_set_value = None
subq_aliases = frozenset([alias_prefix])
compiler = 'SQLCompiler'
base_table_class = BaseTable
join_class = Join
def __init__(self, model, alias_cols=True):
self.model = model
self.alias_refcount = {}
# alias_map is the most important data structure regarding joins.
# It's used for recording which joins exist in the query and what
# types they are. The key is the alias of the joined table (possibly
# the table name) and the value is a Join-like object (see
# sql.datastructures.Join for more information).
self.alias_map = {}
# Whether to provide alias to columns during reference resolving.
self.alias_cols = alias_cols
# Sometimes the query contains references to aliases in outer queries (as
# a result of split_exclude). Correct alias quoting needs to know these
# aliases too.
# Map external tables to whether they are aliased.
self.external_aliases = {}
self.table_map = {} # Maps table names to list of aliases.
self.default_cols = True
self.default_ordering = True
self.standard_ordering = True
self.used_aliases = set()
self.filter_is_sticky = False
self.subquery = False
# SQL-related attributes
# Select and related select clauses are expressions to use in the
# SELECT clause of the query.
# The select is used for cases where we want to set up the select
# clause to contain other than default fields (values(), subqueries...)
# Note that annotations go to annotations dictionary.
self.select = ()
self.where = WhereNode()
# The group_by attribute can have one of the following forms:
# - None: no group by at all in the query
# - A tuple of expressions: group by (at least) those expressions.
# String refs are also allowed for now.
# - True: group by all select fields of the model
# See compiler.get_group_by() for details.
self.group_by = None
self.order_by = ()
self.low_mark, self.high_mark = 0, None # Used for offset/limit
self.distinct = False
self.distinct_fields = ()
self.select_for_update = False
self.select_for_update_nowait = False
self.select_for_update_skip_locked = False
self.select_for_update_of = ()
self.select_for_no_key_update = False
self.select_related = False
# Arbitrary limit for select_related to prevents infinite recursion.
self.max_depth = 5
# Holds the selects defined by a call to values() or values_list()
# excluding annotation_select and extra_select.
self.values_select = ()
# SQL annotation-related attributes
self.annotations = {} # Maps alias -> Annotation Expression
self.annotation_select_mask = None
self._annotation_select_cache = None
# Set combination attributes
self.combinator = None
self.combinator_all = False
self.combined_queries = ()
# These are for extensions. The contents are more or less appended
# verbatim to the appropriate clause.
self.extra = {} # Maps col_alias -> (col_sql, params).
self.extra_select_mask = None
self._extra_select_cache = None
self.extra_tables = ()
self.extra_order_by = ()
# A tuple that is a set of model field names and either True, if these
# are the fields to defer, or False if these are the only fields to
# load.
self.deferred_loading = (frozenset(), True)
self._filtered_relations = {}
self.explain_info = None
@property
def output_field(self):
if len(self.select) == 1:
select = self.select[0]
return getattr(select, 'target', None) or select.field
elif len(self.annotation_select) == 1:
return next(iter(self.annotation_select.values())).output_field
@property
def has_select_fields(self):
return bool(self.select or self.annotation_select_mask or self.extra_select_mask)
@cached_property
def base_table(self):
for alias in self.alias_map:
return alias
def __str__(self):
"""
Return the query as a string of SQL with the parameter values
substituted in (use sql_with_params() to see the unsubstituted string).
Parameter values won't necessarily be quoted correctly, since that is
done by the database interface at execution time.
"""
sql, params = self.sql_with_params()
return sql % params
def sql_with_params(self):
"""
Return the query as an SQL string and the parameters that will be
substituted into the query.
"""
return self.get_compiler(DEFAULT_DB_ALIAS).as_sql()
def __deepcopy__(self, memo):
"""Limit the amount of work when a Query is deepcopied."""
result = self.clone()
memo[id(self)] = result
return result
def get_compiler(self, using=None, connection=None, elide_empty=True):
if using is None and connection is None:
raise ValueError("Need either using or connection")
if using:
connection = connections[using]
return connection.ops.compiler(self.compiler)(self, connection, using, elide_empty)
def get_meta(self):
"""
Return the Options instance (the model._meta) from which to start
processing. Normally, this is self.model._meta, but it can be changed
by subclasses.
"""
return self.model._meta
def clone(self):
"""
Return a copy of the current Query. A lightweight alternative to
to deepcopy().
"""
obj = Empty()
obj.__class__ = self.__class__
# Copy references to everything.
obj.__dict__ = self.__dict__.copy()
# Clone attributes that can't use shallow copy.
obj.alias_refcount = self.alias_refcount.copy()
obj.alias_map = self.alias_map.copy()
obj.external_aliases = self.external_aliases.copy()
obj.table_map = self.table_map.copy()
obj.where = self.where.clone()
obj.annotations = self.annotations.copy()
if self.annotation_select_mask is not None:
obj.annotation_select_mask = self.annotation_select_mask.copy()
if self.combined_queries:
obj.combined_queries = tuple([
query.clone() for query in self.combined_queries
])
# _annotation_select_cache cannot be copied, as doing so breaks the
# (necessary) state in which both annotations and
# _annotation_select_cache point to the same underlying objects.
# It will get re-populated in the cloned queryset the next time it's
# used.
obj._annotation_select_cache = None
obj.extra = self.extra.copy()
if self.extra_select_mask is not None:
obj.extra_select_mask = self.extra_select_mask.copy()
if self._extra_select_cache is not None:
obj._extra_select_cache = self._extra_select_cache.copy()
if self.select_related is not False:
# Use deepcopy because select_related stores fields in nested
# dicts.
obj.select_related = copy.deepcopy(obj.select_related)
if 'subq_aliases' in self.__dict__:
obj.subq_aliases = self.subq_aliases.copy()
obj.used_aliases = self.used_aliases.copy()
obj._filtered_relations = self._filtered_relations.copy()
# Clear the cached_property
try:
del obj.base_table
except AttributeError:
pass
return obj
def chain(self, klass=None):
"""
Return a copy of the current Query that's ready for another operation.
The klass argument changes the type of the Query, e.g. UpdateQuery.
"""
obj = self.clone()
if klass and obj.__class__ != klass:
obj.__class__ = klass
if not obj.filter_is_sticky:
obj.used_aliases = set()
obj.filter_is_sticky = False
if hasattr(obj, '_setup_query'):
obj._setup_query()
return obj
def relabeled_clone(self, change_map):
clone = self.clone()
clone.change_aliases(change_map)
return clone
def _get_col(self, target, field, alias):
if not self.alias_cols:
alias = None
return target.get_col(alias, field)
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
# FIXME: These conditions are fairly arbitrary. Identify a better
# method of having expressions decide which code path they should
# take.
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, (WhereNode, Lookup)):
# Decompose the subexpressions further. The code here is
# copied from the else clause, but this condition must appear
# before the contains_aggregate/is_summary condition below.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
else:
# Reuse aliases of expressions already selected in subquery.
for col_alias, selected_annotation in self.annotation_select.items():
if selected_annotation is expr:
new_expr = Ref(col_alias, expr)
break
else:
# An expression that is not selected the subquery.
if isinstance(expr, Col) or (expr.contains_aggregate and not expr.is_summary):
# Reference column or another aggregate. Select it
# under a non-conflicting alias.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_expr = Ref(col_alias, expr)
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
def get_aggregation(self, using, added_aggregate_names):
"""
Return the dictionary with the values of the existing aggregations.
"""
if not self.annotation_select:
return {}
existing_annotations = [
annotation for alias, annotation
in self.annotations.items()
if alias not in added_aggregate_names
]
# Decide if we need to use a subquery.
#
# Existing annotations would cause incorrect results as get_aggregation()
# must produce just one result and thus must not use GROUP BY. But we
# aren't smart enough to remove the existing annotations from the
# query, so those would force us to use GROUP BY.
#
# If the query has limit or distinct, or uses set operations, then
# those operations must be done in a subquery so that the query
# aggregates on the limit and/or distinct results instead of applying
# the distinct and limit after the aggregation.
if (isinstance(self.group_by, tuple) or self.is_sliced or existing_annotations or
self.distinct or self.combinator):
from django.db.models.sql.subqueries import AggregateQuery
inner_query = self.clone()
inner_query.subquery = True
outer_query = AggregateQuery(self.model, inner_query)
inner_query.select_for_update = False
inner_query.select_related = False
inner_query.set_annotation_mask(self.annotation_select)
# Queries with distinct_fields need ordering and when a limit is
# applied we must take the slice from the ordered query. Otherwise
# no need for ordering.
inner_query.clear_ordering(force=False)
if not inner_query.distinct:
# If the inner query uses default select and it has some
# aggregate annotations, then we must make sure the inner
# query is grouped by the main model's primary key. However,
# clearing the select clause can alter results if distinct is
# used.
has_existing_aggregate_annotations = any(
annotation for annotation in existing_annotations
if getattr(annotation, 'contains_aggregate', True)
)
if inner_query.default_cols and has_existing_aggregate_annotations:
inner_query.group_by = (self.model._meta.pk.get_col(inner_query.get_initial_alias()),)
inner_query.default_cols = False
relabels = {t: 'subquery' for t in inner_query.alias_map}
relabels[None] = 'subquery'
# Remove any aggregates marked for reduction from the subquery
# and move them to the outer AggregateQuery.
col_cnt = 0
for alias, expression in list(inner_query.annotation_select.items()):
annotation_select_mask = inner_query.annotation_select_mask
if expression.is_summary:
expression, col_cnt = inner_query.rewrite_cols(expression, col_cnt)
outer_query.annotations[alias] = expression.relabeled_clone(relabels)
del inner_query.annotations[alias]
annotation_select_mask.remove(alias)
# Make sure the annotation_select wont use cached results.
inner_query.set_annotation_mask(inner_query.annotation_select_mask)
if inner_query.select == () and not inner_query.default_cols and not inner_query.annotation_select_mask:
# In case of Model.objects[0:3].count(), there would be no
# field selected in the inner query, yet we must use a subquery.
# So, make sure at least one field is selected.
inner_query.select = (self.model._meta.pk.get_col(inner_query.get_initial_alias()),)
else:
outer_query = self
self.select = ()
self.default_cols = False
self.extra = {}
empty_set_result = [
expression.empty_result_set_value
for expression in outer_query.annotation_select.values()
]
elide_empty = not any(result is NotImplemented for result in empty_set_result)
outer_query.clear_ordering(force=True)
outer_query.clear_limits()
outer_query.select_for_update = False
outer_query.select_related = False
compiler = outer_query.get_compiler(using, elide_empty=elide_empty)
result = compiler.execute_sql(SINGLE)
if result is None:
result = empty_set_result
converters = compiler.get_converters(outer_query.annotation_select.values())
result = next(compiler.apply_converters((result,), converters))
return dict(zip(outer_query.annotation_select, result))
def get_count(self, using):
"""
Perform a COUNT() query using the current filter constraints.
"""
obj = self.clone()
obj.add_annotation(Count('*'), alias='__count', is_summary=True)
return obj.get_aggregation(using, ['__count'])['__count']
def has_filters(self):
return self.where
def exists(self, using, limit=True):
q = self.clone()
if not q.distinct:
if q.group_by is True:
q.add_fields((f.attname for f in self.model._meta.concrete_fields), False)
# Disable GROUP BY aliases to avoid orphaning references to the
# SELECT clause which is about to be cleared.
q.set_group_by(allow_aliases=False)
q.clear_select_clause()
if q.combined_queries and q.combinator == 'union':
limit_combined = connections[using].features.supports_slicing_ordering_in_compound
q.combined_queries = tuple(
combined_query.exists(using, limit=limit_combined)
for combined_query in q.combined_queries
)
q.clear_ordering(force=True)
if limit:
q.set_limits(high=1)
q.add_extra({'a': 1}, None, None, None, None, None)
q.set_extra_mask(['a'])
return q
def has_results(self, using):
q = self.exists(using)
compiler = q.get_compiler(using=using)
return compiler.has_results()
def explain(self, using, format=None, **options):
q = self.clone()
q.explain_info = ExplainInfo(format, options)
compiler = q.get_compiler(using=using)
return '\n'.join(compiler.explain_query())
def combine(self, rhs, connector):
"""
Merge the 'rhs' query into the current one (with any 'rhs' effects
being applied *after* (that is, "to the right of") anything in the
current query. 'rhs' is not modified during a call to this function.
The 'connector' parameter describes how to connect filters from the
'rhs' query.
"""
if self.model != rhs.model:
raise TypeError('Cannot combine queries on two different base models.')
if self.is_sliced:
raise TypeError('Cannot combine queries once a slice has been taken.')
if self.distinct != rhs.distinct:
raise TypeError('Cannot combine a unique query with a non-unique query.')
if self.distinct_fields != rhs.distinct_fields:
raise TypeError('Cannot combine queries with different distinct fields.')
# If lhs and rhs shares the same alias prefix, it is possible to have
# conflicting alias changes like T4 -> T5, T5 -> T6, which might end up
# as T4 -> T6 while combining two querysets. To prevent this, change an
# alias prefix of the rhs and update current aliases accordingly,
# except if the alias is the base table since it must be present in the
# query on both sides.
initial_alias = self.get_initial_alias()
rhs.bump_prefix(self, exclude={initial_alias})
# Work out how to relabel the rhs aliases, if necessary.
change_map = {}
conjunction = (connector == AND)
# Determine which existing joins can be reused. When combining the
# query with AND we must recreate all joins for m2m filters. When
# combining with OR we can reuse joins. The reason is that in AND
# case a single row can't fulfill a condition like:
# revrel__col=1 & revrel__col=2
# But, there might be two different related rows matching this
# condition. In OR case a single True is enough, so single row is
# enough, too.
#
# Note that we will be creating duplicate joins for non-m2m joins in
# the AND case. The results will be correct but this creates too many
# joins. This is something that could be fixed later on.
reuse = set() if conjunction else set(self.alias_map)
joinpromoter = JoinPromoter(connector, 2, False)
joinpromoter.add_votes(
j for j in self.alias_map if self.alias_map[j].join_type == INNER)
rhs_votes = set()
# Now, add the joins from rhs query into the new query (skipping base
# table).
rhs_tables = list(rhs.alias_map)[1:]
for alias in rhs_tables:
join = rhs.alias_map[alias]
# If the left side of the join was already relabeled, use the
# updated alias.
join = join.relabeled_clone(change_map)
new_alias = self.join(join, reuse=reuse)
if join.join_type == INNER:
rhs_votes.add(new_alias)
# We can't reuse the same join again in the query. If we have two
# distinct joins for the same connection in rhs query, then the
# combined query must have two joins, too.
reuse.discard(new_alias)
if alias != new_alias:
change_map[alias] = new_alias
if not rhs.alias_refcount[alias]:
# The alias was unused in the rhs query. Unref it so that it
# will be unused in the new query, too. We have to add and
# unref the alias so that join promotion has information of
# the join type for the unused alias.
self.unref_alias(new_alias)
joinpromoter.add_votes(rhs_votes)
joinpromoter.update_join_types(self)
# Combine subqueries aliases to ensure aliases relabelling properly
# handle subqueries when combining where and select clauses.
self.subq_aliases |= rhs.subq_aliases
# Now relabel a copy of the rhs where-clause and add it to the current
# one.
w = rhs.where.clone()
w.relabel_aliases(change_map)
self.where.add(w, connector)
# Selection columns and extra extensions are those provided by 'rhs'.
if rhs.select:
self.set_select([col.relabeled_clone(change_map) for col in rhs.select])
else:
self.select = ()
if connector == OR:
# It would be nice to be able to handle this, but the queries don't
# really make sense (or return consistent value sets). Not worth
# the extra complexity when you can write a real query instead.
if self.extra and rhs.extra:
raise ValueError("When merging querysets using 'or', you cannot have extra(select=...) on both sides.")
self.extra.update(rhs.extra)
extra_select_mask = set()
if self.extra_select_mask is not None:
extra_select_mask.update(self.extra_select_mask)
if rhs.extra_select_mask is not None:
extra_select_mask.update(rhs.extra_select_mask)
if extra_select_mask:
self.set_extra_mask(extra_select_mask)
self.extra_tables += rhs.extra_tables
# Ordering uses the 'rhs' ordering, unless it has none, in which case
# the current ordering is used.
self.order_by = rhs.order_by or self.order_by
self.extra_order_by = rhs.extra_order_by or self.extra_order_by
def deferred_to_data(self, target, callback):
"""
Convert the self.deferred_loading data structure to an alternate data
structure, describing the field that *will* be loaded. This is used to
compute the columns to select from the database and also by the
QuerySet class to work out which fields are being initialized on each
model. Models that have all their fields included aren't mentioned in
the result, only those that have field restrictions in place.
The "target" parameter is the instance that is populated (in place).
The "callback" is a function that is called whenever a (model, field)
pair need to be added to "target". It accepts three parameters:
"target", and the model and list of fields being added for that model.
"""
field_names, defer = self.deferred_loading
if not field_names:
return
orig_opts = self.get_meta()
seen = {}
must_include = {orig_opts.concrete_model: {orig_opts.pk}}
for field_name in field_names:
parts = field_name.split(LOOKUP_SEP)
cur_model = self.model._meta.concrete_model
opts = orig_opts
for name in parts[:-1]:
old_model = cur_model
if name in self._filtered_relations:
name = self._filtered_relations[name].relation_name
source = opts.get_field(name)
if is_reverse_o2o(source):
cur_model = source.related_model
else:
cur_model = source.remote_field.model
opts = cur_model._meta
# Even if we're "just passing through" this model, we must add
# both the current model's pk and the related reference field
# (if it's not a reverse relation) to the things we select.
if not is_reverse_o2o(source):
must_include[old_model].add(source)
add_to_dict(must_include, cur_model, opts.pk)
field = opts.get_field(parts[-1])
is_reverse_object = field.auto_created and not field.concrete
model = field.related_model if is_reverse_object else field.model
model = model._meta.concrete_model
if model == opts.model:
model = cur_model
if not is_reverse_o2o(field):
add_to_dict(seen, model, field)
if defer:
# We need to load all fields for each model, except those that
# appear in "seen" (for all models that appear in "seen"). The only
# slight complexity here is handling fields that exist on parent
# models.
workset = {}
for model, values in seen.items():
for field in model._meta.local_fields:
if field not in values:
m = field.model._meta.concrete_model
add_to_dict(workset, m, field)
for model, values in must_include.items():
# If we haven't included a model in workset, we don't add the
# corresponding must_include fields for that model, since an
# empty set means "include all fields". That's why there's no
# "else" branch here.
if model in workset:
workset[model].update(values)
for model, values in workset.items():
callback(target, model, values)
else:
for model, values in must_include.items():
if model in seen:
seen[model].update(values)
else:
# As we've passed through this model, but not explicitly
# included any fields, we have to make sure it's mentioned
# so that only the "must include" fields are pulled in.
seen[model] = values
# Now ensure that every model in the inheritance chain is mentioned
# in the parent list. Again, it must be mentioned to ensure that
# only "must include" fields are pulled in.
for model in orig_opts.get_parent_list():
seen.setdefault(model, set())
for model, values in seen.items():
callback(target, model, values)
def table_alias(self, table_name, create=False, filtered_relation=None):
"""
Return a table alias for the given table_name and whether this is a
new alias or not.
If 'create' is true, a new alias is always created. Otherwise, the
most recently created alias for the table (if one exists) is reused.
"""
alias_list = self.table_map.get(table_name)
if not create and alias_list:
alias = alias_list[0]
self.alias_refcount[alias] += 1
return alias, False
# Create a new alias for this table.
if alias_list:
alias = '%s%d' % (self.alias_prefix, len(self.alias_map) + 1)
alias_list.append(alias)
else:
# The first occurrence of a table uses the table name directly.
alias = filtered_relation.alias if filtered_relation is not None else table_name
self.table_map[table_name] = [alias]
self.alias_refcount[alias] = 1
return alias, True
def ref_alias(self, alias):
"""Increases the reference count for this alias."""
self.alias_refcount[alias] += 1
def unref_alias(self, alias, amount=1):
"""Decreases the reference count for this alias."""
self.alias_refcount[alias] -= amount
def promote_joins(self, aliases):
"""
Promote recursively the join type of given aliases and its children to
an outer join. If 'unconditional' is False, only promote the join if
it is nullable or the parent join is an outer join.
The children promotion is done to avoid join chains that contain a LOUTER
b INNER c. So, if we have currently a INNER b INNER c and a->b is promoted,
then we must also promote b->c automatically, or otherwise the promotion
of a->b doesn't actually change anything in the query results.
"""
aliases = list(aliases)
while aliases:
alias = aliases.pop(0)
if self.alias_map[alias].join_type is None:
# This is the base table (first FROM entry) - this table
# isn't really joined at all in the query, so we should not
# alter its join type.
continue
# Only the first alias (skipped above) should have None join_type
assert self.alias_map[alias].join_type is not None
parent_alias = self.alias_map[alias].parent_alias
parent_louter = parent_alias and self.alias_map[parent_alias].join_type == LOUTER
already_louter = self.alias_map[alias].join_type == LOUTER
if ((self.alias_map[alias].nullable or parent_louter) and
not already_louter):
self.alias_map[alias] = self.alias_map[alias].promote()
# Join type of 'alias' changed, so re-examine all aliases that
# refer to this one.
aliases.extend(
join for join in self.alias_map
if self.alias_map[join].parent_alias == alias and join not in aliases
)
def demote_joins(self, aliases):
"""
Change join type from LOUTER to INNER for all joins in aliases.
Similarly to promote_joins(), this method must ensure no join chains
containing first an outer, then an inner join are generated. If we
are demoting b->c join in chain a LOUTER b LOUTER c then we must
demote a->b automatically, or otherwise the demotion of b->c doesn't
actually change anything in the query results. .
"""
aliases = list(aliases)
while aliases:
alias = aliases.pop(0)
if self.alias_map[alias].join_type == LOUTER:
self.alias_map[alias] = self.alias_map[alias].demote()
parent_alias = self.alias_map[alias].parent_alias
if self.alias_map[parent_alias].join_type == INNER:
aliases.append(parent_alias)
def reset_refcounts(self, to_counts):
"""
Reset reference counts for aliases so that they match the value passed
in `to_counts`.
"""
for alias, cur_refcount in self.alias_refcount.copy().items():
unref_amount = cur_refcount - to_counts.get(alias, 0)
self.unref_alias(alias, unref_amount)
def change_aliases(self, change_map):
"""
Change the aliases in change_map (which maps old-alias -> new-alias),
relabelling any references to them in select columns and the where
clause.
"""
# If keys and values of change_map were to intersect, an alias might be
# updated twice (e.g. T4 -> T5, T5 -> T6, so also T4 -> T6) depending
# on their order in change_map.
assert set(change_map).isdisjoint(change_map.values())
# 1. Update references in "select" (normal columns plus aliases),
# "group by" and "where".
self.where.relabel_aliases(change_map)
if isinstance(self.group_by, tuple):
self.group_by = tuple([col.relabeled_clone(change_map) for col in self.group_by])
self.select = tuple([col.relabeled_clone(change_map) for col in self.select])
self.annotations = self.annotations and {
key: col.relabeled_clone(change_map) for key, col in self.annotations.items()
}
# 2. Rename the alias in the internal table/alias datastructures.
for old_alias, new_alias in change_map.items():
if old_alias not in self.alias_map:
continue
alias_data = self.alias_map[old_alias].relabeled_clone(change_map)
self.alias_map[new_alias] = alias_data
self.alias_refcount[new_alias] = self.alias_refcount[old_alias]
del self.alias_refcount[old_alias]
del self.alias_map[old_alias]
table_aliases = self.table_map[alias_data.table_name]
for pos, alias in enumerate(table_aliases):
if alias == old_alias:
table_aliases[pos] = new_alias
break
self.external_aliases = {
# Table is aliased or it's being changed and thus is aliased.
change_map.get(alias, alias): (aliased or alias in change_map)
for alias, aliased in self.external_aliases.items()
}
def bump_prefix(self, other_query, exclude=None):
"""
Change the alias prefix to the next letter in the alphabet in a way
that the other query's aliases and this query's aliases will not
conflict. Even tables that previously had no alias will get an alias
after this call. To prevent changing aliases use the exclude parameter.
"""
def prefix_gen():
"""
Generate a sequence of characters in alphabetical order:
-> 'A', 'B', 'C', ...
When the alphabet is finished, the sequence will continue with the
Cartesian product:
-> 'AA', 'AB', 'AC', ...
"""
alphabet = ascii_uppercase
prefix = chr(ord(self.alias_prefix) + 1)
yield prefix
for n in count(1):
seq = alphabet[alphabet.index(prefix):] if prefix else alphabet
for s in product(seq, repeat=n):
yield ''.join(s)
prefix = None
if self.alias_prefix != other_query.alias_prefix:
# No clashes between self and outer query should be possible.
return
# Explicitly avoid infinite loop. The constant divider is based on how
# much depth recursive subquery references add to the stack. This value
# might need to be adjusted when adding or removing function calls from
# the code path in charge of performing these operations.
local_recursion_limit = sys.getrecursionlimit() // 16
for pos, prefix in enumerate(prefix_gen()):
if prefix not in self.subq_aliases:
self.alias_prefix = prefix
break
if pos > local_recursion_limit:
raise RecursionError(
'Maximum recursion depth exceeded: too many subqueries.'
)
self.subq_aliases = self.subq_aliases.union([self.alias_prefix])
other_query.subq_aliases = other_query.subq_aliases.union(self.subq_aliases)
if exclude is None:
exclude = {}
self.change_aliases({
alias: '%s%d' % (self.alias_prefix, pos)
for pos, alias in enumerate(self.alias_map)
if alias not in exclude
})
def get_initial_alias(self):
"""
Return the first alias for this query, after increasing its reference
count.
"""
if self.alias_map:
alias = self.base_table
self.ref_alias(alias)
else:
alias = self.join(self.base_table_class(self.get_meta().db_table, None))
return alias
def count_active_tables(self):
"""
Return the number of tables in this query with a non-zero reference
count. After execution, the reference counts are zeroed, so tables
added in compiler will not be seen by this method.
"""
return len([1 for count in self.alias_refcount.values() if count])
def join(self, join, reuse=None):
"""
Return an alias for the 'join', either reusing an existing alias for
that join or creating a new one. 'join' is either a base_table_class or
join_class.
The 'reuse' parameter can be either None which means all joins are
reusable, or it can be a set containing the aliases that can be reused.
A join is always created as LOUTER if the lhs alias is LOUTER to make
sure chains like t1 LOUTER t2 INNER t3 aren't generated. All new
joins are created as LOUTER if the join is nullable.
"""
reuse_aliases = [
a for a, j in self.alias_map.items()
if (reuse is None or a in reuse) and j.equals(join)
]
if reuse_aliases:
if join.table_alias in reuse_aliases:
reuse_alias = join.table_alias
else:
# Reuse the most recent alias of the joined table
# (a many-to-many relation may be joined multiple times).
reuse_alias = reuse_aliases[-1]
self.ref_alias(reuse_alias)
return reuse_alias
# No reuse is possible, so we need a new alias.
alias, _ = self.table_alias(join.table_name, create=True, filtered_relation=join.filtered_relation)
if join.join_type:
if self.alias_map[join.parent_alias].join_type == LOUTER or join.nullable:
join_type = LOUTER
else:
join_type = INNER
join.join_type = join_type
join.table_alias = alias
self.alias_map[alias] = join
return alias
def join_parent_model(self, opts, model, alias, seen):
"""
Make sure the given 'model' is joined in the query. If 'model' isn't
a parent of 'opts' or if it is None this method is a no-op.
The 'alias' is the root alias for starting the join, 'seen' is a dict
of model -> alias of existing joins. It must also contain a mapping
of None -> some alias. This will be returned in the no-op case.
"""
if model in seen:
return seen[model]
chain = opts.get_base_chain(model)
if not chain:
return alias
curr_opts = opts
for int_model in chain:
if int_model in seen:
curr_opts = int_model._meta
alias = seen[int_model]
continue
# Proxy model have elements in base chain
# with no parents, assign the new options
# object and skip to the next base in that
# case
if not curr_opts.parents[int_model]:
curr_opts = int_model._meta
continue
link_field = curr_opts.get_ancestor_link(int_model)
join_info = self.setup_joins([link_field.name], curr_opts, alias)
curr_opts = int_model._meta
alias = seen[int_model] = join_info.joins[-1]
return alias or seen[None]
def add_annotation(self, annotation, alias, is_summary=False, select=True):
"""Add a single annotation expression to the Query."""
annotation = annotation.resolve_expression(self, allow_joins=True, reuse=None,
summarize=is_summary)
if select:
self.append_annotation_mask([alias])
else:
self.set_annotation_mask(set(self.annotation_select).difference({alias}))
self.annotations[alias] = annotation
def resolve_expression(self, query, *args, **kwargs):
clone = self.clone()
# Subqueries need to use a different set of aliases than the outer query.
clone.bump_prefix(query)
clone.subquery = True
clone.where.resolve_expression(query, *args, **kwargs)
# Resolve combined queries.
if clone.combinator:
clone.combined_queries = tuple([
combined_query.resolve_expression(query, *args, **kwargs)
for combined_query in clone.combined_queries
])
for key, value in clone.annotations.items():
resolved = value.resolve_expression(query, *args, **kwargs)
if hasattr(resolved, 'external_aliases'):
resolved.external_aliases.update(clone.external_aliases)
clone.annotations[key] = resolved
# Outer query's aliases are considered external.
for alias, table in query.alias_map.items():
clone.external_aliases[alias] = (
(isinstance(table, Join) and table.join_field.related_model._meta.db_table != alias) or
(isinstance(table, BaseTable) and table.table_name != table.table_alias)
)
return clone
def get_external_cols(self):
exprs = chain(self.annotations.values(), self.where.children)
return [
col for col in self._gen_cols(exprs, include_external=True)
if col.alias in self.external_aliases
]
def get_group_by_cols(self, alias=None):
if alias:
return [Ref(alias, self)]
external_cols = self.get_external_cols()
if any(col.possibly_multivalued for col in external_cols):
return [self]
return external_cols
def as_sql(self, compiler, connection):
# Some backends (e.g. Oracle) raise an error when a subquery contains
# unnecessary ORDER BY clause.
if (
self.subquery and
not connection.features.ignores_unnecessary_order_by_in_subqueries
):
self.clear_ordering(force=False)
sql, params = self.get_compiler(connection=connection).as_sql()
if self.subquery:
sql = '(%s)' % sql
return sql, params
def resolve_lookup_value(self, value, can_reuse, allow_joins):
if hasattr(value, 'resolve_expression'):
value = value.resolve_expression(
self, reuse=can_reuse, allow_joins=allow_joins,
)
elif isinstance(value, (list, tuple)):
# The items of the iterable may be expressions and therefore need
# to be resolved independently.
values = (
self.resolve_lookup_value(sub_value, can_reuse, allow_joins)
for sub_value in value
)
type_ = type(value)
if hasattr(type_, '_make'): # namedtuple
return type_(*values)
return type_(values)
return value
def solve_lookup_type(self, lookup):
"""
Solve the lookup type from the lookup (e.g.: 'foobar__id__icontains').
"""
lookup_splitted = lookup.split(LOOKUP_SEP)
if self.annotations:
expression, expression_lookups = refs_expression(lookup_splitted, self.annotations)
if expression:
return expression_lookups, (), expression
_, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta())
field_parts = lookup_splitted[0:len(lookup_splitted) - len(lookup_parts)]
if len(lookup_parts) > 1 and not field_parts:
raise FieldError(
'Invalid lookup "%s" for model %s".' %
(lookup, self.get_meta().model.__name__)
)
return lookup_parts, field_parts, False
def check_query_object_type(self, value, opts, field):
"""
Check whether the object passed while querying is of the correct type.
If not, raise a ValueError specifying the wrong object.
"""
if hasattr(value, '_meta'):
if not check_rel_lookup_compatibility(value._meta.model, opts, field):
raise ValueError(
'Cannot query "%s": Must be "%s" instance.' %
(value, opts.object_name))
def check_related_objects(self, field, value, opts):
"""Check the type of object passed to query relations."""
if field.is_relation:
# Check that the field and the queryset use the same model in a
# query like .filter(author=Author.objects.all()). For example, the
# opts would be Author's (from the author field) and value.model
# would be Author.objects.all() queryset's .model (Author also).
# The field is the related field on the lhs side.
if (isinstance(value, Query) and not value.has_select_fields and
not check_rel_lookup_compatibility(value.model, opts, field)):
raise ValueError(
'Cannot use QuerySet for "%s": Use a QuerySet for "%s".' %
(value.model._meta.object_name, opts.object_name)
)
elif hasattr(value, '_meta'):
self.check_query_object_type(value, opts, field)
elif hasattr(value, '__iter__'):
for v in value:
self.check_query_object_type(v, opts, field)
def check_filterable(self, expression):
"""Raise an error if expression cannot be used in a WHERE clause."""
if (
hasattr(expression, 'resolve_expression') and
not getattr(expression, 'filterable', True)
):
raise NotSupportedError(
expression.__class__.__name__ + ' is disallowed in the filter '
'clause.'
)
if hasattr(expression, 'get_source_expressions'):
for expr in expression.get_source_expressions():
self.check_filterable(expr)
def build_lookup(self, lookups, lhs, rhs):
"""
Try to extract transforms and lookup from given lhs.
The lhs value is something that works like SQLExpression.
The rhs value is what the lookup is going to compare against.
The lookups is a list of names to extract using get_lookup()
and get_transform().
"""
# __exact is the default lookup if one isn't given.
*transforms, lookup_name = lookups or ['exact']
for name in transforms:
lhs = self.try_transform(lhs, name)
# First try get_lookup() so that the lookup takes precedence if the lhs
# supports both transform and lookup for the name.
lookup_class = lhs.get_lookup(lookup_name)
if not lookup_class:
if lhs.field.is_relation:
raise FieldError('Related Field got invalid lookup: {}'.format(lookup_name))
# A lookup wasn't found. Try to interpret the name as a transform
# and do an Exact lookup against it.
lhs = self.try_transform(lhs, lookup_name)
lookup_name = 'exact'
lookup_class = lhs.get_lookup(lookup_name)
if not lookup_class:
return
lookup = lookup_class(lhs, rhs)
# Interpret '__exact=None' as the sql 'is NULL'; otherwise, reject all
# uses of None as a query value unless the lookup supports it.
if lookup.rhs is None and not lookup.can_use_none_as_rhs:
if lookup_name not in ('exact', 'iexact'):
raise ValueError("Cannot use None as a query value")
return lhs.get_lookup('isnull')(lhs, True)
# For Oracle '' is equivalent to null. The check must be done at this
# stage because join promotion can't be done in the compiler. Using
# DEFAULT_DB_ALIAS isn't nice but it's the best that can be done here.
# A similar thing is done in is_nullable(), too.
if (
lookup_name == 'exact' and
lookup.rhs == '' and
connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls
):
return lhs.get_lookup('isnull')(lhs, True)
return lookup
def try_transform(self, lhs, name):
"""
Helper method for build_lookup(). Try to fetch and initialize
a transform for name parameter from lhs.
"""
transform_class = lhs.get_transform(name)
if transform_class:
return transform_class(lhs)
else:
output_field = lhs.output_field.__class__
suggested_lookups = difflib.get_close_matches(name, output_field.get_lookups())
if suggested_lookups:
suggestion = ', perhaps you meant %s?' % ' or '.join(suggested_lookups)
else:
suggestion = '.'
raise FieldError(
"Unsupported lookup '%s' for %s or join on the field not "
"permitted%s" % (name, output_field.__name__, suggestion)
)
def build_filter(self, filter_expr, branch_negated=False, current_negated=False,
can_reuse=None, allow_joins=True, split_subq=True,
check_filterable=True):
"""
Build a WhereNode for a single filter clause but don't add it
to this Query. Query.add_q() will then add this filter to the where
Node.
The 'branch_negated' tells us if the current branch contains any
negations. This will be used to determine if subqueries are needed.
The 'current_negated' is used to determine if the current filter is
negated or not and this will be used to determine if IS NULL filtering
is needed.
The difference between current_negated and branch_negated is that
branch_negated is set on first negation, but current_negated is
flipped for each negation.
Note that add_filter will not do any negating itself, that is done
upper in the code by add_q().
The 'can_reuse' is a set of reusable joins for multijoins.
The method will create a filter clause that can be added to the current
query. However, if the filter isn't added to the query then the caller
is responsible for unreffing the joins used.
"""
if isinstance(filter_expr, dict):
raise FieldError("Cannot parse keyword query as dict")
if isinstance(filter_expr, Q):
return self._add_q(
filter_expr,
branch_negated=branch_negated,
current_negated=current_negated,
used_aliases=can_reuse,
allow_joins=allow_joins,
split_subq=split_subq,
check_filterable=check_filterable,
)
if hasattr(filter_expr, 'resolve_expression'):
if not getattr(filter_expr, 'conditional', False):
raise TypeError('Cannot filter against a non-conditional expression.')
condition = filter_expr.resolve_expression(self, allow_joins=allow_joins)
if not isinstance(condition, Lookup):
condition = self.build_lookup(['exact'], condition, True)
return WhereNode([condition], connector=AND), []
arg, value = filter_expr
if not arg:
raise FieldError("Cannot parse keyword query %r" % arg)
lookups, parts, reffed_expression = self.solve_lookup_type(arg)
if check_filterable:
self.check_filterable(reffed_expression)
if not allow_joins and len(parts) > 1:
raise FieldError("Joined field references are not permitted in this query")
pre_joins = self.alias_refcount.copy()
value = self.resolve_lookup_value(value, can_reuse, allow_joins)
used_joins = {k for k, v in self.alias_refcount.items() if v > pre_joins.get(k, 0)}
if check_filterable:
self.check_filterable(value)
if reffed_expression:
condition = self.build_lookup(lookups, reffed_expression, value)
return WhereNode([condition], connector=AND), []
opts = self.get_meta()
alias = self.get_initial_alias()
allow_many = not branch_negated or not split_subq
try:
join_info = self.setup_joins(
parts, opts, alias, can_reuse=can_reuse, allow_many=allow_many,
)
# Prevent iterator from being consumed by check_related_objects()
if isinstance(value, Iterator):
value = list(value)
self.check_related_objects(join_info.final_field, value, join_info.opts)
# split_exclude() needs to know which joins were generated for the
# lookup parts
self._lookup_joins = join_info.joins
except MultiJoin as e:
return self.split_exclude(filter_expr, can_reuse, e.names_with_path)
# Update used_joins before trimming since they are reused to determine
# which joins could be later promoted to INNER.
used_joins.update(join_info.joins)
targets, alias, join_list = self.trim_joins(join_info.targets, join_info.joins, join_info.path)
if can_reuse is not None:
can_reuse.update(join_list)
if join_info.final_field.is_relation:
# No support for transforms for relational fields
num_lookups = len(lookups)
if num_lookups > 1:
raise FieldError('Related Field got invalid lookup: {}'.format(lookups[0]))
if len(targets) == 1:
col = self._get_col(targets[0], join_info.final_field, alias)
else:
col = MultiColSource(alias, targets, join_info.targets, join_info.final_field)
else:
col = self._get_col(targets[0], join_info.final_field, alias)
condition = self.build_lookup(lookups, col, value)
lookup_type = condition.lookup_name
clause = WhereNode([condition], connector=AND)
require_outer = lookup_type == 'isnull' and condition.rhs is True and not current_negated
if current_negated and (lookup_type != 'isnull' or condition.rhs is False) and condition.rhs is not None:
require_outer = True
if lookup_type != 'isnull':
# The condition added here will be SQL like this:
# NOT (col IS NOT NULL), where the first NOT is added in
# upper layers of code. The reason for addition is that if col
# is null, then col != someval will result in SQL "unknown"
# which isn't the same as in Python. The Python None handling
# is wanted, and it can be gotten by
# (col IS NULL OR col != someval)
# <=>
# NOT (col IS NOT NULL AND col = someval).
if (
self.is_nullable(targets[0]) or
self.alias_map[join_list[-1]].join_type == LOUTER
):
lookup_class = targets[0].get_lookup('isnull')
col = self._get_col(targets[0], join_info.targets[0], alias)
clause.add(lookup_class(col, False), AND)
# If someval is a nullable column, someval IS NOT NULL is
# added.
if isinstance(value, Col) and self.is_nullable(value.target):
lookup_class = value.target.get_lookup('isnull')
clause.add(lookup_class(value, False), AND)
return clause, used_joins if not require_outer else ()
def add_filter(self, filter_lhs, filter_rhs):
self.add_q(Q((filter_lhs, filter_rhs)))
def add_q(self, q_object):
"""
A preprocessor for the internal _add_q(). Responsible for doing final
join promotion.
"""
# For join promotion this case is doing an AND for the added q_object
# and existing conditions. So, any existing inner join forces the join
# type to remain inner. Existing outer joins can however be demoted.
# (Consider case where rel_a is LOUTER and rel_a__col=1 is added - if
# rel_a doesn't produce any rows, then the whole condition must fail.
# So, demotion is OK.
existing_inner = {a for a in self.alias_map if self.alias_map[a].join_type == INNER}
clause, _ = self._add_q(q_object, self.used_aliases)
if clause:
self.where.add(clause, AND)
self.demote_joins(existing_inner)
def build_where(self, filter_expr):
return self.build_filter(filter_expr, allow_joins=False)[0]
def clear_where(self):
self.where = WhereNode()
def _add_q(self, q_object, used_aliases, branch_negated=False,
current_negated=False, allow_joins=True, split_subq=True,
check_filterable=True):
"""Add a Q-object to the current filter."""
connector = q_object.connector
current_negated = current_negated ^ q_object.negated
branch_negated = branch_negated or q_object.negated
target_clause = WhereNode(connector=connector, negated=q_object.negated)
joinpromoter = JoinPromoter(q_object.connector, len(q_object.children), current_negated)
for child in q_object.children:
child_clause, needed_inner = self.build_filter(
child, can_reuse=used_aliases, branch_negated=branch_negated,
current_negated=current_negated, allow_joins=allow_joins,
split_subq=split_subq, check_filterable=check_filterable,
)
joinpromoter.add_votes(needed_inner)
if child_clause:
target_clause.add(child_clause, connector)
needed_inner = joinpromoter.update_join_types(self)
return target_clause, needed_inner
def build_filtered_relation_q(self, q_object, reuse, branch_negated=False, current_negated=False):
"""Add a FilteredRelation object to the current filter."""
connector = q_object.connector
current_negated ^= q_object.negated
branch_negated = branch_negated or q_object.negated
target_clause = WhereNode(connector=connector, negated=q_object.negated)
for child in q_object.children:
if isinstance(child, Node):
child_clause = self.build_filtered_relation_q(
child, reuse=reuse, branch_negated=branch_negated,
current_negated=current_negated,
)
else:
child_clause, _ = self.build_filter(
child, can_reuse=reuse, branch_negated=branch_negated,
current_negated=current_negated,
allow_joins=True, split_subq=False,
)
target_clause.add(child_clause, connector)
return target_clause
def add_filtered_relation(self, filtered_relation, alias):
filtered_relation.alias = alias
lookups = dict(get_children_from_q(filtered_relation.condition))
relation_lookup_parts, relation_field_parts, _ = self.solve_lookup_type(filtered_relation.relation_name)
if relation_lookup_parts:
raise ValueError(
"FilteredRelation's relation_name cannot contain lookups "
"(got %r)." % filtered_relation.relation_name
)
for lookup in chain(lookups):
lookup_parts, lookup_field_parts, _ = self.solve_lookup_type(lookup)
shift = 2 if not lookup_parts else 1
lookup_field_path = lookup_field_parts[:-shift]
for idx, lookup_field_part in enumerate(lookup_field_path):
if len(relation_field_parts) > idx:
if relation_field_parts[idx] != lookup_field_part:
raise ValueError(
"FilteredRelation's condition doesn't support "
"relations outside the %r (got %r)."
% (filtered_relation.relation_name, lookup)
)
else:
raise ValueError(
"FilteredRelation's condition doesn't support nested "
"relations deeper than the relation_name (got %r for "
"%r)." % (lookup, filtered_relation.relation_name)
)
self._filtered_relations[filtered_relation.alias] = filtered_relation
def names_to_path(self, names, opts, allow_many=True, fail_on_missing=False):
"""
Walk the list of names and turns them into PathInfo tuples. A single
name in 'names' can generate multiple PathInfos (m2m, for example).
'names' is the path of names to travel, 'opts' is the model Options we
start the name resolving from, 'allow_many' is as for setup_joins().
If fail_on_missing is set to True, then a name that can't be resolved
will generate a FieldError.
Return a list of PathInfo tuples. In addition return the final field
(the last used join field) and target (which is a field guaranteed to
contain the same value as the final field). Finally, return those names
that weren't found (which are likely transforms and the final lookup).
"""
path, names_with_path = [], []
for pos, name in enumerate(names):
cur_names_with_path = (name, [])
if name == 'pk':
name = opts.pk.name
field = None
filtered_relation = None
try:
field = opts.get_field(name)
except FieldDoesNotExist:
if name in self.annotation_select:
field = self.annotation_select[name].output_field
elif name in self._filtered_relations and pos == 0:
filtered_relation = self._filtered_relations[name]
if LOOKUP_SEP in filtered_relation.relation_name:
parts = filtered_relation.relation_name.split(LOOKUP_SEP)
filtered_relation_path, field, _, _ = self.names_to_path(
parts, opts, allow_many, fail_on_missing,
)
path.extend(filtered_relation_path[:-1])
else:
field = opts.get_field(filtered_relation.relation_name)
if field is not None:
# Fields that contain one-to-many relations with a generic
# model (like a GenericForeignKey) cannot generate reverse
# relations and therefore cannot be used for reverse querying.
if field.is_relation and not field.related_model:
raise FieldError(
"Field %r does not generate an automatic reverse "
"relation and therefore cannot be used for reverse "
"querying. If it is a GenericForeignKey, consider "
"adding a GenericRelation." % name
)
try:
model = field.model._meta.concrete_model
except AttributeError:
# QuerySet.annotate() may introduce fields that aren't
# attached to a model.
model = None
else:
# We didn't find the current field, so move position back
# one step.
pos -= 1
if pos == -1 or fail_on_missing:
available = sorted([
*get_field_names_from_opts(opts),
*self.annotation_select,
*self._filtered_relations,
])
raise FieldError("Cannot resolve keyword '%s' into field. "
"Choices are: %s" % (name, ", ".join(available)))
break
# Check if we need any joins for concrete inheritance cases (the
# field lives in parent, but we are currently in one of its
# children)
if model is not opts.model:
path_to_parent = opts.get_path_to_parent(model)
if path_to_parent:
path.extend(path_to_parent)
cur_names_with_path[1].extend(path_to_parent)
opts = path_to_parent[-1].to_opts
if hasattr(field, 'path_infos'):
if filtered_relation:
pathinfos = field.get_path_info(filtered_relation)
else:
pathinfos = field.path_infos
if not allow_many:
for inner_pos, p in enumerate(pathinfos):
if p.m2m:
cur_names_with_path[1].extend(pathinfos[0:inner_pos + 1])
names_with_path.append(cur_names_with_path)
raise MultiJoin(pos + 1, names_with_path)
last = pathinfos[-1]
path.extend(pathinfos)
final_field = last.join_field
opts = last.to_opts
targets = last.target_fields
cur_names_with_path[1].extend(pathinfos)
names_with_path.append(cur_names_with_path)
else:
# Local non-relational field.
final_field = field
targets = (field,)
if fail_on_missing and pos + 1 != len(names):
raise FieldError(
"Cannot resolve keyword %r into field. Join on '%s'"
" not permitted." % (names[pos + 1], name))
break
return path, final_field, targets, names[pos + 1:]
def setup_joins(self, names, opts, alias, can_reuse=None, allow_many=True):
"""
Compute the necessary table joins for the passage through the fields
given in 'names'. 'opts' is the Options class for the current model
(which gives the table we are starting from), 'alias' is the alias for
the table to start the joining from.
The 'can_reuse' defines the reverse foreign key joins we can reuse. It
can be None in which case all joins are reusable or a set of aliases
that can be reused. Note that non-reverse foreign keys are always
reusable when using setup_joins().
If 'allow_many' is False, then any reverse foreign key seen will
generate a MultiJoin exception.
Return the final field involved in the joins, the target field (used
for any 'where' constraint), the final 'opts' value, the joins, the
field path traveled to generate the joins, and a transform function
that takes a field and alias and is equivalent to `field.get_col(alias)`
in the simple case but wraps field transforms if they were included in
names.
The target field is the field containing the concrete value. Final
field can be something different, for example foreign key pointing to
that value. Final field is needed for example in some value
conversions (convert 'obj' in fk__id=obj to pk val using the foreign
key field for example).
"""
joins = [alias]
# The transform can't be applied yet, as joins must be trimmed later.
# To avoid making every caller of this method look up transforms
# directly, compute transforms here and create a partial that converts
# fields to the appropriate wrapped version.
def final_transformer(field, alias):
if not self.alias_cols:
alias = None
return field.get_col(alias)
# Try resolving all the names as fields first. If there's an error,
# treat trailing names as lookups until a field can be resolved.
last_field_exception = None
for pivot in range(len(names), 0, -1):
try:
path, final_field, targets, rest = self.names_to_path(
names[:pivot], opts, allow_many, fail_on_missing=True,
)
except FieldError as exc:
if pivot == 1:
# The first item cannot be a lookup, so it's safe
# to raise the field error here.
raise
else:
last_field_exception = exc
else:
# The transforms are the remaining items that couldn't be
# resolved into fields.
transforms = names[pivot:]
break
for name in transforms:
def transform(field, alias, *, name, previous):
try:
wrapped = previous(field, alias)
return self.try_transform(wrapped, name)
except FieldError:
# FieldError is raised if the transform doesn't exist.
if isinstance(final_field, Field) and last_field_exception:
raise last_field_exception
else:
raise
final_transformer = functools.partial(transform, name=name, previous=final_transformer)
# Then, add the path to the query's joins. Note that we can't trim
# joins at this stage - we will need the information about join type
# of the trimmed joins.
for join in path:
if join.filtered_relation:
filtered_relation = join.filtered_relation.clone()
table_alias = filtered_relation.alias
else:
filtered_relation = None
table_alias = None
opts = join.to_opts
if join.direct:
nullable = self.is_nullable(join.join_field)
else:
nullable = True
connection = self.join_class(
opts.db_table, alias, table_alias, INNER, join.join_field,
nullable, filtered_relation=filtered_relation,
)
reuse = can_reuse if join.m2m else None
alias = self.join(connection, reuse=reuse)
joins.append(alias)
if filtered_relation:
filtered_relation.path = joins[:]
return JoinInfo(final_field, targets, opts, joins, path, final_transformer)
def trim_joins(self, targets, joins, path):
"""
The 'target' parameter is the final field being joined to, 'joins'
is the full list of join aliases. The 'path' contain the PathInfos
used to create the joins.
Return the final target field and table alias and the new active
joins.
Always trim any direct join if the target column is already in the
previous table. Can't trim reverse joins as it's unknown if there's
anything on the other side of the join.
"""
joins = joins[:]
for pos, info in enumerate(reversed(path)):
if len(joins) == 1 or not info.direct:
break
if info.filtered_relation:
break
join_targets = {t.column for t in info.join_field.foreign_related_fields}
cur_targets = {t.column for t in targets}
if not cur_targets.issubset(join_targets):
break
targets_dict = {r[1].column: r[0] for r in info.join_field.related_fields if r[1].column in cur_targets}
targets = tuple(targets_dict[t.column] for t in targets)
self.unref_alias(joins.pop())
return targets, joins[-1], joins
@classmethod
def _gen_cols(cls, exprs, include_external=False):
for expr in exprs:
if isinstance(expr, Col):
yield expr
elif include_external and callable(getattr(expr, 'get_external_cols', None)):
yield from expr.get_external_cols()
elif hasattr(expr, 'get_source_expressions'):
yield from cls._gen_cols(
expr.get_source_expressions(),
include_external=include_external,
)
@classmethod
def _gen_col_aliases(cls, exprs):
yield from (expr.alias for expr in cls._gen_cols(exprs))
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
annotation = self.annotations.get(name)
if annotation is not None:
if not allow_joins:
for alias in self._gen_col_aliases([annotation]):
if isinstance(self.alias_map[alias], Join):
raise FieldError(
'Joined field references are not permitted in '
'this query'
)
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
if name not in self.annotation_select:
raise FieldError(
"Cannot aggregate over the '%s' alias. Use annotate() "
"to promote it." % name
)
return Ref(name, self.annotation_select[name])
else:
return annotation
else:
field_list = name.split(LOOKUP_SEP)
annotation = self.annotations.get(field_list[0])
if annotation is not None:
for transform in field_list[1:]:
annotation = self.try_transform(annotation, transform)
return annotation
join_info = self.setup_joins(field_list, self.get_meta(), self.get_initial_alias(), can_reuse=reuse)
targets, final_alias, join_list = self.trim_joins(join_info.targets, join_info.joins, join_info.path)
if not allow_joins and len(join_list) > 1:
raise FieldError('Joined field references are not permitted in this query')
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
# Verify that the last lookup in name is a field or a transform:
# transform_function() raises FieldError if not.
transform = join_info.transform_function(targets[0], final_alias)
if reuse is not None:
reuse.update(join_list)
return transform
def split_exclude(self, filter_expr, can_reuse, names_with_path):
"""
When doing an exclude against any kind of N-to-many relation, we need
to use a subquery. This method constructs the nested query, given the
original exclude filter (filter_expr) and the portion up to the first
N-to-many relation field.
For example, if the origin filter is ~Q(child__name='foo'), filter_expr
is ('child__name', 'foo') and can_reuse is a set of joins usable for
filters in the original query.
We will turn this into equivalent of:
WHERE NOT EXISTS(
SELECT 1
FROM child
WHERE name = 'foo' AND child.parent_id = parent.id
LIMIT 1
)
"""
# Generate the inner query.
query = self.__class__(self.model)
query._filtered_relations = self._filtered_relations
filter_lhs, filter_rhs = filter_expr
if isinstance(filter_rhs, OuterRef):
filter_rhs = OuterRef(filter_rhs)
elif isinstance(filter_rhs, F):
filter_rhs = OuterRef(filter_rhs.name)
query.add_filter(filter_lhs, filter_rhs)
query.clear_ordering(force=True)
# Try to have as simple as possible subquery -> trim leading joins from
# the subquery.
trimmed_prefix, contains_louter = query.trim_start(names_with_path)
col = query.select[0]
select_field = col.target
alias = col.alias
if alias in can_reuse:
pk = select_field.model._meta.pk
# Need to add a restriction so that outer query's filters are in effect for
# the subquery, too.
query.bump_prefix(self)
lookup_class = select_field.get_lookup('exact')
# Note that the query.select[0].alias is different from alias
# due to bump_prefix above.
lookup = lookup_class(pk.get_col(query.select[0].alias),
pk.get_col(alias))
query.where.add(lookup, AND)
query.external_aliases[alias] = True
lookup_class = select_field.get_lookup('exact')
lookup = lookup_class(col, ResolvedOuterRef(trimmed_prefix))
query.where.add(lookup, AND)
condition, needed_inner = self.build_filter(Exists(query))
if contains_louter:
or_null_condition, _ = self.build_filter(
('%s__isnull' % trimmed_prefix, True),
current_negated=True, branch_negated=True, can_reuse=can_reuse)
condition.add(or_null_condition, OR)
# Note that the end result will be:
# (outercol NOT IN innerq AND outercol IS NOT NULL) OR outercol IS NULL.
# This might look crazy but due to how IN works, this seems to be
# correct. If the IS NOT NULL check is removed then outercol NOT
# IN will return UNKNOWN. If the IS NULL check is removed, then if
# outercol IS NULL we will not match the row.
return condition, needed_inner
def set_empty(self):
self.where.add(NothingNode(), AND)
for query in self.combined_queries:
query.set_empty()
def is_empty(self):
return any(isinstance(c, NothingNode) for c in self.where.children)
def set_limits(self, low=None, high=None):
"""
Adjust the limits on the rows retrieved. Use low/high to set these,
as it makes it more Pythonic to read and write. When the SQL query is
created, convert them to the appropriate offset and limit values.
Apply any limits passed in here to the existing constraints. Add low
to the current low value and clamp both to any existing high value.
"""
if high is not None:
if self.high_mark is not None:
self.high_mark = min(self.high_mark, self.low_mark + high)
else:
self.high_mark = self.low_mark + high
if low is not None:
if self.high_mark is not None:
self.low_mark = min(self.high_mark, self.low_mark + low)
else:
self.low_mark = self.low_mark + low
if self.low_mark == self.high_mark:
self.set_empty()
def clear_limits(self):
"""Clear any existing limits."""
self.low_mark, self.high_mark = 0, None
@property
def is_sliced(self):
return self.low_mark != 0 or self.high_mark is not None
def has_limit_one(self):
return self.high_mark is not None and (self.high_mark - self.low_mark) == 1
def can_filter(self):
"""
Return True if adding filters to this instance is still possible.
Typically, this means no limits or offsets have been put on the results.
"""
return not self.is_sliced
def clear_select_clause(self):
"""Remove all fields from SELECT clause."""
self.select = ()
self.default_cols = False
self.select_related = False
self.set_extra_mask(())
self.set_annotation_mask(())
def clear_select_fields(self):
"""
Clear the list of fields to select (but not extra_select columns).
Some queryset types completely replace any existing list of select
columns.
"""
self.select = ()
self.values_select = ()
def add_select_col(self, col, name):
self.select += col,
self.values_select += name,
def set_select(self, cols):
self.default_cols = False
self.select = tuple(cols)
def add_distinct_fields(self, *field_names):
"""
Add and resolve the given fields to the query's "distinct on" clause.
"""
self.distinct_fields = field_names
self.distinct = True
def add_fields(self, field_names, allow_m2m=True):
"""
Add the given (model) fields to the select set. Add the field names in
the order specified.
"""
alias = self.get_initial_alias()
opts = self.get_meta()
try:
cols = []
for name in field_names:
# Join promotion note - we must not remove any rows here, so
# if there is no existing joins, use outer join.
join_info = self.setup_joins(name.split(LOOKUP_SEP), opts, alias, allow_many=allow_m2m)
targets, final_alias, joins = self.trim_joins(
join_info.targets,
join_info.joins,
join_info.path,
)
for target in targets:
cols.append(join_info.transform_function(target, final_alias))
if cols:
self.set_select(cols)
except MultiJoin:
raise FieldError("Invalid field name: '%s'" % name)
except FieldError:
if LOOKUP_SEP in name:
# For lookups spanning over relationships, show the error
# from the model on which the lookup failed.
raise
elif name in self.annotations:
raise FieldError(
"Cannot select the '%s' alias. Use annotate() to promote "
"it." % name
)
else:
names = sorted([
*get_field_names_from_opts(opts), *self.extra,
*self.annotation_select, *self._filtered_relations
])
raise FieldError("Cannot resolve keyword %r into field. "
"Choices are: %s" % (name, ", ".join(names)))
def add_ordering(self, *ordering):
"""
Add items from the 'ordering' sequence to the query's "order by"
clause. These items are either field names (not column names) --
possibly with a direction prefix ('-' or '?') -- or OrderBy
expressions.
If 'ordering' is empty, clear all ordering from the query.
"""
errors = []
for item in ordering:
if isinstance(item, str):
if item == '?':
continue
if item.startswith('-'):
item = item[1:]
if item in self.annotations:
continue
if self.extra and item in self.extra:
continue
# names_to_path() validates the lookup. A descriptive
# FieldError will be raise if it's not.
self.names_to_path(item.split(LOOKUP_SEP), self.model._meta)
elif not hasattr(item, 'resolve_expression'):
errors.append(item)
if getattr(item, 'contains_aggregate', False):
raise FieldError(
'Using an aggregate in order_by() without also including '
'it in annotate() is not allowed: %s' % item
)
if errors:
raise FieldError('Invalid order_by arguments: %s' % errors)
if ordering:
self.order_by += ordering
else:
self.default_ordering = False
def clear_ordering(self, force=False, clear_default=True):
"""
Remove any ordering settings if the current query allows it without
side effects, set 'force' to True to clear the ordering regardless.
If 'clear_default' is True, there will be no ordering in the resulting
query (not even the model's default).
"""
if not force and (self.is_sliced or self.distinct_fields or self.select_for_update):
return
self.order_by = ()
self.extra_order_by = ()
if clear_default:
self.default_ordering = False
def set_group_by(self, allow_aliases=True):
"""
Expand the GROUP BY clause required by the query.
This will usually be the set of all non-aggregate fields in the
return data. If the database backend supports grouping by the
primary key, and the query would be equivalent, the optimization
will be made automatically.
"""
# Column names from JOINs to check collisions with aliases.
if allow_aliases:
column_names = set()
seen_models = set()
for join in list(self.alias_map.values())[1:]: # Skip base table.
model = join.join_field.related_model
if model not in seen_models:
column_names.update({
field.column
for field in model._meta.local_concrete_fields
})
seen_models.add(model)
group_by = list(self.select)
if self.annotation_select:
for alias, annotation in self.annotation_select.items():
if not allow_aliases or alias in column_names:
alias = None
group_by_cols = annotation.get_group_by_cols(alias=alias)
group_by.extend(group_by_cols)
self.group_by = tuple(group_by)
def add_select_related(self, fields):
"""
Set up the select_related data structure so that we only select
certain related models (as opposed to all models, when
self.select_related=True).
"""
if isinstance(self.select_related, bool):
field_dict = {}
else:
field_dict = self.select_related
for field in fields:
d = field_dict
for part in field.split(LOOKUP_SEP):
d = d.setdefault(part, {})
self.select_related = field_dict
def add_extra(self, select, select_params, where, params, tables, order_by):
"""
Add data to the various extra_* attributes for user-created additions
to the query.
"""
if select:
# We need to pair any placeholder markers in the 'select'
# dictionary with their parameters in 'select_params' so that
# subsequent updates to the select dictionary also adjust the
# parameters appropriately.
select_pairs = {}
if select_params:
param_iter = iter(select_params)
else:
param_iter = iter([])
for name, entry in select.items():
entry = str(entry)
entry_params = []
pos = entry.find("%s")
while pos != -1:
if pos == 0 or entry[pos - 1] != '%':
entry_params.append(next(param_iter))
pos = entry.find("%s", pos + 2)
select_pairs[name] = (entry, entry_params)
self.extra.update(select_pairs)
if where or params:
self.where.add(ExtraWhere(where, params), AND)
if tables:
self.extra_tables += tuple(tables)
if order_by:
self.extra_order_by = order_by
def clear_deferred_loading(self):
"""Remove any fields from the deferred loading set."""
self.deferred_loading = (frozenset(), True)
def add_deferred_loading(self, field_names):
"""
Add the given list of model field names to the set of fields to
exclude from loading from the database when automatic column selection
is done. Add the new field names to any existing field names that
are deferred (or removed from any existing field names that are marked
as the only ones for immediate loading).
"""
# Fields on related models are stored in the literal double-underscore
# format, so that we can use a set datastructure. We do the foo__bar
# splitting and handling when computing the SQL column names (as part of
# get_columns()).
existing, defer = self.deferred_loading
if defer:
# Add to existing deferred names.
self.deferred_loading = existing.union(field_names), True
else:
# Remove names from the set of any existing "immediate load" names.
if new_existing := existing.difference(field_names):
self.deferred_loading = new_existing, False
else:
self.clear_deferred_loading()
if new_only := set(field_names).difference(existing):
self.deferred_loading = new_only, True
def add_immediate_loading(self, field_names):
"""
Add the given list of model field names to the set of fields to
retrieve when the SQL is executed ("immediate loading" fields). The
field names replace any existing immediate loading field names. If
there are field names already specified for deferred loading, remove
those names from the new field_names before storing the new names
for immediate loading. (That is, immediate loading overrides any
existing immediate values, but respects existing deferrals.)
"""
existing, defer = self.deferred_loading
field_names = set(field_names)
if 'pk' in field_names:
field_names.remove('pk')
field_names.add(self.get_meta().pk.name)
if defer:
# Remove any existing deferred names from the current set before
# setting the new names.
self.deferred_loading = field_names.difference(existing), False
else:
# Replace any existing "immediate load" field names.
self.deferred_loading = frozenset(field_names), False
def get_loaded_field_names(self):
"""
If any fields are marked to be deferred, return a dictionary mapping
models to a set of names in those fields that will be loaded. If a
model is not in the returned dictionary, none of its fields are
deferred.
If no fields are marked for deferral, return an empty dictionary.
"""
# We cache this because we call this function multiple times
# (compiler.fill_related_selections, query.iterator)
try:
return self._loaded_field_names_cache
except AttributeError:
collection = {}
self.deferred_to_data(collection, self.get_loaded_field_names_cb)
self._loaded_field_names_cache = collection
return collection
def get_loaded_field_names_cb(self, target, model, fields):
"""Callback used by get_deferred_field_names()."""
target[model] = {f.attname for f in fields}
def set_annotation_mask(self, names):
"""Set the mask of annotations that will be returned by the SELECT."""
if names is None:
self.annotation_select_mask = None
else:
self.annotation_select_mask = set(names)
self._annotation_select_cache = None
def append_annotation_mask(self, names):
if self.annotation_select_mask is not None:
self.set_annotation_mask(self.annotation_select_mask.union(names))
def set_extra_mask(self, names):
"""
Set the mask of extra select items that will be returned by SELECT.
Don't remove them from the Query since they might be used later.
"""
if names is None:
self.extra_select_mask = None
else:
self.extra_select_mask = set(names)
self._extra_select_cache = None
def set_values(self, fields):
self.select_related = False
self.clear_deferred_loading()
self.clear_select_fields()
if fields:
field_names = []
extra_names = []
annotation_names = []
if not self.extra and not self.annotations:
# Shortcut - if there are no extra or annotations, then
# the values() clause must be just field names.
field_names = list(fields)
else:
self.default_cols = False
for f in fields:
if f in self.extra_select:
extra_names.append(f)
elif f in self.annotation_select:
annotation_names.append(f)
else:
field_names.append(f)
self.set_extra_mask(extra_names)
self.set_annotation_mask(annotation_names)
selected = frozenset(field_names + extra_names + annotation_names)
else:
field_names = [f.attname for f in self.model._meta.concrete_fields]
selected = frozenset(field_names)
# Selected annotations must be known before setting the GROUP BY
# clause.
if self.group_by is True:
self.add_fields((f.attname for f in self.model._meta.concrete_fields), False)
# Disable GROUP BY aliases to avoid orphaning references to the
# SELECT clause which is about to be cleared.
self.set_group_by(allow_aliases=False)
self.clear_select_fields()
elif self.group_by:
# Resolve GROUP BY annotation references if they are not part of
# the selected fields anymore.
group_by = []
for expr in self.group_by:
if isinstance(expr, Ref) and expr.refs not in selected:
expr = self.annotations[expr.refs]
group_by.append(expr)
self.group_by = tuple(group_by)
self.values_select = tuple(field_names)
self.add_fields(field_names, True)
@property
def annotation_select(self):
"""
Return the dictionary of aggregate columns that are not masked and
should be used in the SELECT clause. Cache this result for performance.
"""
if self._annotation_select_cache is not None:
return self._annotation_select_cache
elif not self.annotations:
return {}
elif self.annotation_select_mask is not None:
self._annotation_select_cache = {
k: v for k, v in self.annotations.items()
if k in self.annotation_select_mask
}
return self._annotation_select_cache
else:
return self.annotations
@property
def extra_select(self):
if self._extra_select_cache is not None:
return self._extra_select_cache
if not self.extra:
return {}
elif self.extra_select_mask is not None:
self._extra_select_cache = {
k: v for k, v in self.extra.items()
if k in self.extra_select_mask
}
return self._extra_select_cache
else:
return self.extra
def trim_start(self, names_with_path):
"""
Trim joins from the start of the join path. The candidates for trim
are the PathInfos in names_with_path structure that are m2m joins.
Also set the select column so the start matches the join.
This method is meant to be used for generating the subquery joins &
cols in split_exclude().
Return a lookup usable for doing outerq.filter(lookup=self) and a
boolean indicating if the joins in the prefix contain a LEFT OUTER join.
_"""
all_paths = []
for _, paths in names_with_path:
all_paths.extend(paths)
contains_louter = False
# Trim and operate only on tables that were generated for
# the lookup part of the query. That is, avoid trimming
# joins generated for F() expressions.
lookup_tables = [
t for t in self.alias_map
if t in self._lookup_joins or t == self.base_table
]
for trimmed_paths, path in enumerate(all_paths):
if path.m2m:
break
if self.alias_map[lookup_tables[trimmed_paths + 1]].join_type == LOUTER:
contains_louter = True
alias = lookup_tables[trimmed_paths]
self.unref_alias(alias)
# The path.join_field is a Rel, lets get the other side's field
join_field = path.join_field.field
# Build the filter prefix.
paths_in_prefix = trimmed_paths
trimmed_prefix = []
for name, path in names_with_path:
if paths_in_prefix - len(path) < 0:
break
trimmed_prefix.append(name)
paths_in_prefix -= len(path)
trimmed_prefix.append(
join_field.foreign_related_fields[0].name)
trimmed_prefix = LOOKUP_SEP.join(trimmed_prefix)
# Lets still see if we can trim the first join from the inner query
# (that is, self). We can't do this for:
# - LEFT JOINs because we would miss those rows that have nothing on
# the outer side,
# - INNER JOINs from filtered relations because we would miss their
# filters.
first_join = self.alias_map[lookup_tables[trimmed_paths + 1]]
if first_join.join_type != LOUTER and not first_join.filtered_relation:
select_fields = [r[0] for r in join_field.related_fields]
select_alias = lookup_tables[trimmed_paths + 1]
self.unref_alias(lookup_tables[trimmed_paths])
extra_restriction = join_field.get_extra_restriction(None, lookup_tables[trimmed_paths + 1])
if extra_restriction:
self.where.add(extra_restriction, AND)
else:
# TODO: It might be possible to trim more joins from the start of the
# inner query if it happens to have a longer join chain containing the
# values in select_fields. Lets punt this one for now.
select_fields = [r[1] for r in join_field.related_fields]
select_alias = lookup_tables[trimmed_paths]
# The found starting point is likely a join_class instead of a
# base_table_class reference. But the first entry in the query's FROM
# clause must not be a JOIN.
for table in self.alias_map:
if self.alias_refcount[table] > 0:
self.alias_map[table] = self.base_table_class(
self.alias_map[table].table_name,
table,
)
break
self.set_select([f.get_col(select_alias) for f in select_fields])
return trimmed_prefix, contains_louter
def is_nullable(self, field):
"""
Check if the given field should be treated as nullable.
Some backends treat '' as null and Django treats such fields as
nullable for those backends. In such situations field.null can be
False even if we should treat the field as nullable.
"""
# We need to use DEFAULT_DB_ALIAS here, as QuerySet does not have
# (nor should it have) knowledge of which connection is going to be
# used. The proper fix would be to defer all decisions where
# is_nullable() is needed to the compiler stage, but that is not easy
# to do currently.
return field.null or (
field.empty_strings_allowed and
connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls
)
def get_order_dir(field, default='ASC'):
"""
Return the field name and direction for an order specification. For
example, '-foo' is returned as ('foo', 'DESC').
The 'default' param is used to indicate which way no prefix (or a '+'
prefix) should sort. The '-' prefix always sorts the opposite way.
"""
dirn = ORDER_DIR[default]
if field[0] == '-':
return field[1:], dirn[1]
return field, dirn[0]
def add_to_dict(data, key, value):
"""
Add "value" to the set of values for "key", whether or not "key" already
exists.
"""
if key in data:
data[key].add(value)
else:
data[key] = {value}
def is_reverse_o2o(field):
"""
Check if the given field is reverse-o2o. The field is expected to be some
sort of relation field or related object.
"""
return field.is_relation and field.one_to_one and not field.concrete
class JoinPromoter:
"""
A class to abstract away join promotion problems for complex filter
conditions.
"""
def __init__(self, connector, num_children, negated):
self.connector = connector
self.negated = negated
if self.negated:
if connector == AND:
self.effective_connector = OR
else:
self.effective_connector = AND
else:
self.effective_connector = self.connector
self.num_children = num_children
# Maps of table alias to how many times it is seen as required for
# inner and/or outer joins.
self.votes = Counter()
def __repr__(self):
return (
f'{self.__class__.__qualname__}(connector={self.connector!r}, '
f'num_children={self.num_children!r}, negated={self.negated!r})'
)
def add_votes(self, votes):
"""
Add single vote per item to self.votes. Parameter can be any
iterable.
"""
self.votes.update(votes)
def update_join_types(self, query):
"""
Change join types so that the generated query is as efficient as
possible, but still correct. So, change as many joins as possible
to INNER, but don't make OUTER joins INNER if that could remove
results from the query.
"""
to_promote = set()
to_demote = set()
# The effective_connector is used so that NOT (a AND b) is treated
# similarly to (a OR b) for join promotion.
for table, votes in self.votes.items():
# We must use outer joins in OR case when the join isn't contained
# in all of the joins. Otherwise the INNER JOIN itself could remove
# valid results. Consider the case where a model with rel_a and
# rel_b relations is queried with rel_a__col=1 | rel_b__col=2. Now,
# if rel_a join doesn't produce any results is null (for example
# reverse foreign key or null value in direct foreign key), and
# there is a matching row in rel_b with col=2, then an INNER join
# to rel_a would remove a valid match from the query. So, we need
# to promote any existing INNER to LOUTER (it is possible this
# promotion in turn will be demoted later on).
if self.effective_connector == 'OR' and votes < self.num_children:
to_promote.add(table)
# If connector is AND and there is a filter that can match only
# when there is a joinable row, then use INNER. For example, in
# rel_a__col=1 & rel_b__col=2, if either of the rels produce NULL
# as join output, then the col=1 or col=2 can't match (as
# NULL=anything is always false).
# For the OR case, if all children voted for a join to be inner,
# then we can use INNER for the join. For example:
# (rel_a__col__icontains=Alex | rel_a__col__icontains=Russell)
# then if rel_a doesn't produce any rows, the whole condition
# can't match. Hence we can safely use INNER join.
if self.effective_connector == 'AND' or (
self.effective_connector == 'OR' and votes == self.num_children):
to_demote.add(table)
# Finally, what happens in cases where we have:
# (rel_a__col=1|rel_b__col=2) & rel_a__col__gte=0
# Now, we first generate the OR clause, and promote joins for it
# in the first if branch above. Both rel_a and rel_b are promoted
# to LOUTER joins. After that we do the AND case. The OR case
# voted no inner joins but the rel_a__col__gte=0 votes inner join
# for rel_a. We demote it back to INNER join (in AND case a single
# vote is enough). The demotion is OK, if rel_a doesn't produce
# rows, then the rel_a__col__gte=0 clause can't be true, and thus
# the whole clause must be false. So, it is safe to use INNER
# join.
# Note that in this example we could just as well have the __gte
# clause and the OR clause swapped. Or we could replace the __gte
# clause with an OR clause containing rel_a__col=1|rel_a__col=2,
# and again we could safely demote to INNER.
query.promote_joins(to_promote)
query.demote_joins(to_demote)
return to_demote
|
c29b0b1d81289f2b467f9dc08399a20a8fb97ea9dd9287b0c5f5a37857a36963 | import collections
import json
import re
from functools import partial
from itertools import chain
from django.core.exceptions import EmptyResultSet, FieldError
from django.db import DatabaseError, NotSupportedError
from django.db.models.constants import LOOKUP_SEP
from django.db.models.expressions import F, OrderBy, RawSQL, Ref, Value
from django.db.models.functions import Cast, Random
from django.db.models.query_utils import select_related_descend
from django.db.models.sql.constants import (
CURSOR, GET_ITERATOR_CHUNK_SIZE, MULTI, NO_RESULTS, ORDER_DIR, SINGLE,
)
from django.db.models.sql.query import Query, get_order_dir
from django.db.transaction import TransactionManagementError
from django.utils.functional import cached_property
from django.utils.hashable import make_hashable
from django.utils.regex_helper import _lazy_re_compile
class SQLCompiler:
# Multiline ordering SQL clause may appear from RawSQL.
ordering_parts = _lazy_re_compile(
r'^(.*)\s(?:ASC|DESC).*',
re.MULTILINE | re.DOTALL,
)
def __init__(self, query, connection, using, elide_empty=True):
self.query = query
self.connection = connection
self.using = using
# Some queries, e.g. coalesced aggregation, need to be executed even if
# they would return an empty result set.
self.elide_empty = elide_empty
self.quote_cache = {'*': '*'}
# The select, klass_info, and annotations are needed by QuerySet.iterator()
# these are set as a side-effect of executing the query. Note that we calculate
# separately a list of extra select columns needed for grammatical correctness
# of the query, but these columns are not included in self.select.
self.select = None
self.annotation_col_map = None
self.klass_info = None
self._meta_ordering = None
def __repr__(self):
return (
f'<{self.__class__.__qualname__} '
f'model={self.query.model.__qualname__} '
f'connection={self.connection!r} using={self.using!r}>'
)
def setup_query(self):
if all(self.query.alias_refcount[a] == 0 for a in self.query.alias_map):
self.query.get_initial_alias()
self.select, self.klass_info, self.annotation_col_map = self.get_select()
self.col_count = len(self.select)
def pre_sql_setup(self):
"""
Do any necessary class setup immediately prior to producing SQL. This
is for things that can't necessarily be done in __init__ because we
might not have all the pieces in place at that time.
"""
self.setup_query()
order_by = self.get_order_by()
self.where, self.having = self.query.where.split_having()
extra_select = self.get_extra_select(order_by, self.select)
self.has_extra_select = bool(extra_select)
group_by = self.get_group_by(self.select + extra_select, order_by)
return extra_select, order_by, group_by
def get_group_by(self, select, order_by):
"""
Return a list of 2-tuples of form (sql, params).
The logic of what exactly the GROUP BY clause contains is hard
to describe in other words than "if it passes the test suite,
then it is correct".
"""
# Some examples:
# SomeModel.objects.annotate(Count('somecol'))
# GROUP BY: all fields of the model
#
# SomeModel.objects.values('name').annotate(Count('somecol'))
# GROUP BY: name
#
# SomeModel.objects.annotate(Count('somecol')).values('name')
# GROUP BY: all cols of the model
#
# SomeModel.objects.values('name', 'pk').annotate(Count('somecol')).values('pk')
# GROUP BY: name, pk
#
# SomeModel.objects.values('name').annotate(Count('somecol')).values('pk')
# GROUP BY: name, pk
#
# In fact, the self.query.group_by is the minimal set to GROUP BY. It
# can't be ever restricted to a smaller set, but additional columns in
# HAVING, ORDER BY, and SELECT clauses are added to it. Unfortunately
# the end result is that it is impossible to force the query to have
# a chosen GROUP BY clause - you can almost do this by using the form:
# .values(*wanted_cols).annotate(AnAggregate())
# but any later annotations, extra selects, values calls that
# refer some column outside of the wanted_cols, order_by, or even
# filter calls can alter the GROUP BY clause.
# The query.group_by is either None (no GROUP BY at all), True
# (group by select fields), or a list of expressions to be added
# to the group by.
if self.query.group_by is None:
return []
expressions = []
if self.query.group_by is not True:
# If the group by is set to a list (by .values() call most likely),
# then we need to add everything in it to the GROUP BY clause.
# Backwards compatibility hack for setting query.group_by. Remove
# when we have public API way of forcing the GROUP BY clause.
# Converts string references to expressions.
for expr in self.query.group_by:
if not hasattr(expr, 'as_sql'):
expressions.append(self.query.resolve_ref(expr))
else:
expressions.append(expr)
# Note that even if the group_by is set, it is only the minimal
# set to group by. So, we need to add cols in select, order_by, and
# having into the select in any case.
ref_sources = {
expr.source for expr in expressions if isinstance(expr, Ref)
}
for expr, _, _ in select:
# Skip members of the select clause that are already included
# by reference.
if expr in ref_sources:
continue
cols = expr.get_group_by_cols()
for col in cols:
expressions.append(col)
if not self._meta_ordering:
for expr, (sql, params, is_ref) in order_by:
# Skip references to the SELECT clause, as all expressions in
# the SELECT clause are already part of the GROUP BY.
if not is_ref:
expressions.extend(expr.get_group_by_cols())
having_group_by = self.having.get_group_by_cols() if self.having else ()
for expr in having_group_by:
expressions.append(expr)
result = []
seen = set()
expressions = self.collapse_group_by(expressions, having_group_by)
for expr in expressions:
sql, params = self.compile(expr)
sql, params = expr.select_format(self, sql, params)
params_hash = make_hashable(params)
if (sql, params_hash) not in seen:
result.append((sql, params))
seen.add((sql, params_hash))
return result
def collapse_group_by(self, expressions, having):
# If the DB can group by primary key, then group by the primary key of
# query's main model. Note that for PostgreSQL the GROUP BY clause must
# include the primary key of every table, but for MySQL it is enough to
# have the main table's primary key.
if self.connection.features.allows_group_by_pk:
# Determine if the main model's primary key is in the query.
pk = None
for expr in expressions:
# Is this a reference to query's base table primary key? If the
# expression isn't a Col-like, then skip the expression.
if (getattr(expr, 'target', None) == self.query.model._meta.pk and
getattr(expr, 'alias', None) == self.query.base_table):
pk = expr
break
# If the main model's primary key is in the query, group by that
# field, HAVING expressions, and expressions associated with tables
# that don't have a primary key included in the grouped columns.
if pk:
pk_aliases = {
expr.alias for expr in expressions
if hasattr(expr, 'target') and expr.target.primary_key
}
expressions = [pk] + [
expr for expr in expressions
if expr in having or (
getattr(expr, 'alias', None) is not None and expr.alias not in pk_aliases
)
]
elif self.connection.features.allows_group_by_selected_pks:
# Filter out all expressions associated with a table's primary key
# present in the grouped columns. This is done by identifying all
# tables that have their primary key included in the grouped
# columns and removing non-primary key columns referring to them.
# Unmanaged models are excluded because they could be representing
# database views on which the optimization might not be allowed.
pks = {
expr for expr in expressions
if (
hasattr(expr, 'target') and
expr.target.primary_key and
self.connection.features.allows_group_by_selected_pks_on_model(expr.target.model)
)
}
aliases = {expr.alias for expr in pks}
expressions = [
expr for expr in expressions if expr in pks or getattr(expr, 'alias', None) not in aliases
]
return expressions
def get_select(self):
"""
Return three values:
- a list of 3-tuples of (expression, (sql, params), alias)
- a klass_info structure,
- a dictionary of annotations
The (sql, params) is what the expression will produce, and alias is the
"AS alias" for the column (possibly None).
The klass_info structure contains the following information:
- The base model of the query.
- Which columns for that model are present in the query (by
position of the select clause).
- related_klass_infos: [f, klass_info] to descent into
The annotations is a dictionary of {'attname': column position} values.
"""
select = []
klass_info = None
annotations = {}
select_idx = 0
for alias, (sql, params) in self.query.extra_select.items():
annotations[alias] = select_idx
select.append((RawSQL(sql, params), alias))
select_idx += 1
assert not (self.query.select and self.query.default_cols)
if self.query.default_cols:
cols = self.get_default_columns()
else:
# self.query.select is a special case. These columns never go to
# any model.
cols = self.query.select
if cols:
select_list = []
for col in cols:
select_list.append(select_idx)
select.append((col, None))
select_idx += 1
klass_info = {
'model': self.query.model,
'select_fields': select_list,
}
for alias, annotation in self.query.annotation_select.items():
annotations[alias] = select_idx
select.append((annotation, alias))
select_idx += 1
if self.query.select_related:
related_klass_infos = self.get_related_selections(select)
klass_info['related_klass_infos'] = related_klass_infos
def get_select_from_parent(klass_info):
for ki in klass_info['related_klass_infos']:
if ki['from_parent']:
ki['select_fields'] = (klass_info['select_fields'] +
ki['select_fields'])
get_select_from_parent(ki)
get_select_from_parent(klass_info)
ret = []
for col, alias in select:
try:
sql, params = self.compile(col)
except EmptyResultSet:
empty_result_set_value = getattr(col, 'empty_result_set_value', NotImplemented)
if empty_result_set_value is NotImplemented:
# Select a predicate that's always False.
sql, params = '0', ()
else:
sql, params = self.compile(Value(empty_result_set_value))
else:
sql, params = col.select_format(self, sql, params)
ret.append((col, (sql, params), alias))
return ret, klass_info, annotations
def _order_by_pairs(self):
if self.query.extra_order_by:
ordering = self.query.extra_order_by
elif not self.query.default_ordering:
ordering = self.query.order_by
elif self.query.order_by:
ordering = self.query.order_by
elif self.query.get_meta().ordering:
ordering = self.query.get_meta().ordering
self._meta_ordering = ordering
else:
ordering = []
if self.query.standard_ordering:
default_order, _ = ORDER_DIR['ASC']
else:
default_order, _ = ORDER_DIR['DESC']
for field in ordering:
if hasattr(field, 'resolve_expression'):
if isinstance(field, Value):
# output_field must be resolved for constants.
field = Cast(field, field.output_field)
if not isinstance(field, OrderBy):
field = field.asc()
if not self.query.standard_ordering:
field = field.copy()
field.reverse_ordering()
yield field, False
continue
if field == '?': # random
yield OrderBy(Random()), False
continue
col, order = get_order_dir(field, default_order)
descending = order == 'DESC'
if col in self.query.annotation_select:
# Reference to expression in SELECT clause
yield (
OrderBy(
Ref(col, self.query.annotation_select[col]),
descending=descending,
),
True,
)
continue
if col in self.query.annotations:
# References to an expression which is masked out of the SELECT
# clause.
if self.query.combinator and self.select:
# Don't use the resolved annotation because other
# combinated queries might define it differently.
expr = F(col)
else:
expr = self.query.annotations[col]
if isinstance(expr, Value):
# output_field must be resolved for constants.
expr = Cast(expr, expr.output_field)
yield OrderBy(expr, descending=descending), False
continue
if '.' in field:
# This came in through an extra(order_by=...) addition. Pass it
# on verbatim.
table, col = col.split('.', 1)
yield (
OrderBy(
RawSQL('%s.%s' % (self.quote_name_unless_alias(table), col), []),
descending=descending,
),
False,
)
continue
if self.query.extra and col in self.query.extra:
if col in self.query.extra_select:
yield (
OrderBy(Ref(col, RawSQL(*self.query.extra[col])), descending=descending),
True,
)
else:
yield (
OrderBy(RawSQL(*self.query.extra[col]), descending=descending),
False,
)
else:
if self.query.combinator and self.select:
# Don't use the first model's field because other
# combinated queries might define it differently.
yield OrderBy(F(col), descending=descending), False
else:
# 'col' is of the form 'field' or 'field1__field2' or
# '-field1__field2__field', etc.
yield from self.find_ordering_name(
field, self.query.get_meta(), default_order=default_order,
)
def get_order_by(self):
"""
Return a list of 2-tuples of the form (expr, (sql, params, is_ref)) for
the ORDER BY clause.
The order_by clause can alter the select clause (for example it can add
aliases to clauses that do not yet have one, or it can add totally new
select clauses).
"""
result = []
seen = set()
for expr, is_ref in self._order_by_pairs():
resolved = expr.resolve_expression(self.query, allow_joins=True, reuse=None)
if self.query.combinator and self.select:
src = resolved.get_source_expressions()[0]
expr_src = expr.get_source_expressions()[0]
# Relabel order by columns to raw numbers if this is a combined
# query; necessary since the columns can't be referenced by the
# fully qualified name and the simple column names may collide.
for idx, (sel_expr, _, col_alias) in enumerate(self.select):
if is_ref and col_alias == src.refs:
src = src.source
elif col_alias and not (
isinstance(expr_src, F) and col_alias == expr_src.name
):
continue
if src == sel_expr:
resolved.set_source_expressions([RawSQL('%d' % (idx + 1), ())])
break
else:
if col_alias:
raise DatabaseError('ORDER BY term does not match any column in the result set.')
# Add column used in ORDER BY clause to the selected
# columns and to each combined query.
order_by_idx = len(self.query.select) + 1
col_name = f'__orderbycol{order_by_idx}'
for q in self.query.combined_queries:
q.add_annotation(expr_src, col_name)
self.query.add_select_col(resolved, col_name)
resolved.set_source_expressions([RawSQL(f'{order_by_idx}', ())])
sql, params = self.compile(resolved)
# Don't add the same column twice, but the order direction is
# not taken into account so we strip it. When this entire method
# is refactored into expressions, then we can check each part as we
# generate it.
without_ordering = self.ordering_parts.search(sql)[1]
params_hash = make_hashable(params)
if (without_ordering, params_hash) in seen:
continue
seen.add((without_ordering, params_hash))
result.append((resolved, (sql, params, is_ref)))
return result
def get_extra_select(self, order_by, select):
extra_select = []
if self.query.distinct and not self.query.distinct_fields:
select_sql = [t[1] for t in select]
for expr, (sql, params, is_ref) in order_by:
without_ordering = self.ordering_parts.search(sql)[1]
if not is_ref and (without_ordering, params) not in select_sql:
extra_select.append((expr, (without_ordering, params), None))
return extra_select
def quote_name_unless_alias(self, name):
"""
A wrapper around connection.ops.quote_name that doesn't quote aliases
for table names. This avoids problems with some SQL dialects that treat
quoted strings specially (e.g. PostgreSQL).
"""
if name in self.quote_cache:
return self.quote_cache[name]
if ((name in self.query.alias_map and name not in self.query.table_map) or
name in self.query.extra_select or (
self.query.external_aliases.get(name) and name not in self.query.table_map)):
self.quote_cache[name] = name
return name
r = self.connection.ops.quote_name(name)
self.quote_cache[name] = r
return r
def compile(self, node):
vendor_impl = getattr(node, 'as_' + self.connection.vendor, None)
if vendor_impl:
sql, params = vendor_impl(self, self.connection)
else:
sql, params = node.as_sql(self, self.connection)
return sql, params
def get_combinator_sql(self, combinator, all):
features = self.connection.features
compilers = [
query.get_compiler(self.using, self.connection, self.elide_empty)
for query in self.query.combined_queries if not query.is_empty()
]
if not features.supports_slicing_ordering_in_compound:
for query, compiler in zip(self.query.combined_queries, compilers):
if query.low_mark or query.high_mark:
raise DatabaseError('LIMIT/OFFSET not allowed in subqueries of compound statements.')
if compiler.get_order_by():
raise DatabaseError('ORDER BY not allowed in subqueries of compound statements.')
parts = ()
for compiler in compilers:
try:
# If the columns list is limited, then all combined queries
# must have the same columns list. Set the selects defined on
# the query on all combined queries, if not already set.
if not compiler.query.values_select and self.query.values_select:
compiler.query = compiler.query.clone()
compiler.query.set_values((
*self.query.extra_select,
*self.query.values_select,
*self.query.annotation_select,
))
part_sql, part_args = compiler.as_sql()
if compiler.query.combinator:
# Wrap in a subquery if wrapping in parentheses isn't
# supported.
if not features.supports_parentheses_in_compound:
part_sql = 'SELECT * FROM ({})'.format(part_sql)
# Add parentheses when combining with compound query if not
# already added for all compound queries.
elif (
self.query.subquery or
not features.supports_slicing_ordering_in_compound
):
part_sql = '({})'.format(part_sql)
parts += ((part_sql, part_args),)
except EmptyResultSet:
# Omit the empty queryset with UNION and with DIFFERENCE if the
# first queryset is nonempty.
if combinator == 'union' or (combinator == 'difference' and parts):
continue
raise
if not parts:
raise EmptyResultSet
combinator_sql = self.connection.ops.set_operators[combinator]
if all and combinator == 'union':
combinator_sql += ' ALL'
braces = '{}'
if not self.query.subquery and features.supports_slicing_ordering_in_compound:
braces = '({})'
sql_parts, args_parts = zip(*((braces.format(sql), args) for sql, args in parts))
result = [' {} '.format(combinator_sql).join(sql_parts)]
params = []
for part in args_parts:
params.extend(part)
return result, params
def as_sql(self, with_limits=True, with_col_aliases=False):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
If 'with_limits' is False, any limit/offset information is not included
in the query.
"""
refcounts_before = self.query.alias_refcount.copy()
try:
extra_select, order_by, group_by = self.pre_sql_setup()
for_update_part = None
# Is a LIMIT/OFFSET clause needed?
with_limit_offset = with_limits and (self.query.high_mark is not None or self.query.low_mark)
combinator = self.query.combinator
features = self.connection.features
if combinator:
if not getattr(features, 'supports_select_{}'.format(combinator)):
raise NotSupportedError('{} is not supported on this database backend.'.format(combinator))
result, params = self.get_combinator_sql(combinator, self.query.combinator_all)
else:
distinct_fields, distinct_params = self.get_distinct()
# This must come after 'select', 'ordering', and 'distinct'
# (see docstring of get_from_clause() for details).
from_, f_params = self.get_from_clause()
try:
where, w_params = self.compile(self.where) if self.where is not None else ('', [])
except EmptyResultSet:
if self.elide_empty:
raise
# Use a predicate that's always False.
where, w_params = '0 = 1', []
having, h_params = self.compile(self.having) if self.having is not None else ("", [])
result = ['SELECT']
params = []
if self.query.distinct:
distinct_result, distinct_params = self.connection.ops.distinct_sql(
distinct_fields,
distinct_params,
)
result += distinct_result
params += distinct_params
out_cols = []
col_idx = 1
for _, (s_sql, s_params), alias in self.select + extra_select:
if alias:
s_sql = '%s AS %s' % (s_sql, self.connection.ops.quote_name(alias))
elif with_col_aliases:
s_sql = '%s AS %s' % (
s_sql,
self.connection.ops.quote_name('col%d' % col_idx),
)
col_idx += 1
params.extend(s_params)
out_cols.append(s_sql)
result += [', '.join(out_cols), 'FROM', *from_]
params.extend(f_params)
if self.query.select_for_update and self.connection.features.has_select_for_update:
if self.connection.get_autocommit():
raise TransactionManagementError('select_for_update cannot be used outside of a transaction.')
if with_limit_offset and not self.connection.features.supports_select_for_update_with_limit:
raise NotSupportedError(
'LIMIT/OFFSET is not supported with '
'select_for_update on this database backend.'
)
nowait = self.query.select_for_update_nowait
skip_locked = self.query.select_for_update_skip_locked
of = self.query.select_for_update_of
no_key = self.query.select_for_no_key_update
# If it's a NOWAIT/SKIP LOCKED/OF/NO KEY query but the
# backend doesn't support it, raise NotSupportedError to
# prevent a possible deadlock.
if nowait and not self.connection.features.has_select_for_update_nowait:
raise NotSupportedError('NOWAIT is not supported on this database backend.')
elif skip_locked and not self.connection.features.has_select_for_update_skip_locked:
raise NotSupportedError('SKIP LOCKED is not supported on this database backend.')
elif of and not self.connection.features.has_select_for_update_of:
raise NotSupportedError('FOR UPDATE OF is not supported on this database backend.')
elif no_key and not self.connection.features.has_select_for_no_key_update:
raise NotSupportedError(
'FOR NO KEY UPDATE is not supported on this '
'database backend.'
)
for_update_part = self.connection.ops.for_update_sql(
nowait=nowait,
skip_locked=skip_locked,
of=self.get_select_for_update_of_arguments(),
no_key=no_key,
)
if for_update_part and self.connection.features.for_update_after_from:
result.append(for_update_part)
if where:
result.append('WHERE %s' % where)
params.extend(w_params)
grouping = []
for g_sql, g_params in group_by:
grouping.append(g_sql)
params.extend(g_params)
if grouping:
if distinct_fields:
raise NotImplementedError('annotate() + distinct(fields) is not implemented.')
order_by = order_by or self.connection.ops.force_no_ordering()
result.append('GROUP BY %s' % ', '.join(grouping))
if self._meta_ordering:
order_by = None
if having:
result.append('HAVING %s' % having)
params.extend(h_params)
if self.query.explain_info:
result.insert(0, self.connection.ops.explain_query_prefix(
self.query.explain_info.format,
**self.query.explain_info.options
))
if order_by:
ordering = []
for _, (o_sql, o_params, _) in order_by:
ordering.append(o_sql)
params.extend(o_params)
result.append('ORDER BY %s' % ', '.join(ordering))
if with_limit_offset:
result.append(self.connection.ops.limit_offset_sql(self.query.low_mark, self.query.high_mark))
if for_update_part and not self.connection.features.for_update_after_from:
result.append(for_update_part)
if self.query.subquery and extra_select:
# If the query is used as a subquery, the extra selects would
# result in more columns than the left-hand side expression is
# expecting. This can happen when a subquery uses a combination
# of order_by() and distinct(), forcing the ordering expressions
# to be selected as well. Wrap the query in another subquery
# to exclude extraneous selects.
sub_selects = []
sub_params = []
for index, (select, _, alias) in enumerate(self.select, start=1):
if not alias and with_col_aliases:
alias = 'col%d' % index
if alias:
sub_selects.append("%s.%s" % (
self.connection.ops.quote_name('subquery'),
self.connection.ops.quote_name(alias),
))
else:
select_clone = select.relabeled_clone({select.alias: 'subquery'})
subselect, subparams = select_clone.as_sql(self, self.connection)
sub_selects.append(subselect)
sub_params.extend(subparams)
return 'SELECT %s FROM (%s) subquery' % (
', '.join(sub_selects),
' '.join(result),
), tuple(sub_params + params)
return ' '.join(result), tuple(params)
finally:
# Finally do cleanup - get rid of the joins we created above.
self.query.reset_refcounts(refcounts_before)
def get_default_columns(self, start_alias=None, opts=None, from_parent=None):
"""
Compute the default columns for selecting every field in the base
model. Will sometimes be called to pull in related models (e.g. via
select_related), in which case "opts" and "start_alias" will be given
to provide a starting point for the traversal.
Return a list of strings, quoted appropriately for use in SQL
directly, as well as a set of aliases used in the select statement (if
'as_pairs' is True, return a list of (alias, col_name) pairs instead
of strings as the first component and None as the second component).
"""
result = []
if opts is None:
opts = self.query.get_meta()
only_load = self.deferred_to_columns()
start_alias = start_alias or self.query.get_initial_alias()
# The 'seen_models' is used to optimize checking the needed parent
# alias for a given field. This also includes None -> start_alias to
# be used by local fields.
seen_models = {None: start_alias}
for field in opts.concrete_fields:
model = field.model._meta.concrete_model
# A proxy model will have a different model and concrete_model. We
# will assign None if the field belongs to this model.
if model == opts.model:
model = None
if from_parent and model is not None and issubclass(
from_parent._meta.concrete_model, model._meta.concrete_model):
# Avoid loading data for already loaded parents.
# We end up here in the case select_related() resolution
# proceeds from parent model to child model. In that case the
# parent model data is already present in the SELECT clause,
# and we want to avoid reloading the same data again.
continue
if field.model in only_load and field.attname not in only_load[field.model]:
continue
alias = self.query.join_parent_model(opts, model, start_alias,
seen_models)
column = field.get_col(alias)
result.append(column)
return result
def get_distinct(self):
"""
Return a quoted list of fields to use in DISTINCT ON part of the query.
This method can alter the tables in the query, and thus it must be
called before get_from_clause().
"""
result = []
params = []
opts = self.query.get_meta()
for name in self.query.distinct_fields:
parts = name.split(LOOKUP_SEP)
_, targets, alias, joins, path, _, transform_function = self._setup_joins(parts, opts, None)
targets, alias, _ = self.query.trim_joins(targets, joins, path)
for target in targets:
if name in self.query.annotation_select:
result.append(self.connection.ops.quote_name(name))
else:
r, p = self.compile(transform_function(target, alias))
result.append(r)
params.append(p)
return result, params
def find_ordering_name(self, name, opts, alias=None, default_order='ASC',
already_seen=None):
"""
Return the table alias (the name might be ambiguous, the alias will
not be) and column name for ordering by the given 'name' parameter.
The 'name' is of the form 'field1__field2__...__fieldN'.
"""
name, order = get_order_dir(name, default_order)
descending = order == 'DESC'
pieces = name.split(LOOKUP_SEP)
field, targets, alias, joins, path, opts, transform_function = self._setup_joins(pieces, opts, alias)
# If we get to this point and the field is a relation to another model,
# append the default ordering for that model unless it is the pk
# shortcut or the attribute name of the field that is specified.
if (
field.is_relation and
opts.ordering and
getattr(field, 'attname', None) != pieces[-1] and
name != 'pk'
):
# Firstly, avoid infinite loops.
already_seen = already_seen or set()
join_tuple = tuple(getattr(self.query.alias_map[j], 'join_cols', None) for j in joins)
if join_tuple in already_seen:
raise FieldError('Infinite loop caused by ordering.')
already_seen.add(join_tuple)
results = []
for item in opts.ordering:
if hasattr(item, 'resolve_expression') and not isinstance(item, OrderBy):
item = item.desc() if descending else item.asc()
if isinstance(item, OrderBy):
results.append((item, False))
continue
results.extend(self.find_ordering_name(item, opts, alias,
order, already_seen))
return results
targets, alias, _ = self.query.trim_joins(targets, joins, path)
return [(OrderBy(transform_function(t, alias), descending=descending), False) for t in targets]
def _setup_joins(self, pieces, opts, alias):
"""
Helper method for get_order_by() and get_distinct().
get_ordering() and get_distinct() must produce same target columns on
same input, as the prefixes of get_ordering() and get_distinct() must
match. Executing SQL where this is not true is an error.
"""
alias = alias or self.query.get_initial_alias()
field, targets, opts, joins, path, transform_function = self.query.setup_joins(pieces, opts, alias)
alias = joins[-1]
return field, targets, alias, joins, path, opts, transform_function
def get_from_clause(self):
"""
Return a list of strings that are joined together to go after the
"FROM" part of the query, as well as a list any extra parameters that
need to be included. Subclasses, can override this to create a
from-clause via a "select".
This should only be called after any SQL construction methods that
might change the tables that are needed. This means the select columns,
ordering, and distinct must be done first.
"""
result = []
params = []
for alias in tuple(self.query.alias_map):
if not self.query.alias_refcount[alias]:
continue
try:
from_clause = self.query.alias_map[alias]
except KeyError:
# Extra tables can end up in self.tables, but not in the
# alias_map if they aren't in a join. That's OK. We skip them.
continue
clause_sql, clause_params = self.compile(from_clause)
result.append(clause_sql)
params.extend(clause_params)
for t in self.query.extra_tables:
alias, _ = self.query.table_alias(t)
# Only add the alias if it's not already present (the table_alias()
# call increments the refcount, so an alias refcount of one means
# this is the only reference).
if alias not in self.query.alias_map or self.query.alias_refcount[alias] == 1:
result.append(', %s' % self.quote_name_unless_alias(alias))
return result, params
def get_related_selections(self, select, opts=None, root_alias=None, cur_depth=1,
requested=None, restricted=None):
"""
Fill in the information needed for a select_related query. The current
depth is measured as the number of connections away from the root model
(for example, cur_depth=1 means we are looking at models with direct
connections to the root model).
"""
def _get_field_choices():
direct_choices = (f.name for f in opts.fields if f.is_relation)
reverse_choices = (
f.field.related_query_name()
for f in opts.related_objects if f.field.unique
)
return chain(direct_choices, reverse_choices, self.query._filtered_relations)
related_klass_infos = []
if not restricted and cur_depth > self.query.max_depth:
# We've recursed far enough; bail out.
return related_klass_infos
if not opts:
opts = self.query.get_meta()
root_alias = self.query.get_initial_alias()
only_load = self.query.get_loaded_field_names()
# Setup for the case when only particular related fields should be
# included in the related selection.
fields_found = set()
if requested is None:
restricted = isinstance(self.query.select_related, dict)
if restricted:
requested = self.query.select_related
def get_related_klass_infos(klass_info, related_klass_infos):
klass_info['related_klass_infos'] = related_klass_infos
for f in opts.fields:
field_model = f.model._meta.concrete_model
fields_found.add(f.name)
if restricted:
next = requested.get(f.name, {})
if not f.is_relation:
# If a non-related field is used like a relation,
# or if a single non-relational field is given.
if next or f.name in requested:
raise FieldError(
"Non-relational field given in select_related: '%s'. "
"Choices are: %s" % (
f.name,
", ".join(_get_field_choices()) or '(none)',
)
)
else:
next = False
if not select_related_descend(f, restricted, requested,
only_load.get(field_model)):
continue
klass_info = {
'model': f.remote_field.model,
'field': f,
'reverse': False,
'local_setter': f.set_cached_value,
'remote_setter': f.remote_field.set_cached_value if f.unique else lambda x, y: None,
'from_parent': False,
}
related_klass_infos.append(klass_info)
select_fields = []
_, _, _, joins, _, _ = self.query.setup_joins(
[f.name], opts, root_alias)
alias = joins[-1]
columns = self.get_default_columns(start_alias=alias, opts=f.remote_field.model._meta)
for col in columns:
select_fields.append(len(select))
select.append((col, None))
klass_info['select_fields'] = select_fields
next_klass_infos = self.get_related_selections(
select, f.remote_field.model._meta, alias, cur_depth + 1, next, restricted)
get_related_klass_infos(klass_info, next_klass_infos)
if restricted:
related_fields = [
(o.field, o.related_model)
for o in opts.related_objects
if o.field.unique and not o.many_to_many
]
for f, model in related_fields:
if not select_related_descend(f, restricted, requested,
only_load.get(model), reverse=True):
continue
related_field_name = f.related_query_name()
fields_found.add(related_field_name)
join_info = self.query.setup_joins([related_field_name], opts, root_alias)
alias = join_info.joins[-1]
from_parent = issubclass(model, opts.model) and model is not opts.model
klass_info = {
'model': model,
'field': f,
'reverse': True,
'local_setter': f.remote_field.set_cached_value,
'remote_setter': f.set_cached_value,
'from_parent': from_parent,
}
related_klass_infos.append(klass_info)
select_fields = []
columns = self.get_default_columns(
start_alias=alias, opts=model._meta, from_parent=opts.model)
for col in columns:
select_fields.append(len(select))
select.append((col, None))
klass_info['select_fields'] = select_fields
next = requested.get(f.related_query_name(), {})
next_klass_infos = self.get_related_selections(
select, model._meta, alias, cur_depth + 1,
next, restricted)
get_related_klass_infos(klass_info, next_klass_infos)
def local_setter(obj, from_obj):
# Set a reverse fk object when relation is non-empty.
if from_obj:
f.remote_field.set_cached_value(from_obj, obj)
def remote_setter(name, obj, from_obj):
setattr(from_obj, name, obj)
for name in list(requested):
# Filtered relations work only on the topmost level.
if cur_depth > 1:
break
if name in self.query._filtered_relations:
fields_found.add(name)
f, _, join_opts, joins, _, _ = self.query.setup_joins([name], opts, root_alias)
model = join_opts.model
alias = joins[-1]
from_parent = issubclass(model, opts.model) and model is not opts.model
klass_info = {
'model': model,
'field': f,
'reverse': True,
'local_setter': local_setter,
'remote_setter': partial(remote_setter, name),
'from_parent': from_parent,
}
related_klass_infos.append(klass_info)
select_fields = []
columns = self.get_default_columns(
start_alias=alias, opts=model._meta,
from_parent=opts.model,
)
for col in columns:
select_fields.append(len(select))
select.append((col, None))
klass_info['select_fields'] = select_fields
next_requested = requested.get(name, {})
next_klass_infos = self.get_related_selections(
select, opts=model._meta, root_alias=alias,
cur_depth=cur_depth + 1, requested=next_requested,
restricted=restricted,
)
get_related_klass_infos(klass_info, next_klass_infos)
fields_not_found = set(requested).difference(fields_found)
if fields_not_found:
invalid_fields = ("'%s'" % s for s in fields_not_found)
raise FieldError(
'Invalid field name(s) given in select_related: %s. '
'Choices are: %s' % (
', '.join(invalid_fields),
', '.join(_get_field_choices()) or '(none)',
)
)
return related_klass_infos
def get_select_for_update_of_arguments(self):
"""
Return a quoted list of arguments for the SELECT FOR UPDATE OF part of
the query.
"""
def _get_parent_klass_info(klass_info):
concrete_model = klass_info['model']._meta.concrete_model
for parent_model, parent_link in concrete_model._meta.parents.items():
parent_list = parent_model._meta.get_parent_list()
yield {
'model': parent_model,
'field': parent_link,
'reverse': False,
'select_fields': [
select_index
for select_index in klass_info['select_fields']
# Selected columns from a model or its parents.
if (
self.select[select_index][0].target.model == parent_model or
self.select[select_index][0].target.model in parent_list
)
],
}
def _get_first_selected_col_from_model(klass_info):
"""
Find the first selected column from a model. If it doesn't exist,
don't lock a model.
select_fields is filled recursively, so it also contains fields
from the parent models.
"""
concrete_model = klass_info['model']._meta.concrete_model
for select_index in klass_info['select_fields']:
if self.select[select_index][0].target.model == concrete_model:
return self.select[select_index][0]
def _get_field_choices():
"""Yield all allowed field paths in breadth-first search order."""
queue = collections.deque([(None, self.klass_info)])
while queue:
parent_path, klass_info = queue.popleft()
if parent_path is None:
path = []
yield 'self'
else:
field = klass_info['field']
if klass_info['reverse']:
field = field.remote_field
path = parent_path + [field.name]
yield LOOKUP_SEP.join(path)
queue.extend(
(path, klass_info)
for klass_info in _get_parent_klass_info(klass_info)
)
queue.extend(
(path, klass_info)
for klass_info in klass_info.get('related_klass_infos', [])
)
if not self.klass_info:
return []
result = []
invalid_names = []
for name in self.query.select_for_update_of:
klass_info = self.klass_info
if name == 'self':
col = _get_first_selected_col_from_model(klass_info)
else:
for part in name.split(LOOKUP_SEP):
klass_infos = (
*klass_info.get('related_klass_infos', []),
*_get_parent_klass_info(klass_info),
)
for related_klass_info in klass_infos:
field = related_klass_info['field']
if related_klass_info['reverse']:
field = field.remote_field
if field.name == part:
klass_info = related_klass_info
break
else:
klass_info = None
break
if klass_info is None:
invalid_names.append(name)
continue
col = _get_first_selected_col_from_model(klass_info)
if col is not None:
if self.connection.features.select_for_update_of_column:
result.append(self.compile(col)[0])
else:
result.append(self.quote_name_unless_alias(col.alias))
if invalid_names:
raise FieldError(
'Invalid field name(s) given in select_for_update(of=(...)): %s. '
'Only relational fields followed in the query are allowed. '
'Choices are: %s.' % (
', '.join(invalid_names),
', '.join(_get_field_choices()),
)
)
return result
def deferred_to_columns(self):
"""
Convert the self.deferred_loading data structure to mapping of table
names to sets of column names which are to be loaded. Return the
dictionary.
"""
columns = {}
self.query.deferred_to_data(columns, self.query.get_loaded_field_names_cb)
return columns
def get_converters(self, expressions):
converters = {}
for i, expression in enumerate(expressions):
if expression:
backend_converters = self.connection.ops.get_db_converters(expression)
field_converters = expression.get_db_converters(self.connection)
if backend_converters or field_converters:
converters[i] = (backend_converters + field_converters, expression)
return converters
def apply_converters(self, rows, converters):
connection = self.connection
converters = list(converters.items())
for row in map(list, rows):
for pos, (convs, expression) in converters:
value = row[pos]
for converter in convs:
value = converter(value, expression, connection)
row[pos] = value
yield row
def results_iter(self, results=None, tuple_expected=False, chunked_fetch=False,
chunk_size=GET_ITERATOR_CHUNK_SIZE):
"""Return an iterator over the results from executing this query."""
if results is None:
results = self.execute_sql(MULTI, chunked_fetch=chunked_fetch, chunk_size=chunk_size)
fields = [s[0] for s in self.select[0:self.col_count]]
converters = self.get_converters(fields)
rows = chain.from_iterable(results)
if converters:
rows = self.apply_converters(rows, converters)
if tuple_expected:
rows = map(tuple, rows)
return rows
def has_results(self):
"""
Backends (e.g. NoSQL) can override this in order to use optimized
versions of "query has any results."
"""
return bool(self.execute_sql(SINGLE))
def execute_sql(self, result_type=MULTI, chunked_fetch=False, chunk_size=GET_ITERATOR_CHUNK_SIZE):
"""
Run the query against the database and return the result(s). The
return value is a single data item if result_type is SINGLE, or an
iterator over the results if the result_type is MULTI.
result_type is either MULTI (use fetchmany() to retrieve all rows),
SINGLE (only retrieve a single row), or None. In this last case, the
cursor is returned if any query is executed, since it's used by
subclasses such as InsertQuery). It's possible, however, that no query
is needed, as the filters describe an empty set. In that case, None is
returned, to avoid any unnecessary database interaction.
"""
result_type = result_type or NO_RESULTS
try:
sql, params = self.as_sql()
if not sql:
raise EmptyResultSet
except EmptyResultSet:
if result_type == MULTI:
return iter([])
else:
return
if chunked_fetch:
cursor = self.connection.chunked_cursor()
else:
cursor = self.connection.cursor()
try:
cursor.execute(sql, params)
except Exception:
# Might fail for server-side cursors (e.g. connection closed)
cursor.close()
raise
if result_type == CURSOR:
# Give the caller the cursor to process and close.
return cursor
if result_type == SINGLE:
try:
val = cursor.fetchone()
if val:
return val[0:self.col_count]
return val
finally:
# done with the cursor
cursor.close()
if result_type == NO_RESULTS:
cursor.close()
return
result = cursor_iter(
cursor, self.connection.features.empty_fetchmany_value,
self.col_count if self.has_extra_select else None,
chunk_size,
)
if not chunked_fetch or not self.connection.features.can_use_chunked_reads:
# If we are using non-chunked reads, we return the same data
# structure as normally, but ensure it is all read into memory
# before going any further. Use chunked_fetch if requested,
# unless the database doesn't support it.
return list(result)
return result
def as_subquery_condition(self, alias, columns, compiler):
qn = compiler.quote_name_unless_alias
qn2 = self.connection.ops.quote_name
for index, select_col in enumerate(self.query.select):
lhs_sql, lhs_params = self.compile(select_col)
rhs = '%s.%s' % (qn(alias), qn2(columns[index]))
self.query.where.add(
RawSQL('%s = %s' % (lhs_sql, rhs), lhs_params), 'AND')
sql, params = self.as_sql()
return 'EXISTS (%s)' % sql, params
def explain_query(self):
result = list(self.execute_sql())
# Some backends return 1 item tuples with strings, and others return
# tuples with integers and strings. Flatten them out into strings.
output_formatter = json.dumps if self.query.explain_info.format == 'json' else str
for row in result[0]:
if not isinstance(row, str):
yield ' '.join(output_formatter(c) for c in row)
else:
yield row
class SQLInsertCompiler(SQLCompiler):
returning_fields = None
returning_params = tuple()
def field_as_sql(self, field, val):
"""
Take a field and a value intended to be saved on that field, and
return placeholder SQL and accompanying params. Check for raw values,
expressions, and fields with get_placeholder() defined in that order.
When field is None, consider the value raw and use it as the
placeholder, with no corresponding parameters returned.
"""
if field is None:
# A field value of None means the value is raw.
sql, params = val, []
elif hasattr(val, 'as_sql'):
# This is an expression, let's compile it.
sql, params = self.compile(val)
elif hasattr(field, 'get_placeholder'):
# Some fields (e.g. geo fields) need special munging before
# they can be inserted.
sql, params = field.get_placeholder(val, self, self.connection), [val]
else:
# Return the common case for the placeholder
sql, params = '%s', [val]
# The following hook is only used by Oracle Spatial, which sometimes
# needs to yield 'NULL' and [] as its placeholder and params instead
# of '%s' and [None]. The 'NULL' placeholder is produced earlier by
# OracleOperations.get_geom_placeholder(). The following line removes
# the corresponding None parameter. See ticket #10888.
params = self.connection.ops.modify_insert_params(sql, params)
return sql, params
def prepare_value(self, field, value):
"""
Prepare a value to be used in a query by resolving it if it is an
expression and otherwise calling the field's get_db_prep_save().
"""
if hasattr(value, 'resolve_expression'):
value = value.resolve_expression(self.query, allow_joins=False, for_save=True)
# Don't allow values containing Col expressions. They refer to
# existing columns on a row, but in the case of insert the row
# doesn't exist yet.
if value.contains_column_references:
raise ValueError(
'Failed to insert expression "%s" on %s. F() expressions '
'can only be used to update, not to insert.' % (value, field)
)
if value.contains_aggregate:
raise FieldError(
'Aggregate functions are not allowed in this query '
'(%s=%r).' % (field.name, value)
)
if value.contains_over_clause:
raise FieldError(
'Window expressions are not allowed in this query (%s=%r).'
% (field.name, value)
)
else:
value = field.get_db_prep_save(value, connection=self.connection)
return value
def pre_save_val(self, field, obj):
"""
Get the given field's value off the given obj. pre_save() is used for
things like auto_now on DateTimeField. Skip it if this is a raw query.
"""
if self.query.raw:
return getattr(obj, field.attname)
return field.pre_save(obj, add=True)
def assemble_as_sql(self, fields, value_rows):
"""
Take a sequence of N fields and a sequence of M rows of values, and
generate placeholder SQL and parameters for each field and value.
Return a pair containing:
* a sequence of M rows of N SQL placeholder strings, and
* a sequence of M rows of corresponding parameter values.
Each placeholder string may contain any number of '%s' interpolation
strings, and each parameter row will contain exactly as many params
as the total number of '%s's in the corresponding placeholder row.
"""
if not value_rows:
return [], []
# list of (sql, [params]) tuples for each object to be saved
# Shape: [n_objs][n_fields][2]
rows_of_fields_as_sql = (
(self.field_as_sql(field, v) for field, v in zip(fields, row))
for row in value_rows
)
# tuple like ([sqls], [[params]s]) for each object to be saved
# Shape: [n_objs][2][n_fields]
sql_and_param_pair_rows = (zip(*row) for row in rows_of_fields_as_sql)
# Extract separate lists for placeholders and params.
# Each of these has shape [n_objs][n_fields]
placeholder_rows, param_rows = zip(*sql_and_param_pair_rows)
# Params for each field are still lists, and need to be flattened.
param_rows = [[p for ps in row for p in ps] for row in param_rows]
return placeholder_rows, param_rows
def as_sql(self):
# We don't need quote_name_unless_alias() here, since these are all
# going to be column names (so we can avoid the extra overhead).
qn = self.connection.ops.quote_name
opts = self.query.get_meta()
insert_statement = self.connection.ops.insert_statement(
on_conflict=self.query.on_conflict,
)
result = ['%s %s' % (insert_statement, qn(opts.db_table))]
fields = self.query.fields or [opts.pk]
result.append('(%s)' % ', '.join(qn(f.column) for f in fields))
if self.query.fields:
value_rows = [
[self.prepare_value(field, self.pre_save_val(field, obj)) for field in fields]
for obj in self.query.objs
]
else:
# An empty object.
value_rows = [[self.connection.ops.pk_default_value()] for _ in self.query.objs]
fields = [None]
# Currently the backends just accept values when generating bulk
# queries and generate their own placeholders. Doing that isn't
# necessary and it should be possible to use placeholders and
# expressions in bulk inserts too.
can_bulk = (not self.returning_fields and self.connection.features.has_bulk_insert)
placeholder_rows, param_rows = self.assemble_as_sql(fields, value_rows)
on_conflict_suffix_sql = self.connection.ops.on_conflict_suffix_sql(
fields,
self.query.on_conflict,
self.query.update_fields,
self.query.unique_fields,
)
if self.returning_fields and self.connection.features.can_return_columns_from_insert:
if self.connection.features.can_return_rows_from_bulk_insert:
result.append(self.connection.ops.bulk_insert_sql(fields, placeholder_rows))
params = param_rows
else:
result.append("VALUES (%s)" % ", ".join(placeholder_rows[0]))
params = [param_rows[0]]
if on_conflict_suffix_sql:
result.append(on_conflict_suffix_sql)
# Skip empty r_sql to allow subclasses to customize behavior for
# 3rd party backends. Refs #19096.
r_sql, self.returning_params = self.connection.ops.return_insert_columns(self.returning_fields)
if r_sql:
result.append(r_sql)
params += [self.returning_params]
return [(" ".join(result), tuple(chain.from_iterable(params)))]
if can_bulk:
result.append(self.connection.ops.bulk_insert_sql(fields, placeholder_rows))
if on_conflict_suffix_sql:
result.append(on_conflict_suffix_sql)
return [(" ".join(result), tuple(p for ps in param_rows for p in ps))]
else:
if on_conflict_suffix_sql:
result.append(on_conflict_suffix_sql)
return [
(" ".join(result + ["VALUES (%s)" % ", ".join(p)]), vals)
for p, vals in zip(placeholder_rows, param_rows)
]
def execute_sql(self, returning_fields=None):
assert not (
returning_fields and len(self.query.objs) != 1 and
not self.connection.features.can_return_rows_from_bulk_insert
)
opts = self.query.get_meta()
self.returning_fields = returning_fields
with self.connection.cursor() as cursor:
for sql, params in self.as_sql():
cursor.execute(sql, params)
if not self.returning_fields:
return []
if self.connection.features.can_return_rows_from_bulk_insert and len(self.query.objs) > 1:
rows = self.connection.ops.fetch_returned_insert_rows(cursor)
elif self.connection.features.can_return_columns_from_insert:
assert len(self.query.objs) == 1
rows = [self.connection.ops.fetch_returned_insert_columns(
cursor, self.returning_params,
)]
else:
rows = [(self.connection.ops.last_insert_id(
cursor, opts.db_table, opts.pk.column,
),)]
cols = [field.get_col(opts.db_table) for field in self.returning_fields]
converters = self.get_converters(cols)
if converters:
rows = list(self.apply_converters(rows, converters))
return rows
class SQLDeleteCompiler(SQLCompiler):
@cached_property
def single_alias(self):
# Ensure base table is in aliases.
self.query.get_initial_alias()
return sum(self.query.alias_refcount[t] > 0 for t in self.query.alias_map) == 1
@classmethod
def _expr_refs_base_model(cls, expr, base_model):
if isinstance(expr, Query):
return expr.model == base_model
if not hasattr(expr, 'get_source_expressions'):
return False
return any(
cls._expr_refs_base_model(source_expr, base_model)
for source_expr in expr.get_source_expressions()
)
@cached_property
def contains_self_reference_subquery(self):
return any(
self._expr_refs_base_model(expr, self.query.model)
for expr in chain(self.query.annotations.values(), self.query.where.children)
)
def _as_sql(self, query):
result = [
'DELETE FROM %s' % self.quote_name_unless_alias(query.base_table)
]
where, params = self.compile(query.where)
if where:
result.append('WHERE %s' % where)
return ' '.join(result), tuple(params)
def as_sql(self):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
"""
if self.single_alias and not self.contains_self_reference_subquery:
return self._as_sql(self.query)
innerq = self.query.clone()
innerq.__class__ = Query
innerq.clear_select_clause()
pk = self.query.model._meta.pk
innerq.select = [
pk.get_col(self.query.get_initial_alias())
]
outerq = Query(self.query.model)
if not self.connection.features.update_can_self_select:
# Force the materialization of the inner query to allow reference
# to the target table on MySQL.
sql, params = innerq.get_compiler(connection=self.connection).as_sql()
innerq = RawSQL('SELECT * FROM (%s) subquery' % sql, params)
outerq.add_filter('pk__in', innerq)
return self._as_sql(outerq)
class SQLUpdateCompiler(SQLCompiler):
def as_sql(self):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
"""
self.pre_sql_setup()
if not self.query.values:
return '', ()
qn = self.quote_name_unless_alias
values, update_params = [], []
for field, model, val in self.query.values:
if hasattr(val, 'resolve_expression'):
val = val.resolve_expression(self.query, allow_joins=False, for_save=True)
if val.contains_aggregate:
raise FieldError(
'Aggregate functions are not allowed in this query '
'(%s=%r).' % (field.name, val)
)
if val.contains_over_clause:
raise FieldError(
'Window expressions are not allowed in this query '
'(%s=%r).' % (field.name, val)
)
elif hasattr(val, 'prepare_database_save'):
if field.remote_field:
val = field.get_db_prep_save(
val.prepare_database_save(field),
connection=self.connection,
)
else:
raise TypeError(
"Tried to update field %s with a model instance, %r. "
"Use a value compatible with %s."
% (field, val, field.__class__.__name__)
)
else:
val = field.get_db_prep_save(val, connection=self.connection)
# Getting the placeholder for the field.
if hasattr(field, 'get_placeholder'):
placeholder = field.get_placeholder(val, self, self.connection)
else:
placeholder = '%s'
name = field.column
if hasattr(val, 'as_sql'):
sql, params = self.compile(val)
values.append('%s = %s' % (qn(name), placeholder % sql))
update_params.extend(params)
elif val is not None:
values.append('%s = %s' % (qn(name), placeholder))
update_params.append(val)
else:
values.append('%s = NULL' % qn(name))
table = self.query.base_table
result = [
'UPDATE %s SET' % qn(table),
', '.join(values),
]
where, params = self.compile(self.query.where)
if where:
result.append('WHERE %s' % where)
return ' '.join(result), tuple(update_params + params)
def execute_sql(self, result_type):
"""
Execute the specified update. Return the number of rows affected by
the primary update query. The "primary update query" is the first
non-empty query that is executed. Row counts for any subsequent,
related queries are not available.
"""
cursor = super().execute_sql(result_type)
try:
rows = cursor.rowcount if cursor else 0
is_empty = cursor is None
finally:
if cursor:
cursor.close()
for query in self.query.get_related_updates():
aux_rows = query.get_compiler(self.using).execute_sql(result_type)
if is_empty and aux_rows:
rows = aux_rows
is_empty = False
return rows
def pre_sql_setup(self):
"""
If the update depends on results from other tables, munge the "where"
conditions to match the format required for (portable) SQL updates.
If multiple updates are required, pull out the id values to update at
this point so that they don't change as a result of the progressive
updates.
"""
refcounts_before = self.query.alias_refcount.copy()
# Ensure base table is in the query
self.query.get_initial_alias()
count = self.query.count_active_tables()
if not self.query.related_updates and count == 1:
return
query = self.query.chain(klass=Query)
query.select_related = False
query.clear_ordering(force=True)
query.extra = {}
query.select = []
query.add_fields([query.get_meta().pk.name])
super().pre_sql_setup()
must_pre_select = count > 1 and not self.connection.features.update_can_self_select
# Now we adjust the current query: reset the where clause and get rid
# of all the tables we don't need (since they're in the sub-select).
self.query.clear_where()
if self.query.related_updates or must_pre_select:
# Either we're using the idents in multiple update queries (so
# don't want them to change), or the db backend doesn't support
# selecting from the updating table (e.g. MySQL).
idents = []
for rows in query.get_compiler(self.using).execute_sql(MULTI):
idents.extend(r[0] for r in rows)
self.query.add_filter('pk__in', idents)
self.query.related_ids = idents
else:
# The fast path. Filters and updates in one query.
self.query.add_filter('pk__in', query)
self.query.reset_refcounts(refcounts_before)
class SQLAggregateCompiler(SQLCompiler):
def as_sql(self):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
"""
sql, params = [], []
for annotation in self.query.annotation_select.values():
ann_sql, ann_params = self.compile(annotation)
ann_sql, ann_params = annotation.select_format(self, ann_sql, ann_params)
sql.append(ann_sql)
params.extend(ann_params)
self.col_count = len(self.query.annotation_select)
sql = ', '.join(sql)
params = tuple(params)
inner_query_sql, inner_query_params = self.query.inner_query.get_compiler(
self.using, elide_empty=self.elide_empty,
).as_sql(with_col_aliases=True)
sql = 'SELECT %s FROM (%s) subquery' % (sql, inner_query_sql)
params = params + inner_query_params
return sql, params
def cursor_iter(cursor, sentinel, col_count, itersize):
"""
Yield blocks of rows from a cursor and ensure the cursor is closed when
done.
"""
try:
for rows in iter((lambda: cursor.fetchmany(itersize)), sentinel):
yield rows if col_count is None else [r[:col_count] for r in rows]
finally:
cursor.close()
|
b8c7dd2d81b8d144aa931a99eb7fce8f34cb1fe1845c6a3dba938ff38a1d5f41 | """
Code to manage the creation and SQL rendering of 'where' constraints.
"""
from django.core.exceptions import EmptyResultSet
from django.utils import tree
from django.utils.functional import cached_property
# Connection types
AND = 'AND'
OR = 'OR'
class WhereNode(tree.Node):
"""
An SQL WHERE clause.
The class is tied to the Query class that created it (in order to create
the correct SQL).
A child is usually an expression producing boolean values. Most likely the
expression is a Lookup instance.
However, a child could also be any class with as_sql() and either
relabeled_clone() method or relabel_aliases() and clone() methods and
contains_aggregate attribute.
"""
default = AND
resolved = False
conditional = True
def split_having(self, negated=False):
"""
Return two possibly None nodes: one for those parts of self that
should be included in the WHERE clause and one for those parts of
self that must be included in the HAVING clause.
"""
if not self.contains_aggregate:
return self, None
in_negated = negated ^ self.negated
# If the effective connector is OR and this node contains an aggregate,
# then we need to push the whole branch to HAVING clause.
may_need_split = (
(in_negated and self.connector == AND) or
(not in_negated and self.connector == OR))
if may_need_split and self.contains_aggregate:
return None, self
where_parts = []
having_parts = []
for c in self.children:
if hasattr(c, 'split_having'):
where_part, having_part = c.split_having(in_negated)
if where_part is not None:
where_parts.append(where_part)
if having_part is not None:
having_parts.append(having_part)
elif c.contains_aggregate:
having_parts.append(c)
else:
where_parts.append(c)
having_node = self.__class__(having_parts, self.connector, self.negated) if having_parts else None
where_node = self.__class__(where_parts, self.connector, self.negated) if where_parts else None
return where_node, having_node
def as_sql(self, compiler, connection):
"""
Return the SQL version of the where clause and the value to be
substituted in. Return '', [] if this node matches everything,
None, [] if this node is empty, and raise EmptyResultSet if this
node can't match anything.
"""
result = []
result_params = []
if self.connector == AND:
full_needed, empty_needed = len(self.children), 1
else:
full_needed, empty_needed = 1, len(self.children)
for child in self.children:
try:
sql, params = compiler.compile(child)
except EmptyResultSet:
empty_needed -= 1
else:
if sql:
result.append(sql)
result_params.extend(params)
else:
full_needed -= 1
# Check if this node matches nothing or everything.
# First check the amount of full nodes and empty nodes
# to make this node empty/full.
# Now, check if this node is full/empty using the
# counts.
if empty_needed == 0:
if self.negated:
return '', []
else:
raise EmptyResultSet
if full_needed == 0:
if self.negated:
raise EmptyResultSet
else:
return '', []
conn = ' %s ' % self.connector
sql_string = conn.join(result)
if sql_string:
if self.negated:
# Some backends (Oracle at least) need parentheses
# around the inner SQL in the negated case, even if the
# inner SQL contains just a single expression.
sql_string = 'NOT (%s)' % sql_string
elif len(result) > 1 or self.resolved:
sql_string = '(%s)' % sql_string
return sql_string, result_params
def get_group_by_cols(self, alias=None):
cols = []
for child in self.children:
cols.extend(child.get_group_by_cols())
return cols
def get_source_expressions(self):
return self.children[:]
def set_source_expressions(self, children):
assert len(children) == len(self.children)
self.children = children
def relabel_aliases(self, change_map):
"""
Relabel the alias values of any children. 'change_map' is a dictionary
mapping old (current) alias values to the new values.
"""
for pos, child in enumerate(self.children):
if hasattr(child, 'relabel_aliases'):
# For example another WhereNode
child.relabel_aliases(change_map)
elif hasattr(child, 'relabeled_clone'):
self.children[pos] = child.relabeled_clone(change_map)
def clone(self):
"""
Create a clone of the tree. Must only be called on root nodes (nodes
with empty subtree_parents). Childs must be either (Constraint, lookup,
value) tuples, or objects supporting .clone().
"""
clone = self.__class__._new_instance(
children=None, connector=self.connector, negated=self.negated,
)
for child in self.children:
if hasattr(child, 'clone'):
clone.children.append(child.clone())
else:
clone.children.append(child)
return clone
def relabeled_clone(self, change_map):
clone = self.clone()
clone.relabel_aliases(change_map)
return clone
def copy(self):
return self.clone()
@classmethod
def _contains_aggregate(cls, obj):
if isinstance(obj, tree.Node):
return any(cls._contains_aggregate(c) for c in obj.children)
return obj.contains_aggregate
@cached_property
def contains_aggregate(self):
return self._contains_aggregate(self)
@classmethod
def _contains_over_clause(cls, obj):
if isinstance(obj, tree.Node):
return any(cls._contains_over_clause(c) for c in obj.children)
return obj.contains_over_clause
@cached_property
def contains_over_clause(self):
return self._contains_over_clause(self)
@staticmethod
def _resolve_leaf(expr, query, *args, **kwargs):
if hasattr(expr, 'resolve_expression'):
expr = expr.resolve_expression(query, *args, **kwargs)
return expr
@classmethod
def _resolve_node(cls, node, query, *args, **kwargs):
if hasattr(node, 'children'):
for child in node.children:
cls._resolve_node(child, query, *args, **kwargs)
if hasattr(node, 'lhs'):
node.lhs = cls._resolve_leaf(node.lhs, query, *args, **kwargs)
if hasattr(node, 'rhs'):
node.rhs = cls._resolve_leaf(node.rhs, query, *args, **kwargs)
def resolve_expression(self, *args, **kwargs):
clone = self.clone()
clone._resolve_node(clone, *args, **kwargs)
clone.resolved = True
return clone
@cached_property
def output_field(self):
from django.db.models import BooleanField
return BooleanField()
def select_format(self, compiler, sql, params):
# Wrap filters with a CASE WHEN expression if a database backend
# (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
# BY list.
if not compiler.connection.features.supports_boolean_expr_in_select_clause:
sql = f'CASE WHEN {sql} THEN 1 ELSE 0 END'
return sql, params
def get_db_converters(self, connection):
return self.output_field.get_db_converters(connection)
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
class NothingNode:
"""A node that matches nothing."""
contains_aggregate = False
def as_sql(self, compiler=None, connection=None):
raise EmptyResultSet
class ExtraWhere:
# The contents are a black box - assume no aggregates are used.
contains_aggregate = False
def __init__(self, sqls, params):
self.sqls = sqls
self.params = params
def as_sql(self, compiler=None, connection=None):
sqls = ["(%s)" % sql for sql in self.sqls]
return " AND ".join(sqls), list(self.params or ())
class SubqueryConstraint:
# Even if aggregates would be used in a subquery, the outer query isn't
# interested about those.
contains_aggregate = False
def __init__(self, alias, columns, targets, query_object):
self.alias = alias
self.columns = columns
self.targets = targets
query_object.clear_ordering(clear_default=True)
self.query_object = query_object
def as_sql(self, compiler, connection):
query = self.query_object
query.set_values(self.targets)
query_compiler = query.get_compiler(connection=connection)
return query_compiler.as_subquery_condition(self.alias, self.columns, compiler)
|
f4855f322f7baa241ea5a9df05c6cfcfbb629216e8277e151502219d4f809ac1 | """
Query subclasses which provide extra functionality beyond simple data retrieval.
"""
from django.core.exceptions import FieldError
from django.db.models.sql.constants import (
CURSOR, GET_ITERATOR_CHUNK_SIZE, NO_RESULTS,
)
from django.db.models.sql.query import Query
__all__ = ['DeleteQuery', 'UpdateQuery', 'InsertQuery', 'AggregateQuery']
class DeleteQuery(Query):
"""A DELETE SQL query."""
compiler = 'SQLDeleteCompiler'
def do_query(self, table, where, using):
self.alias_map = {table: self.alias_map[table]}
self.where = where
cursor = self.get_compiler(using).execute_sql(CURSOR)
if cursor:
with cursor:
return cursor.rowcount
return 0
def delete_batch(self, pk_list, using):
"""
Set up and execute delete queries for all the objects in pk_list.
More than one physical query may be executed if there are a
lot of values in pk_list.
"""
# number of objects deleted
num_deleted = 0
field = self.get_meta().pk
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
self.clear_where()
self.add_filter(
f'{field.attname}__in',
pk_list[offset:offset + GET_ITERATOR_CHUNK_SIZE],
)
num_deleted += self.do_query(self.get_meta().db_table, self.where, using=using)
return num_deleted
class UpdateQuery(Query):
"""An UPDATE SQL query."""
compiler = 'SQLUpdateCompiler'
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self._setup_query()
def _setup_query(self):
"""
Run on initialization and at the end of chaining. Any attributes that
would normally be set in __init__() should go here instead.
"""
self.values = []
self.related_ids = None
self.related_updates = {}
def clone(self):
obj = super().clone()
obj.related_updates = self.related_updates.copy()
return obj
def update_batch(self, pk_list, values, using):
self.add_update_values(values)
for offset in range(0, len(pk_list), GET_ITERATOR_CHUNK_SIZE):
self.clear_where()
self.add_filter('pk__in', pk_list[offset: offset + GET_ITERATOR_CHUNK_SIZE])
self.get_compiler(using).execute_sql(NO_RESULTS)
def add_update_values(self, values):
"""
Convert a dictionary of field name to value mappings into an update
query. This is the entry point for the public update() method on
querysets.
"""
values_seq = []
for name, val in values.items():
field = self.get_meta().get_field(name)
direct = not (field.auto_created and not field.concrete) or not field.concrete
model = field.model._meta.concrete_model
if not direct or (field.is_relation and field.many_to_many):
raise FieldError(
'Cannot update model field %r (only non-relations and '
'foreign keys permitted).' % field
)
if model is not self.get_meta().concrete_model:
self.add_related_update(model, field, val)
continue
values_seq.append((field, model, val))
return self.add_update_fields(values_seq)
def add_update_fields(self, values_seq):
"""
Append a sequence of (field, model, value) triples to the internal list
that will be used to generate the UPDATE query. Might be more usefully
called add_update_targets() to hint at the extra information here.
"""
for field, model, val in values_seq:
if hasattr(val, 'resolve_expression'):
# Resolve expressions here so that annotations are no longer needed
val = val.resolve_expression(self, allow_joins=False, for_save=True)
self.values.append((field, model, val))
def add_related_update(self, model, field, value):
"""
Add (name, value) to an update query for an ancestor model.
Update are coalesced so that only one update query per ancestor is run.
"""
self.related_updates.setdefault(model, []).append((field, None, value))
def get_related_updates(self):
"""
Return a list of query objects: one for each update required to an
ancestor model. Each query will have the same filtering conditions as
the current query but will only update a single table.
"""
if not self.related_updates:
return []
result = []
for model, values in self.related_updates.items():
query = UpdateQuery(model)
query.values = values
if self.related_ids is not None:
query.add_filter('pk__in', self.related_ids)
result.append(query)
return result
class InsertQuery(Query):
compiler = 'SQLInsertCompiler'
def __init__(self, *args, on_conflict=None, update_fields=None, unique_fields=None, **kwargs):
super().__init__(*args, **kwargs)
self.fields = []
self.objs = []
self.on_conflict = on_conflict
self.update_fields = update_fields or []
self.unique_fields = unique_fields or []
def insert_values(self, fields, objs, raw=False):
self.fields = fields
self.objs = objs
self.raw = raw
class AggregateQuery(Query):
"""
Take another query as a parameter to the FROM clause and only select the
elements in the provided list.
"""
compiler = 'SQLAggregateCompiler'
def __init__(self, model, inner_query):
self.inner_query = inner_query
super().__init__(model)
|
e214e8ac2f90607efbfbdad7e64a89075974279b1ac00f599ffdd5a43a00d837 | from django.db import DatabaseError, InterfaceError
from django.db.backends.base.features import BaseDatabaseFeatures
from django.utils.functional import cached_property
class DatabaseFeatures(BaseDatabaseFeatures):
# Oracle crashes with "ORA-00932: inconsistent datatypes: expected - got
# BLOB" when grouping by LOBs (#24096).
allows_group_by_lob = False
interprets_empty_strings_as_nulls = True
has_select_for_update = True
has_select_for_update_nowait = True
has_select_for_update_skip_locked = True
has_select_for_update_of = True
select_for_update_of_column = True
can_return_columns_from_insert = True
supports_subqueries_in_group_by = False
ignores_unnecessary_order_by_in_subqueries = False
supports_transactions = True
supports_timezones = False
has_native_duration_field = True
can_defer_constraint_checks = True
supports_partially_nullable_unique_constraints = False
supports_deferrable_unique_constraints = True
truncates_names = True
supports_tablespaces = True
supports_sequence_reset = False
can_introspect_materialized_views = True
atomic_transactions = False
nulls_order_largest = True
requires_literal_defaults = True
closed_cursor_error_class = InterfaceError
bare_select_suffix = " FROM DUAL"
# select for update with limit can be achieved on Oracle, but not with the current backend.
supports_select_for_update_with_limit = False
supports_temporal_subtraction = True
# Oracle doesn't ignore quoted identifiers case but the current backend
# does by uppercasing all identifiers.
ignores_table_name_case = True
supports_index_on_text_field = False
create_test_procedure_without_params_sql = """
CREATE PROCEDURE "TEST_PROCEDURE" AS
V_I INTEGER;
BEGIN
V_I := 1;
END;
"""
create_test_procedure_with_int_param_sql = """
CREATE PROCEDURE "TEST_PROCEDURE" (P_I INTEGER) AS
V_I INTEGER;
BEGIN
V_I := P_I;
END;
"""
supports_callproc_kwargs = True
supports_over_clause = True
supports_frame_range_fixed_distance = True
supports_ignore_conflicts = False
max_query_params = 2**16 - 1
supports_partial_indexes = False
supports_slicing_ordering_in_compound = True
allows_multiple_constraints_on_same_fields = False
supports_boolean_expr_in_select_clause = False
supports_primitives_in_json_field = False
supports_json_field_contains = False
supports_collation_on_textfield = False
test_collations = {
'ci': 'BINARY_CI',
'cs': 'BINARY',
'non_default': 'SWEDISH_CI',
'swedish_ci': 'SWEDISH_CI',
}
test_now_utc_template = "CURRENT_TIMESTAMP AT TIME ZONE 'UTC'"
django_test_skips = {
"Oracle doesn't support SHA224.": {
'db_functions.text.test_sha224.SHA224Tests.test_basic',
'db_functions.text.test_sha224.SHA224Tests.test_transform',
},
"Oracle doesn't correctly calculate ISO 8601 week numbering before "
"1583 (the Gregorian calendar was introduced in 1582).": {
'db_functions.datetime.test_extract_trunc.DateFunctionTests.test_trunc_week_before_1000',
'db_functions.datetime.test_extract_trunc.DateFunctionWithTimeZoneTests.test_trunc_week_before_1000',
},
"Oracle doesn't support bitwise XOR.": {
'expressions.tests.ExpressionOperatorTests.test_lefthand_bitwise_xor',
'expressions.tests.ExpressionOperatorTests.test_lefthand_bitwise_xor_null',
'expressions.tests.ExpressionOperatorTests.test_lefthand_bitwise_xor_right_null',
},
"Oracle requires ORDER BY in row_number, ANSI:SQL doesn't.": {
'expressions_window.tests.WindowFunctionTests.test_row_number_no_ordering',
},
'Raises ORA-00600: internal error code.': {
'model_fields.test_jsonfield.TestQuerying.test_usage_in_subquery',
},
}
django_test_expected_failures = {
# A bug in Django/cx_Oracle with respect to string handling (#23843).
'annotations.tests.NonAggregateAnnotationTestCase.test_custom_functions',
'annotations.tests.NonAggregateAnnotationTestCase.test_custom_functions_can_ref_other_functions',
}
@cached_property
def introspected_field_types(self):
return {
**super().introspected_field_types,
'GenericIPAddressField': 'CharField',
'PositiveBigIntegerField': 'BigIntegerField',
'PositiveIntegerField': 'IntegerField',
'PositiveSmallIntegerField': 'IntegerField',
'SmallIntegerField': 'IntegerField',
'TimeField': 'DateTimeField',
}
@cached_property
def supports_collation_on_charfield(self):
with self.connection.cursor() as cursor:
try:
cursor.execute("SELECT CAST('a' AS VARCHAR2(4001)) FROM dual")
except DatabaseError as e:
if e.args[0].code == 910:
return False
raise
return True
|
01c2fcadf1160c391a19e106a6b44aec5e4f0a145ed69c63a80a70c84ef71bca | from collections import namedtuple
import cx_Oracle
from django.db import models
from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo as BaseFieldInfo, TableInfo,
)
from django.utils.functional import cached_property
FieldInfo = namedtuple('FieldInfo', BaseFieldInfo._fields + ('is_autofield', 'is_json'))
class DatabaseIntrospection(BaseDatabaseIntrospection):
cache_bust_counter = 1
# Maps type objects to Django Field types.
@cached_property
def data_types_reverse(self):
if self.connection.cx_oracle_version < (8,):
return {
cx_Oracle.BLOB: 'BinaryField',
cx_Oracle.CLOB: 'TextField',
cx_Oracle.DATETIME: 'DateField',
cx_Oracle.FIXED_CHAR: 'CharField',
cx_Oracle.FIXED_NCHAR: 'CharField',
cx_Oracle.INTERVAL: 'DurationField',
cx_Oracle.NATIVE_FLOAT: 'FloatField',
cx_Oracle.NCHAR: 'CharField',
cx_Oracle.NCLOB: 'TextField',
cx_Oracle.NUMBER: 'DecimalField',
cx_Oracle.STRING: 'CharField',
cx_Oracle.TIMESTAMP: 'DateTimeField',
}
else:
return {
cx_Oracle.DB_TYPE_DATE: 'DateField',
cx_Oracle.DB_TYPE_BINARY_DOUBLE: 'FloatField',
cx_Oracle.DB_TYPE_BLOB: 'BinaryField',
cx_Oracle.DB_TYPE_CHAR: 'CharField',
cx_Oracle.DB_TYPE_CLOB: 'TextField',
cx_Oracle.DB_TYPE_INTERVAL_DS: 'DurationField',
cx_Oracle.DB_TYPE_NCHAR: 'CharField',
cx_Oracle.DB_TYPE_NCLOB: 'TextField',
cx_Oracle.DB_TYPE_NVARCHAR: 'CharField',
cx_Oracle.DB_TYPE_NUMBER: 'DecimalField',
cx_Oracle.DB_TYPE_TIMESTAMP: 'DateTimeField',
cx_Oracle.DB_TYPE_VARCHAR: 'CharField',
}
def get_field_type(self, data_type, description):
if data_type == cx_Oracle.NUMBER:
precision, scale = description[4:6]
if scale == 0:
if precision > 11:
return 'BigAutoField' if description.is_autofield else 'BigIntegerField'
elif 1 < precision < 6 and description.is_autofield:
return 'SmallAutoField'
elif precision == 1:
return 'BooleanField'
elif description.is_autofield:
return 'AutoField'
else:
return 'IntegerField'
elif scale == -127:
return 'FloatField'
elif data_type == cx_Oracle.NCLOB and description.is_json:
return 'JSONField'
return super().get_field_type(data_type, description)
def get_table_list(self, cursor):
"""Return a list of table and view names in the current database."""
cursor.execute("""
SELECT table_name, 't'
FROM user_tables
WHERE
NOT EXISTS (
SELECT 1
FROM user_mviews
WHERE user_mviews.mview_name = user_tables.table_name
)
UNION ALL
SELECT view_name, 'v' FROM user_views
UNION ALL
SELECT mview_name, 'v' FROM user_mviews
""")
return [TableInfo(self.identifier_converter(row[0]), row[1]) for row in cursor.fetchall()]
def get_table_description(self, cursor, table_name):
"""
Return a description of the table with the DB-API cursor.description
interface.
"""
# user_tab_columns gives data default for columns
cursor.execute("""
SELECT
user_tab_cols.column_name,
user_tab_cols.data_default,
CASE
WHEN user_tab_cols.collation = user_tables.default_collation
THEN NULL
ELSE user_tab_cols.collation
END collation,
CASE
WHEN user_tab_cols.char_used IS NULL
THEN user_tab_cols.data_length
ELSE user_tab_cols.char_length
END as internal_size,
CASE
WHEN user_tab_cols.identity_column = 'YES' THEN 1
ELSE 0
END as is_autofield,
CASE
WHEN EXISTS (
SELECT 1
FROM user_json_columns
WHERE
user_json_columns.table_name = user_tab_cols.table_name AND
user_json_columns.column_name = user_tab_cols.column_name
)
THEN 1
ELSE 0
END as is_json
FROM user_tab_cols
LEFT OUTER JOIN
user_tables ON user_tables.table_name = user_tab_cols.table_name
WHERE user_tab_cols.table_name = UPPER(%s)
""", [table_name])
field_map = {
column: (internal_size, default if default != 'NULL' else None, collation, is_autofield, is_json)
for column, default, collation, internal_size, is_autofield, is_json in cursor.fetchall()
}
self.cache_bust_counter += 1
cursor.execute("SELECT * FROM {} WHERE ROWNUM < 2 AND {} > 0".format(
self.connection.ops.quote_name(table_name),
self.cache_bust_counter))
description = []
for desc in cursor.description:
name = desc[0]
internal_size, default, collation, is_autofield, is_json = field_map[name]
name = name % {} # cx_Oracle, for some reason, doubles percent signs.
description.append(FieldInfo(
self.identifier_converter(name), *desc[1:3], internal_size, desc[4] or 0,
desc[5] or 0, *desc[6:], default, collation, is_autofield, is_json,
))
return description
def identifier_converter(self, name):
"""Identifier comparison is case insensitive under Oracle."""
return name.lower()
def get_sequences(self, cursor, table_name, table_fields=()):
cursor.execute("""
SELECT
user_tab_identity_cols.sequence_name,
user_tab_identity_cols.column_name
FROM
user_tab_identity_cols,
user_constraints,
user_cons_columns cols
WHERE
user_constraints.constraint_name = cols.constraint_name
AND user_constraints.table_name = user_tab_identity_cols.table_name
AND cols.column_name = user_tab_identity_cols.column_name
AND user_constraints.constraint_type = 'P'
AND user_tab_identity_cols.table_name = UPPER(%s)
""", [table_name])
# Oracle allows only one identity column per table.
row = cursor.fetchone()
if row:
return [{
'name': self.identifier_converter(row[0]),
'table': self.identifier_converter(table_name),
'column': self.identifier_converter(row[1]),
}]
# To keep backward compatibility for AutoFields that aren't Oracle
# identity columns.
for f in table_fields:
if isinstance(f, models.AutoField):
return [{'table': table_name, 'column': f.column}]
return []
def get_relations(self, cursor, table_name):
"""
Return a dictionary of {field_name: (field_name_other_table, other_table)}
representing all foreign keys in the given table.
"""
table_name = table_name.upper()
cursor.execute("""
SELECT ca.column_name, cb.table_name, cb.column_name
FROM user_constraints, USER_CONS_COLUMNS ca, USER_CONS_COLUMNS cb
WHERE user_constraints.table_name = %s AND
user_constraints.constraint_name = ca.constraint_name AND
user_constraints.r_constraint_name = cb.constraint_name AND
ca.position = cb.position""", [table_name])
return {
self.identifier_converter(field_name): (
self.identifier_converter(rel_field_name),
self.identifier_converter(rel_table_name),
) for field_name, rel_table_name, rel_field_name in cursor.fetchall()
}
def get_primary_key_column(self, cursor, table_name):
cursor.execute("""
SELECT
cols.column_name
FROM
user_constraints,
user_cons_columns cols
WHERE
user_constraints.constraint_name = cols.constraint_name AND
user_constraints.constraint_type = 'P' AND
user_constraints.table_name = UPPER(%s) AND
cols.position = 1
""", [table_name])
row = cursor.fetchone()
return self.identifier_converter(row[0]) if row else None
def get_constraints(self, cursor, table_name):
"""
Retrieve any constraints or keys (unique, pk, fk, check, index) across
one or more columns.
"""
constraints = {}
# Loop over the constraints, getting PKs, uniques, and checks
cursor.execute("""
SELECT
user_constraints.constraint_name,
LISTAGG(LOWER(cols.column_name), ',') WITHIN GROUP (ORDER BY cols.position),
CASE user_constraints.constraint_type
WHEN 'P' THEN 1
ELSE 0
END AS is_primary_key,
CASE
WHEN user_constraints.constraint_type IN ('P', 'U') THEN 1
ELSE 0
END AS is_unique,
CASE user_constraints.constraint_type
WHEN 'C' THEN 1
ELSE 0
END AS is_check_constraint
FROM
user_constraints
LEFT OUTER JOIN
user_cons_columns cols ON user_constraints.constraint_name = cols.constraint_name
WHERE
user_constraints.constraint_type = ANY('P', 'U', 'C')
AND user_constraints.table_name = UPPER(%s)
GROUP BY user_constraints.constraint_name, user_constraints.constraint_type
""", [table_name])
for constraint, columns, pk, unique, check in cursor.fetchall():
constraint = self.identifier_converter(constraint)
constraints[constraint] = {
'columns': columns.split(','),
'primary_key': pk,
'unique': unique,
'foreign_key': None,
'check': check,
'index': unique, # All uniques come with an index
}
# Foreign key constraints
cursor.execute("""
SELECT
cons.constraint_name,
LISTAGG(LOWER(cols.column_name), ',') WITHIN GROUP (ORDER BY cols.position),
LOWER(rcols.table_name),
LOWER(rcols.column_name)
FROM
user_constraints cons
INNER JOIN
user_cons_columns rcols ON rcols.constraint_name = cons.r_constraint_name AND rcols.position = 1
LEFT OUTER JOIN
user_cons_columns cols ON cons.constraint_name = cols.constraint_name
WHERE
cons.constraint_type = 'R' AND
cons.table_name = UPPER(%s)
GROUP BY cons.constraint_name, rcols.table_name, rcols.column_name
""", [table_name])
for constraint, columns, other_table, other_column in cursor.fetchall():
constraint = self.identifier_converter(constraint)
constraints[constraint] = {
'primary_key': False,
'unique': False,
'foreign_key': (other_table, other_column),
'check': False,
'index': False,
'columns': columns.split(','),
}
# Now get indexes
cursor.execute("""
SELECT
ind.index_name,
LOWER(ind.index_type),
LOWER(ind.uniqueness),
LISTAGG(LOWER(cols.column_name), ',') WITHIN GROUP (ORDER BY cols.column_position),
LISTAGG(cols.descend, ',') WITHIN GROUP (ORDER BY cols.column_position)
FROM
user_ind_columns cols, user_indexes ind
WHERE
cols.table_name = UPPER(%s) AND
NOT EXISTS (
SELECT 1
FROM user_constraints cons
WHERE ind.index_name = cons.index_name
) AND cols.index_name = ind.index_name
GROUP BY ind.index_name, ind.index_type, ind.uniqueness
""", [table_name])
for constraint, type_, unique, columns, orders in cursor.fetchall():
constraint = self.identifier_converter(constraint)
constraints[constraint] = {
'primary_key': False,
'unique': unique == 'unique',
'foreign_key': None,
'check': False,
'index': True,
'type': 'idx' if type_ == 'normal' else type_,
'columns': columns.split(','),
'orders': orders.split(','),
}
return constraints
|
1bac3fca285d88c6ae74a7c6f0b1e7f0938d5cfa3dbc3bcd6aa9f4f70614ae3e | import datetime
import uuid
from functools import lru_cache
from django.conf import settings
from django.db import DatabaseError, NotSupportedError
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.backends.utils import (
split_tzname_delta, strip_quotes, truncate_name,
)
from django.db.models import AutoField, Exists, ExpressionWrapper, Lookup
from django.db.models.expressions import RawSQL
from django.db.models.sql.where import WhereNode
from django.utils import timezone
from django.utils.encoding import force_bytes, force_str
from django.utils.functional import cached_property
from django.utils.regex_helper import _lazy_re_compile
from .base import Database
from .utils import BulkInsertMapper, InsertVar, Oracle_datetime
class DatabaseOperations(BaseDatabaseOperations):
# Oracle uses NUMBER(5), NUMBER(11), and NUMBER(19) for integer fields.
# SmallIntegerField uses NUMBER(11) instead of NUMBER(5), which is used by
# SmallAutoField, to preserve backward compatibility.
integer_field_ranges = {
'SmallIntegerField': (-99999999999, 99999999999),
'IntegerField': (-99999999999, 99999999999),
'BigIntegerField': (-9999999999999999999, 9999999999999999999),
'PositiveBigIntegerField': (0, 9999999999999999999),
'PositiveSmallIntegerField': (0, 99999999999),
'PositiveIntegerField': (0, 99999999999),
'SmallAutoField': (-99999, 99999),
'AutoField': (-99999999999, 99999999999),
'BigAutoField': (-9999999999999999999, 9999999999999999999),
}
set_operators = {**BaseDatabaseOperations.set_operators, 'difference': 'MINUS'}
# TODO: colorize this SQL code with style.SQL_KEYWORD(), etc.
_sequence_reset_sql = """
DECLARE
table_value integer;
seq_value integer;
seq_name user_tab_identity_cols.sequence_name%%TYPE;
BEGIN
BEGIN
SELECT sequence_name INTO seq_name FROM user_tab_identity_cols
WHERE table_name = '%(table_name)s' AND
column_name = '%(column_name)s';
EXCEPTION WHEN NO_DATA_FOUND THEN
seq_name := '%(no_autofield_sequence_name)s';
END;
SELECT NVL(MAX(%(column)s), 0) INTO table_value FROM %(table)s;
SELECT NVL(last_number - cache_size, 0) INTO seq_value FROM user_sequences
WHERE sequence_name = seq_name;
WHILE table_value > seq_value LOOP
EXECUTE IMMEDIATE 'SELECT "'||seq_name||'".nextval FROM DUAL'
INTO seq_value;
END LOOP;
END;
/"""
# Oracle doesn't support string without precision; use the max string size.
cast_char_field_without_max_length = 'NVARCHAR2(2000)'
cast_data_types = {
'AutoField': 'NUMBER(11)',
'BigAutoField': 'NUMBER(19)',
'SmallAutoField': 'NUMBER(5)',
'TextField': cast_char_field_without_max_length,
}
def cache_key_culling_sql(self):
cache_key = self.quote_name('cache_key')
return (
f'SELECT {cache_key} '
f'FROM %s '
f'ORDER BY {cache_key} OFFSET %%s ROWS FETCH FIRST 1 ROWS ONLY'
)
def date_extract_sql(self, lookup_type, field_name):
if lookup_type == 'week_day':
# TO_CHAR(field, 'D') returns an integer from 1-7, where 1=Sunday.
return "TO_CHAR(%s, 'D')" % field_name
elif lookup_type == 'iso_week_day':
return "TO_CHAR(%s - 1, 'D')" % field_name
elif lookup_type == 'week':
# IW = ISO week number
return "TO_CHAR(%s, 'IW')" % field_name
elif lookup_type == 'quarter':
return "TO_CHAR(%s, 'Q')" % field_name
elif lookup_type == 'iso_year':
return "TO_CHAR(%s, 'IYYY')" % field_name
else:
# https://docs.oracle.com/en/database/oracle/oracle-database/18/sqlrf/EXTRACT-datetime.html
return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), field_name)
def date_trunc_sql(self, lookup_type, field_name, tzname=None):
field_name = self._convert_field_to_tz(field_name, tzname)
# https://docs.oracle.com/en/database/oracle/oracle-database/18/sqlrf/ROUND-and-TRUNC-Date-Functions.html
if lookup_type in ('year', 'month'):
return "TRUNC(%s, '%s')" % (field_name, lookup_type.upper())
elif lookup_type == 'quarter':
return "TRUNC(%s, 'Q')" % field_name
elif lookup_type == 'week':
return "TRUNC(%s, 'IW')" % field_name
else:
return "TRUNC(%s)" % field_name
# Oracle crashes with "ORA-03113: end-of-file on communication channel"
# if the time zone name is passed in parameter. Use interpolation instead.
# https://groups.google.com/forum/#!msg/django-developers/zwQju7hbG78/9l934yelwfsJ
# This regexp matches all time zone names from the zoneinfo database.
_tzname_re = _lazy_re_compile(r'^[\w/:+-]+$')
def _prepare_tzname_delta(self, tzname):
tzname, sign, offset = split_tzname_delta(tzname)
return f'{sign}{offset}' if offset else tzname
def _convert_field_to_tz(self, field_name, tzname):
if not (settings.USE_TZ and tzname):
return field_name
if not self._tzname_re.match(tzname):
raise ValueError("Invalid time zone name: %s" % tzname)
# Convert from connection timezone to the local time, returning
# TIMESTAMP WITH TIME ZONE and cast it back to TIMESTAMP to strip the
# TIME ZONE details.
if self.connection.timezone_name != tzname:
return "CAST((FROM_TZ(%s, '%s') AT TIME ZONE '%s') AS TIMESTAMP)" % (
field_name,
self.connection.timezone_name,
self._prepare_tzname_delta(tzname),
)
return field_name
def datetime_cast_date_sql(self, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return 'TRUNC(%s)' % field_name
def datetime_cast_time_sql(self, field_name, tzname):
# Since `TimeField` values are stored as TIMESTAMP change to the
# default date and convert the field to the specified timezone.
convert_datetime_sql = (
"TO_TIMESTAMP(CONCAT('1900-01-01 ', TO_CHAR(%s, 'HH24:MI:SS.FF')), "
"'YYYY-MM-DD HH24:MI:SS.FF')"
) % self._convert_field_to_tz(field_name, tzname)
return "CASE WHEN %s IS NOT NULL THEN %s ELSE NULL END" % (
field_name, convert_datetime_sql,
)
def datetime_extract_sql(self, lookup_type, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return self.date_extract_sql(lookup_type, field_name)
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
# https://docs.oracle.com/en/database/oracle/oracle-database/18/sqlrf/ROUND-and-TRUNC-Date-Functions.html
if lookup_type in ('year', 'month'):
sql = "TRUNC(%s, '%s')" % (field_name, lookup_type.upper())
elif lookup_type == 'quarter':
sql = "TRUNC(%s, 'Q')" % field_name
elif lookup_type == 'week':
sql = "TRUNC(%s, 'IW')" % field_name
elif lookup_type == 'day':
sql = "TRUNC(%s)" % field_name
elif lookup_type == 'hour':
sql = "TRUNC(%s, 'HH24')" % field_name
elif lookup_type == 'minute':
sql = "TRUNC(%s, 'MI')" % field_name
else:
sql = "CAST(%s AS DATE)" % field_name # Cast to DATE removes sub-second precision.
return sql
def time_trunc_sql(self, lookup_type, field_name, tzname=None):
# The implementation is similar to `datetime_trunc_sql` as both
# `DateTimeField` and `TimeField` are stored as TIMESTAMP where
# the date part of the later is ignored.
field_name = self._convert_field_to_tz(field_name, tzname)
if lookup_type == 'hour':
sql = "TRUNC(%s, 'HH24')" % field_name
elif lookup_type == 'minute':
sql = "TRUNC(%s, 'MI')" % field_name
elif lookup_type == 'second':
sql = "CAST(%s AS DATE)" % field_name # Cast to DATE removes sub-second precision.
return sql
def get_db_converters(self, expression):
converters = super().get_db_converters(expression)
internal_type = expression.output_field.get_internal_type()
if internal_type in ['JSONField', 'TextField']:
converters.append(self.convert_textfield_value)
elif internal_type == 'BinaryField':
converters.append(self.convert_binaryfield_value)
elif internal_type == 'BooleanField':
converters.append(self.convert_booleanfield_value)
elif internal_type == 'DateTimeField':
if settings.USE_TZ:
converters.append(self.convert_datetimefield_value)
elif internal_type == 'DateField':
converters.append(self.convert_datefield_value)
elif internal_type == 'TimeField':
converters.append(self.convert_timefield_value)
elif internal_type == 'UUIDField':
converters.append(self.convert_uuidfield_value)
# Oracle stores empty strings as null. If the field accepts the empty
# string, undo this to adhere to the Django convention of using
# the empty string instead of null.
if expression.output_field.empty_strings_allowed:
converters.append(
self.convert_empty_bytes
if internal_type == 'BinaryField' else
self.convert_empty_string
)
return converters
def convert_textfield_value(self, value, expression, connection):
if isinstance(value, Database.LOB):
value = value.read()
return value
def convert_binaryfield_value(self, value, expression, connection):
if isinstance(value, Database.LOB):
value = force_bytes(value.read())
return value
def convert_booleanfield_value(self, value, expression, connection):
if value in (0, 1):
value = bool(value)
return value
# cx_Oracle always returns datetime.datetime objects for
# DATE and TIMESTAMP columns, but Django wants to see a
# python datetime.date, .time, or .datetime.
def convert_datetimefield_value(self, value, expression, connection):
if value is not None:
value = timezone.make_aware(value, self.connection.timezone)
return value
def convert_datefield_value(self, value, expression, connection):
if isinstance(value, Database.Timestamp):
value = value.date()
return value
def convert_timefield_value(self, value, expression, connection):
if isinstance(value, Database.Timestamp):
value = value.time()
return value
def convert_uuidfield_value(self, value, expression, connection):
if value is not None:
value = uuid.UUID(value)
return value
@staticmethod
def convert_empty_string(value, expression, connection):
return '' if value is None else value
@staticmethod
def convert_empty_bytes(value, expression, connection):
return b'' if value is None else value
def deferrable_sql(self):
return " DEFERRABLE INITIALLY DEFERRED"
def fetch_returned_insert_columns(self, cursor, returning_params):
columns = []
for param in returning_params:
value = param.get_value()
if value == []:
raise DatabaseError(
'The database did not return a new row id. Probably '
'"ORA-1403: no data found" was raised internally but was '
'hidden by the Oracle OCI library (see '
'https://code.djangoproject.com/ticket/28859).'
)
columns.append(value[0])
return tuple(columns)
def field_cast_sql(self, db_type, internal_type):
if db_type and db_type.endswith('LOB') and internal_type != 'JSONField':
return "DBMS_LOB.SUBSTR(%s)"
else:
return "%s"
def no_limit_value(self):
return None
def limit_offset_sql(self, low_mark, high_mark):
fetch, offset = self._get_limit_offset_params(low_mark, high_mark)
return ' '.join(sql for sql in (
('OFFSET %d ROWS' % offset) if offset else None,
('FETCH FIRST %d ROWS ONLY' % fetch) if fetch else None,
) if sql)
def last_executed_query(self, cursor, sql, params):
# https://cx-oracle.readthedocs.io/en/latest/api_manual/cursor.html#Cursor.statement
# The DB API definition does not define this attribute.
statement = cursor.statement
# Unlike Psycopg's `query` and MySQLdb`'s `_executed`, cx_Oracle's
# `statement` doesn't contain the query parameters. Substitute
# parameters manually.
if isinstance(params, (tuple, list)):
for i, param in enumerate(params):
statement = statement.replace(':arg%d' % i, force_str(param, errors='replace'))
elif isinstance(params, dict):
for key, param in params.items():
statement = statement.replace(':%s' % key, force_str(param, errors='replace'))
return statement
def last_insert_id(self, cursor, table_name, pk_name):
sq_name = self._get_sequence_name(cursor, strip_quotes(table_name), pk_name)
cursor.execute('"%s".currval' % sq_name)
return cursor.fetchone()[0]
def lookup_cast(self, lookup_type, internal_type=None):
if lookup_type in ('iexact', 'icontains', 'istartswith', 'iendswith'):
return "UPPER(%s)"
if internal_type == 'JSONField' and lookup_type == 'exact':
return 'DBMS_LOB.SUBSTR(%s)'
return "%s"
def max_in_list_size(self):
return 1000
def max_name_length(self):
return 30
def pk_default_value(self):
return "NULL"
def prep_for_iexact_query(self, x):
return x
def process_clob(self, value):
if value is None:
return ''
return value.read()
def quote_name(self, name):
# SQL92 requires delimited (quoted) names to be case-sensitive. When
# not quoted, Oracle has case-insensitive behavior for identifiers, but
# always defaults to uppercase.
# We simplify things by making Oracle identifiers always uppercase.
if not name.startswith('"') and not name.endswith('"'):
name = '"%s"' % truncate_name(name, self.max_name_length())
# Oracle puts the query text into a (query % args) construct, so % signs
# in names need to be escaped. The '%%' will be collapsed back to '%' at
# that stage so we aren't really making the name longer here.
name = name.replace('%', '%%')
return name.upper()
def regex_lookup(self, lookup_type):
if lookup_type == 'regex':
match_option = "'c'"
else:
match_option = "'i'"
return 'REGEXP_LIKE(%%s, %%s, %s)' % match_option
def return_insert_columns(self, fields):
if not fields:
return '', ()
field_names = []
params = []
for field in fields:
field_names.append('%s.%s' % (
self.quote_name(field.model._meta.db_table),
self.quote_name(field.column),
))
params.append(InsertVar(field))
return 'RETURNING %s INTO %s' % (
', '.join(field_names),
', '.join(['%s'] * len(params)),
), tuple(params)
def __foreign_key_constraints(self, table_name, recursive):
with self.connection.cursor() as cursor:
if recursive:
cursor.execute("""
SELECT
user_tables.table_name, rcons.constraint_name
FROM
user_tables
JOIN
user_constraints cons
ON (user_tables.table_name = cons.table_name AND cons.constraint_type = ANY('P', 'U'))
LEFT JOIN
user_constraints rcons
ON (user_tables.table_name = rcons.table_name AND rcons.constraint_type = 'R')
START WITH user_tables.table_name = UPPER(%s)
CONNECT BY NOCYCLE PRIOR cons.constraint_name = rcons.r_constraint_name
GROUP BY
user_tables.table_name, rcons.constraint_name
HAVING user_tables.table_name != UPPER(%s)
ORDER BY MAX(level) DESC
""", (table_name, table_name))
else:
cursor.execute("""
SELECT
cons.table_name, cons.constraint_name
FROM
user_constraints cons
WHERE
cons.constraint_type = 'R'
AND cons.table_name = UPPER(%s)
""", (table_name,))
return cursor.fetchall()
@cached_property
def _foreign_key_constraints(self):
# 512 is large enough to fit the ~330 tables (as of this writing) in
# Django's test suite.
return lru_cache(maxsize=512)(self.__foreign_key_constraints)
def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):
if not tables:
return []
truncated_tables = {table.upper() for table in tables}
constraints = set()
# Oracle's TRUNCATE CASCADE only works with ON DELETE CASCADE foreign
# keys which Django doesn't define. Emulate the PostgreSQL behavior
# which truncates all dependent tables by manually retrieving all
# foreign key constraints and resolving dependencies.
for table in tables:
for foreign_table, constraint in self._foreign_key_constraints(table, recursive=allow_cascade):
if allow_cascade:
truncated_tables.add(foreign_table)
constraints.add((foreign_table, constraint))
sql = [
'%s %s %s %s %s %s %s %s;' % (
style.SQL_KEYWORD('ALTER'),
style.SQL_KEYWORD('TABLE'),
style.SQL_FIELD(self.quote_name(table)),
style.SQL_KEYWORD('DISABLE'),
style.SQL_KEYWORD('CONSTRAINT'),
style.SQL_FIELD(self.quote_name(constraint)),
style.SQL_KEYWORD('KEEP'),
style.SQL_KEYWORD('INDEX'),
) for table, constraint in constraints
] + [
'%s %s %s;' % (
style.SQL_KEYWORD('TRUNCATE'),
style.SQL_KEYWORD('TABLE'),
style.SQL_FIELD(self.quote_name(table)),
) for table in truncated_tables
] + [
'%s %s %s %s %s %s;' % (
style.SQL_KEYWORD('ALTER'),
style.SQL_KEYWORD('TABLE'),
style.SQL_FIELD(self.quote_name(table)),
style.SQL_KEYWORD('ENABLE'),
style.SQL_KEYWORD('CONSTRAINT'),
style.SQL_FIELD(self.quote_name(constraint)),
) for table, constraint in constraints
]
if reset_sequences:
sequences = [
sequence
for sequence in self.connection.introspection.sequence_list()
if sequence['table'].upper() in truncated_tables
]
# Since we've just deleted all the rows, running our sequence ALTER
# code will reset the sequence to 0.
sql.extend(self.sequence_reset_by_name_sql(style, sequences))
return sql
def sequence_reset_by_name_sql(self, style, sequences):
sql = []
for sequence_info in sequences:
no_autofield_sequence_name = self._get_no_autofield_sequence_name(sequence_info['table'])
table = self.quote_name(sequence_info['table'])
column = self.quote_name(sequence_info['column'] or 'id')
query = self._sequence_reset_sql % {
'no_autofield_sequence_name': no_autofield_sequence_name,
'table': table,
'column': column,
'table_name': strip_quotes(table),
'column_name': strip_quotes(column),
}
sql.append(query)
return sql
def sequence_reset_sql(self, style, model_list):
output = []
query = self._sequence_reset_sql
for model in model_list:
for f in model._meta.local_fields:
if isinstance(f, AutoField):
no_autofield_sequence_name = self._get_no_autofield_sequence_name(model._meta.db_table)
table = self.quote_name(model._meta.db_table)
column = self.quote_name(f.column)
output.append(query % {
'no_autofield_sequence_name': no_autofield_sequence_name,
'table': table,
'column': column,
'table_name': strip_quotes(table),
'column_name': strip_quotes(column),
})
# Only one AutoField is allowed per model, so don't
# continue to loop
break
return output
def start_transaction_sql(self):
return ''
def tablespace_sql(self, tablespace, inline=False):
if inline:
return "USING INDEX TABLESPACE %s" % self.quote_name(tablespace)
else:
return "TABLESPACE %s" % self.quote_name(tablespace)
def adapt_datefield_value(self, value):
"""
Transform a date value to an object compatible with what is expected
by the backend driver for date columns.
The default implementation transforms the date to text, but that is not
necessary for Oracle.
"""
return value
def adapt_datetimefield_value(self, value):
"""
Transform a datetime value to an object compatible with what is expected
by the backend driver for datetime columns.
If naive datetime is passed assumes that is in UTC. Normally Django
models.DateTimeField makes sure that if USE_TZ is True passed datetime
is timezone aware.
"""
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
# cx_Oracle doesn't support tz-aware datetimes
if timezone.is_aware(value):
if settings.USE_TZ:
value = timezone.make_naive(value, self.connection.timezone)
else:
raise ValueError("Oracle backend does not support timezone-aware datetimes when USE_TZ is False.")
return Oracle_datetime.from_datetime(value)
def adapt_timefield_value(self, value):
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
if isinstance(value, str):
return datetime.datetime.strptime(value, '%H:%M:%S')
# Oracle doesn't support tz-aware times
if timezone.is_aware(value):
raise ValueError("Oracle backend does not support timezone-aware times.")
return Oracle_datetime(1900, 1, 1, value.hour, value.minute,
value.second, value.microsecond)
def adapt_decimalfield_value(self, value, max_digits=None, decimal_places=None):
return value
def combine_expression(self, connector, sub_expressions):
lhs, rhs = sub_expressions
if connector == '%%':
return 'MOD(%s)' % ','.join(sub_expressions)
elif connector == '&':
return 'BITAND(%s)' % ','.join(sub_expressions)
elif connector == '|':
return 'BITAND(-%(lhs)s-1,%(rhs)s)+%(lhs)s' % {'lhs': lhs, 'rhs': rhs}
elif connector == '<<':
return '(%(lhs)s * POWER(2, %(rhs)s))' % {'lhs': lhs, 'rhs': rhs}
elif connector == '>>':
return 'FLOOR(%(lhs)s / POWER(2, %(rhs)s))' % {'lhs': lhs, 'rhs': rhs}
elif connector == '^':
return 'POWER(%s)' % ','.join(sub_expressions)
elif connector == '#':
raise NotSupportedError('Bitwise XOR is not supported in Oracle.')
return super().combine_expression(connector, sub_expressions)
def _get_no_autofield_sequence_name(self, table):
"""
Manually created sequence name to keep backward compatibility for
AutoFields that aren't Oracle identity columns.
"""
name_length = self.max_name_length() - 3
return '%s_SQ' % truncate_name(strip_quotes(table), name_length).upper()
def _get_sequence_name(self, cursor, table, pk_name):
cursor.execute("""
SELECT sequence_name
FROM user_tab_identity_cols
WHERE table_name = UPPER(%s)
AND column_name = UPPER(%s)""", [table, pk_name])
row = cursor.fetchone()
return self._get_no_autofield_sequence_name(table) if row is None else row[0]
def bulk_insert_sql(self, fields, placeholder_rows):
query = []
for row in placeholder_rows:
select = []
for i, placeholder in enumerate(row):
# A model without any fields has fields=[None].
if fields[i]:
internal_type = getattr(fields[i], 'target_field', fields[i]).get_internal_type()
placeholder = BulkInsertMapper.types.get(internal_type, '%s') % placeholder
# Add columns aliases to the first select to avoid "ORA-00918:
# column ambiguously defined" when two or more columns in the
# first select have the same value.
if not query:
placeholder = '%s col_%s' % (placeholder, i)
select.append(placeholder)
query.append('SELECT %s FROM DUAL' % ', '.join(select))
# Bulk insert to tables with Oracle identity columns causes Oracle to
# add sequence.nextval to it. Sequence.nextval cannot be used with the
# UNION operator. To prevent incorrect SQL, move UNION to a subquery.
return 'SELECT * FROM (%s)' % ' UNION ALL '.join(query)
def subtract_temporals(self, internal_type, lhs, rhs):
if internal_type == 'DateField':
lhs_sql, lhs_params = lhs
rhs_sql, rhs_params = rhs
params = (*lhs_params, *rhs_params)
return "NUMTODSINTERVAL(TO_NUMBER(%s - %s), 'DAY')" % (lhs_sql, rhs_sql), params
return super().subtract_temporals(internal_type, lhs, rhs)
def bulk_batch_size(self, fields, objs):
"""Oracle restricts the number of parameters in a query."""
if fields:
return self.connection.features.max_query_params // len(fields)
return len(objs)
def conditional_expression_supported_in_where_clause(self, expression):
"""
Oracle supports only EXISTS(...) or filters in the WHERE clause, others
must be compared with True.
"""
if isinstance(expression, (Exists, Lookup, WhereNode)):
return True
if isinstance(expression, ExpressionWrapper) and expression.conditional:
return self.conditional_expression_supported_in_where_clause(expression.expression)
if isinstance(expression, RawSQL) and expression.conditional:
return True
return False
|
523d31207cace63567bd02d91139f3efc57eaca0e758d7fc0a077e142caa7f54 | import copy
import datetime
import re
from django.db import DatabaseError
from django.db.backends.base.schema import (
BaseDatabaseSchemaEditor, _related_non_m2m_objects,
)
from django.utils.duration import duration_iso_string
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
sql_create_column = "ALTER TABLE %(table)s ADD %(column)s %(definition)s"
sql_alter_column_type = "MODIFY %(column)s %(type)s"
sql_alter_column_null = "MODIFY %(column)s NULL"
sql_alter_column_not_null = "MODIFY %(column)s NOT NULL"
sql_alter_column_default = "MODIFY %(column)s DEFAULT %(default)s"
sql_alter_column_no_default = "MODIFY %(column)s DEFAULT NULL"
sql_alter_column_no_default_null = sql_alter_column_no_default
sql_alter_column_collate = "MODIFY %(column)s %(type)s%(collation)s"
sql_delete_column = "ALTER TABLE %(table)s DROP COLUMN %(column)s"
sql_create_column_inline_fk = 'CONSTRAINT %(name)s REFERENCES %(to_table)s(%(to_column)s)%(deferrable)s'
sql_delete_table = "DROP TABLE %(table)s CASCADE CONSTRAINTS"
sql_create_index = "CREATE INDEX %(name)s ON %(table)s (%(columns)s)%(extra)s"
def quote_value(self, value):
if isinstance(value, (datetime.date, datetime.time, datetime.datetime)):
return "'%s'" % value
elif isinstance(value, datetime.timedelta):
return "'%s'" % duration_iso_string(value)
elif isinstance(value, str):
return "'%s'" % value.replace("\'", "\'\'").replace('%', '%%')
elif isinstance(value, (bytes, bytearray, memoryview)):
return "'%s'" % value.hex()
elif isinstance(value, bool):
return "1" if value else "0"
else:
return str(value)
def remove_field(self, model, field):
# If the column is an identity column, drop the identity before
# removing the field.
if self._is_identity_column(model._meta.db_table, field.column):
self._drop_identity(model._meta.db_table, field.column)
super().remove_field(model, field)
def delete_model(self, model):
# Run superclass action
super().delete_model(model)
# Clean up manually created sequence.
self.execute("""
DECLARE
i INTEGER;
BEGIN
SELECT COUNT(1) INTO i FROM USER_SEQUENCES
WHERE SEQUENCE_NAME = '%(sq_name)s';
IF i = 1 THEN
EXECUTE IMMEDIATE 'DROP SEQUENCE "%(sq_name)s"';
END IF;
END;
/""" % {'sq_name': self.connection.ops._get_no_autofield_sequence_name(model._meta.db_table)})
def alter_field(self, model, old_field, new_field, strict=False):
try:
super().alter_field(model, old_field, new_field, strict)
except DatabaseError as e:
description = str(e)
# If we're changing type to an unsupported type we need a
# SQLite-ish workaround
if 'ORA-22858' in description or 'ORA-22859' in description:
self._alter_field_type_workaround(model, old_field, new_field)
# If an identity column is changing to a non-numeric type, drop the
# identity first.
elif 'ORA-30675' in description:
self._drop_identity(model._meta.db_table, old_field.column)
self.alter_field(model, old_field, new_field, strict)
# If a primary key column is changing to an identity column, drop
# the primary key first.
elif 'ORA-30673' in description and old_field.primary_key:
self._delete_primary_key(model, strict=True)
self._alter_field_type_workaround(model, old_field, new_field)
else:
raise
def _alter_field_type_workaround(self, model, old_field, new_field):
"""
Oracle refuses to change from some type to other type.
What we need to do instead is:
- Add a nullable version of the desired field with a temporary name. If
the new column is an auto field, then the temporary column can't be
nullable.
- Update the table to transfer values from old to new
- Drop old column
- Rename the new column and possibly drop the nullable property
"""
# Make a new field that's like the new one but with a temporary
# column name.
new_temp_field = copy.deepcopy(new_field)
new_temp_field.null = (new_field.get_internal_type() not in ('AutoField', 'BigAutoField', 'SmallAutoField'))
new_temp_field.column = self._generate_temp_name(new_field.column)
# Add it
self.add_field(model, new_temp_field)
# Explicit data type conversion
# https://docs.oracle.com/en/database/oracle/oracle-database/18/sqlrf
# /Data-Type-Comparison-Rules.html#GUID-D0C5A47E-6F93-4C2D-9E49-4F2B86B359DD
new_value = self.quote_name(old_field.column)
old_type = old_field.db_type(self.connection)
if re.match('^N?CLOB', old_type):
new_value = "TO_CHAR(%s)" % new_value
old_type = 'VARCHAR2'
if re.match('^N?VARCHAR2', old_type):
new_internal_type = new_field.get_internal_type()
if new_internal_type == 'DateField':
new_value = "TO_DATE(%s, 'YYYY-MM-DD')" % new_value
elif new_internal_type == 'DateTimeField':
new_value = "TO_TIMESTAMP(%s, 'YYYY-MM-DD HH24:MI:SS.FF')" % new_value
elif new_internal_type == 'TimeField':
# TimeField are stored as TIMESTAMP with a 1900-01-01 date part.
new_value = "TO_TIMESTAMP(CONCAT('1900-01-01 ', %s), 'YYYY-MM-DD HH24:MI:SS.FF')" % new_value
# Transfer values across
self.execute("UPDATE %s set %s=%s" % (
self.quote_name(model._meta.db_table),
self.quote_name(new_temp_field.column),
new_value,
))
# Drop the old field
self.remove_field(model, old_field)
# Rename and possibly make the new field NOT NULL
super().alter_field(model, new_temp_field, new_field)
# Recreate foreign key (if necessary) because the old field is not
# passed to the alter_field() and data types of new_temp_field and
# new_field always match.
new_type = new_field.db_type(self.connection)
if (
(old_field.primary_key and new_field.primary_key) or
(old_field.unique and new_field.unique)
) and old_type != new_type:
for _, rel in _related_non_m2m_objects(new_temp_field, new_field):
if rel.field.db_constraint:
self.execute(self._create_fk_sql(rel.related_model, rel.field, '_fk'))
def _alter_column_type_sql(self, model, old_field, new_field, new_type):
auto_field_types = {'AutoField', 'BigAutoField', 'SmallAutoField'}
# Drop the identity if migrating away from AutoField.
if (
old_field.get_internal_type() in auto_field_types and
new_field.get_internal_type() not in auto_field_types and
self._is_identity_column(model._meta.db_table, new_field.column)
):
self._drop_identity(model._meta.db_table, new_field.column)
return super()._alter_column_type_sql(model, old_field, new_field, new_type)
def normalize_name(self, name):
"""
Get the properly shortened and uppercased identifier as returned by
quote_name() but without the quotes.
"""
nn = self.quote_name(name)
if nn[0] == '"' and nn[-1] == '"':
nn = nn[1:-1]
return nn
def _generate_temp_name(self, for_name):
"""Generate temporary names for workarounds that need temp columns."""
suffix = hex(hash(for_name)).upper()[1:]
return self.normalize_name(for_name + "_" + suffix)
def prepare_default(self, value):
return self.quote_value(value)
def _field_should_be_indexed(self, model, field):
create_index = super()._field_should_be_indexed(model, field)
db_type = field.db_type(self.connection)
if db_type is not None and db_type.lower() in self.connection._limited_data_types:
return False
return create_index
def _is_identity_column(self, table_name, column_name):
with self.connection.cursor() as cursor:
cursor.execute("""
SELECT
CASE WHEN identity_column = 'YES' THEN 1 ELSE 0 END
FROM user_tab_cols
WHERE table_name = %s AND
column_name = %s
""", [self.normalize_name(table_name), self.normalize_name(column_name)])
row = cursor.fetchone()
return row[0] if row else False
def _drop_identity(self, table_name, column_name):
self.execute('ALTER TABLE %(table)s MODIFY %(column)s DROP IDENTITY' % {
'table': self.quote_name(table_name),
'column': self.quote_name(column_name),
})
def _get_default_collation(self, table_name):
with self.connection.cursor() as cursor:
cursor.execute("""
SELECT default_collation FROM user_tables WHERE table_name = %s
""", [self.normalize_name(table_name)])
return cursor.fetchone()[0]
def _alter_column_collation_sql(self, model, new_field, new_type, new_collation):
if new_collation is None:
new_collation = self._get_default_collation(model._meta.db_table)
return super()._alter_column_collation_sql(model, new_field, new_type, new_collation)
|
10b2af0475172d50932f4723d61294c0bd9a15a94f8e69932ab718b4f62e667a | import datetime
from .base import Database
class InsertVar:
"""
A late-binding cursor variable that can be passed to Cursor.execute
as a parameter, in order to receive the id of the row created by an
insert statement.
"""
types = {
'AutoField': int,
'BigAutoField': int,
'SmallAutoField': int,
'IntegerField': int,
'BigIntegerField': int,
'SmallIntegerField': int,
'PositiveBigIntegerField': int,
'PositiveSmallIntegerField': int,
'PositiveIntegerField': int,
'FloatField': Database.NATIVE_FLOAT,
'DateTimeField': Database.TIMESTAMP,
'DateField': Database.Date,
'DecimalField': Database.NUMBER,
}
def __init__(self, field):
internal_type = getattr(field, 'target_field', field).get_internal_type()
self.db_type = self.types.get(internal_type, str)
self.bound_param = None
def bind_parameter(self, cursor):
self.bound_param = cursor.cursor.var(self.db_type)
return self.bound_param
def get_value(self):
return self.bound_param.getvalue()
class Oracle_datetime(datetime.datetime):
"""
A datetime object, with an additional class attribute
to tell cx_Oracle to save the microseconds too.
"""
input_size = Database.TIMESTAMP
@classmethod
def from_datetime(cls, dt):
return Oracle_datetime(
dt.year, dt.month, dt.day,
dt.hour, dt.minute, dt.second, dt.microsecond,
)
class BulkInsertMapper:
BLOB = 'TO_BLOB(%s)'
DATE = 'TO_DATE(%s)'
INTERVAL = 'CAST(%s as INTERVAL DAY(9) TO SECOND(6))'
NCLOB = 'TO_NCLOB(%s)'
NUMBER = 'TO_NUMBER(%s)'
TIMESTAMP = 'TO_TIMESTAMP(%s)'
types = {
'AutoField': NUMBER,
'BigAutoField': NUMBER,
'BigIntegerField': NUMBER,
'BinaryField': BLOB,
'BooleanField': NUMBER,
'DateField': DATE,
'DateTimeField': TIMESTAMP,
'DecimalField': NUMBER,
'DurationField': INTERVAL,
'FloatField': NUMBER,
'IntegerField': NUMBER,
'PositiveBigIntegerField': NUMBER,
'PositiveIntegerField': NUMBER,
'PositiveSmallIntegerField': NUMBER,
'SmallAutoField': NUMBER,
'SmallIntegerField': NUMBER,
'TextField': NCLOB,
'TimeField': TIMESTAMP,
}
def dsn(settings_dict):
if settings_dict['PORT']:
host = settings_dict['HOST'].strip() or 'localhost'
return Database.makedsn(host, int(settings_dict['PORT']), settings_dict['NAME'])
return settings_dict['NAME']
|
526a800e778b5707559d354e24de2a24b2293b8dc1e498cef9f361e7b6953e90 | from django.db import ProgrammingError
from django.utils.functional import cached_property
class BaseDatabaseFeatures:
gis_enabled = False
# Oracle can't group by LOB (large object) data types.
allows_group_by_lob = True
allows_group_by_pk = False
allows_group_by_selected_pks = False
empty_fetchmany_value = []
update_can_self_select = True
# Does the backend distinguish between '' and None?
interprets_empty_strings_as_nulls = False
# Does the backend allow inserting duplicate NULL rows in a nullable
# unique field? All core backends implement this correctly, but other
# databases such as SQL Server do not.
supports_nullable_unique_constraints = True
# Does the backend allow inserting duplicate rows when a unique_together
# constraint exists and some fields are nullable but not all of them?
supports_partially_nullable_unique_constraints = True
# Does the backend support initially deferrable unique constraints?
supports_deferrable_unique_constraints = False
can_use_chunked_reads = True
can_return_columns_from_insert = False
can_return_rows_from_bulk_insert = False
has_bulk_insert = True
uses_savepoints = True
can_release_savepoints = False
# If True, don't use integer foreign keys referring to, e.g., positive
# integer primary keys.
related_fields_match_type = False
allow_sliced_subqueries_with_in = True
has_select_for_update = False
has_select_for_update_nowait = False
has_select_for_update_skip_locked = False
has_select_for_update_of = False
has_select_for_no_key_update = False
# Does the database's SELECT FOR UPDATE OF syntax require a column rather
# than a table?
select_for_update_of_column = False
# Does the default test database allow multiple connections?
# Usually an indication that the test database is in-memory
test_db_allows_multiple_connections = True
# Can an object be saved without an explicit primary key?
supports_unspecified_pk = False
# Can a fixture contain forward references? i.e., are
# FK constraints checked at the end of transaction, or
# at the end of each save operation?
supports_forward_references = True
# Does the backend truncate names properly when they are too long?
truncates_names = False
# Is there a REAL datatype in addition to floats/doubles?
has_real_datatype = False
supports_subqueries_in_group_by = True
# Does the backend ignore unnecessary ORDER BY clauses in subqueries?
ignores_unnecessary_order_by_in_subqueries = True
# Is there a true datatype for uuid?
has_native_uuid_field = False
# Is there a true datatype for timedeltas?
has_native_duration_field = False
# Does the database driver supports same type temporal data subtraction
# by returning the type used to store duration field?
supports_temporal_subtraction = False
# Does the __regex lookup support backreferencing and grouping?
supports_regex_backreferencing = True
# Can date/datetime lookups be performed using a string?
supports_date_lookup_using_string = True
# Can datetimes with timezones be used?
supports_timezones = True
# Does the database have a copy of the zoneinfo database?
has_zoneinfo_database = True
# When performing a GROUP BY, is an ORDER BY NULL required
# to remove any ordering?
requires_explicit_null_ordering_when_grouping = False
# Does the backend order NULL values as largest or smallest?
nulls_order_largest = False
# Does the backend support NULLS FIRST and NULLS LAST in ORDER BY?
supports_order_by_nulls_modifier = True
# Does the backend orders NULLS FIRST by default?
order_by_nulls_first = False
# The database's limit on the number of query parameters.
max_query_params = None
# Can an object have an autoincrement primary key of 0?
allows_auto_pk_0 = True
# Do we need to NULL a ForeignKey out, or can the constraint check be
# deferred
can_defer_constraint_checks = False
# Does the backend support tablespaces? Default to False because it isn't
# in the SQL standard.
supports_tablespaces = False
# Does the backend reset sequences between tests?
supports_sequence_reset = True
# Can the backend introspect the default value of a column?
can_introspect_default = True
# Confirm support for introspected foreign keys
# Every database can do this reliably, except MySQL,
# which can't do it for MyISAM tables
can_introspect_foreign_keys = True
# Map fields which some backends may not be able to differentiate to the
# field it's introspected as.
introspected_field_types = {
'AutoField': 'AutoField',
'BigAutoField': 'BigAutoField',
'BigIntegerField': 'BigIntegerField',
'BinaryField': 'BinaryField',
'BooleanField': 'BooleanField',
'CharField': 'CharField',
'DurationField': 'DurationField',
'GenericIPAddressField': 'GenericIPAddressField',
'IntegerField': 'IntegerField',
'PositiveBigIntegerField': 'PositiveBigIntegerField',
'PositiveIntegerField': 'PositiveIntegerField',
'PositiveSmallIntegerField': 'PositiveSmallIntegerField',
'SmallAutoField': 'SmallAutoField',
'SmallIntegerField': 'SmallIntegerField',
'TimeField': 'TimeField',
}
# Can the backend introspect the column order (ASC/DESC) for indexes?
supports_index_column_ordering = True
# Does the backend support introspection of materialized views?
can_introspect_materialized_views = False
# Support for the DISTINCT ON clause
can_distinct_on_fields = False
# Does the backend prevent running SQL queries in broken transactions?
atomic_transactions = True
# Can we roll back DDL in a transaction?
can_rollback_ddl = False
# Does it support operations requiring references rename in a transaction?
supports_atomic_references_rename = True
# Can we issue more than one ALTER COLUMN clause in an ALTER TABLE?
supports_combined_alters = False
# Does it support foreign keys?
supports_foreign_keys = True
# Can it create foreign key constraints inline when adding columns?
can_create_inline_fk = True
# Does it automatically index foreign keys?
indexes_foreign_keys = True
# Does it support CHECK constraints?
supports_column_check_constraints = True
supports_table_check_constraints = True
# Does the backend support introspection of CHECK constraints?
can_introspect_check_constraints = True
# Does the backend support 'pyformat' style ("... %(name)s ...", {'name': value})
# parameter passing? Note this can be provided by the backend even if not
# supported by the Python driver
supports_paramstyle_pyformat = True
# Does the backend require literal defaults, rather than parameterized ones?
requires_literal_defaults = False
# Does the backend require a connection reset after each material schema change?
connection_persists_old_columns = False
# What kind of error does the backend throw when accessing closed cursor?
closed_cursor_error_class = ProgrammingError
# Does 'a' LIKE 'A' match?
has_case_insensitive_like = False
# Suffix for backends that don't support "SELECT xxx;" queries.
bare_select_suffix = ''
# If NULL is implied on columns without needing to be explicitly specified
implied_column_null = False
# Does the backend support "select for update" queries with limit (and offset)?
supports_select_for_update_with_limit = True
# Does the backend ignore null expressions in GREATEST and LEAST queries unless
# every expression is null?
greatest_least_ignores_nulls = False
# Can the backend clone databases for parallel test execution?
# Defaults to False to allow third-party backends to opt-in.
can_clone_databases = False
# Does the backend consider table names with different casing to
# be equal?
ignores_table_name_case = False
# Place FOR UPDATE right after FROM clause. Used on MSSQL.
for_update_after_from = False
# Combinatorial flags
supports_select_union = True
supports_select_intersection = True
supports_select_difference = True
supports_slicing_ordering_in_compound = False
supports_parentheses_in_compound = True
# Does the database support SQL 2003 FILTER (WHERE ...) in aggregate
# expressions?
supports_aggregate_filter_clause = False
# Does the backend support indexing a TextField?
supports_index_on_text_field = True
# Does the backend support window expressions (expression OVER (...))?
supports_over_clause = False
supports_frame_range_fixed_distance = False
only_supports_unbounded_with_preceding_and_following = False
# Does the backend support CAST with precision?
supports_cast_with_precision = True
# How many second decimals does the database return when casting a value to
# a type with time?
time_cast_precision = 6
# SQL to create a procedure for use by the Django test suite. The
# functionality of the procedure isn't important.
create_test_procedure_without_params_sql = None
create_test_procedure_with_int_param_sql = None
# Does the backend support keyword parameters for cursor.callproc()?
supports_callproc_kwargs = False
# What formats does the backend EXPLAIN syntax support?
supported_explain_formats = set()
# Does DatabaseOperations.explain_query_prefix() raise ValueError if
# unknown kwargs are passed to QuerySet.explain()?
validates_explain_options = True
# Does the backend support the default parameter in lead() and lag()?
supports_default_in_lead_lag = True
# Does the backend support ignoring constraint or uniqueness errors during
# INSERT?
supports_ignore_conflicts = True
# Does the backend support updating rows on constraint or uniqueness errors
# during INSERT?
supports_update_conflicts = False
supports_update_conflicts_with_target = False
# Does this backend require casting the results of CASE expressions used
# in UPDATE statements to ensure the expression has the correct type?
requires_casted_case_in_updates = False
# Does the backend support partial indexes (CREATE INDEX ... WHERE ...)?
supports_partial_indexes = True
supports_functions_in_partial_indexes = True
# Does the backend support covering indexes (CREATE INDEX ... INCLUDE ...)?
supports_covering_indexes = False
# Does the backend support indexes on expressions?
supports_expression_indexes = True
# Does the backend treat COLLATE as an indexed expression?
collate_as_index_expression = False
# Does the database allow more than one constraint or index on the same
# field(s)?
allows_multiple_constraints_on_same_fields = True
# Does the backend support boolean expressions in SELECT and GROUP BY
# clauses?
supports_boolean_expr_in_select_clause = True
# Does the backend support JSONField?
supports_json_field = True
# Can the backend introspect a JSONField?
can_introspect_json_field = True
# Does the backend support primitives in JSONField?
supports_primitives_in_json_field = True
# Is there a true datatype for JSON?
has_native_json_field = False
# Does the backend use PostgreSQL-style JSON operators like '->'?
has_json_operators = False
# Does the backend support __contains and __contained_by lookups for
# a JSONField?
supports_json_field_contains = True
# Does value__d__contains={'f': 'g'} (without a list around the dict) match
# {'d': [{'f': 'g'}]}?
json_key_contains_list_matching_requires_list = False
# Does the backend support JSONObject() database function?
has_json_object_function = True
# Does the backend support column collations?
supports_collation_on_charfield = True
supports_collation_on_textfield = True
# Does the backend support non-deterministic collations?
supports_non_deterministic_collations = True
# Collation names for use by the Django test suite.
test_collations = {
'ci': None, # Case-insensitive.
'cs': None, # Case-sensitive.
'non_default': None, # Non-default.
'swedish_ci': None # Swedish case-insensitive.
}
# SQL template override for tests.aggregation.tests.NowUTC
test_now_utc_template = None
# A set of dotted paths to tests in Django's test suite that are expected
# to fail on this database.
django_test_expected_failures = set()
# A map of reasons to sets of dotted paths to tests in Django's test suite
# that should be skipped for this database.
django_test_skips = {}
def __init__(self, connection):
self.connection = connection
@cached_property
def supports_explaining_query_execution(self):
"""Does this backend support explaining query execution?"""
return self.connection.ops.explain_prefix is not None
@cached_property
def supports_transactions(self):
"""Confirm support for transactions."""
with self.connection.cursor() as cursor:
cursor.execute('CREATE TABLE ROLLBACK_TEST (X INT)')
self.connection.set_autocommit(False)
cursor.execute('INSERT INTO ROLLBACK_TEST (X) VALUES (8)')
self.connection.rollback()
self.connection.set_autocommit(True)
cursor.execute('SELECT COUNT(X) FROM ROLLBACK_TEST')
count, = cursor.fetchone()
cursor.execute('DROP TABLE ROLLBACK_TEST')
return count == 0
def allows_group_by_selected_pks_on_model(self, model):
if not self.allows_group_by_selected_pks:
return False
return model._meta.managed
|
4c9614343fa7a86f8c7693c19af1ce4cc6a183aad62f8ab0f3a8413744367f88 | from collections import namedtuple
# Structure returned by DatabaseIntrospection.get_table_list()
TableInfo = namedtuple('TableInfo', ['name', 'type'])
# Structure returned by the DB-API cursor.description interface (PEP 249)
FieldInfo = namedtuple(
'FieldInfo',
'name type_code display_size internal_size precision scale null_ok '
'default collation'
)
class BaseDatabaseIntrospection:
"""Encapsulate backend-specific introspection utilities."""
data_types_reverse = {}
def __init__(self, connection):
self.connection = connection
def get_field_type(self, data_type, description):
"""
Hook for a database backend to use the cursor description to
match a Django field type to a database column.
For Oracle, the column data_type on its own is insufficient to
distinguish between a FloatField and IntegerField, for example.
"""
return self.data_types_reverse[data_type]
def identifier_converter(self, name):
"""
Apply a conversion to the identifier for the purposes of comparison.
The default identifier converter is for case sensitive comparison.
"""
return name
def table_names(self, cursor=None, include_views=False):
"""
Return a list of names of all tables that exist in the database.
Sort the returned table list by Python's default sorting. Do NOT use
the database's ORDER BY here to avoid subtle differences in sorting
order between databases.
"""
def get_names(cursor):
return sorted(ti.name for ti in self.get_table_list(cursor)
if include_views or ti.type == 't')
if cursor is None:
with self.connection.cursor() as cursor:
return get_names(cursor)
return get_names(cursor)
def get_table_list(self, cursor):
"""
Return an unsorted list of TableInfo named tuples of all tables and
views that exist in the database.
"""
raise NotImplementedError('subclasses of BaseDatabaseIntrospection may require a get_table_list() method')
def get_table_description(self, cursor, table_name):
"""
Return a description of the table with the DB-API cursor.description
interface.
"""
raise NotImplementedError(
'subclasses of BaseDatabaseIntrospection may require a '
'get_table_description() method.'
)
def get_migratable_models(self):
from django.apps import apps
from django.db import router
return (
model
for app_config in apps.get_app_configs()
for model in router.get_migratable_models(app_config, self.connection.alias)
if model._meta.can_migrate(self.connection)
)
def django_table_names(self, only_existing=False, include_views=True):
"""
Return a list of all table names that have associated Django models and
are in INSTALLED_APPS.
If only_existing is True, include only the tables in the database.
"""
tables = set()
for model in self.get_migratable_models():
if not model._meta.managed:
continue
tables.add(model._meta.db_table)
tables.update(
f.m2m_db_table() for f in model._meta.local_many_to_many
if f.remote_field.through._meta.managed
)
tables = list(tables)
if only_existing:
existing_tables = set(self.table_names(include_views=include_views))
tables = [
t
for t in tables
if self.identifier_converter(t) in existing_tables
]
return tables
def installed_models(self, tables):
"""
Return a set of all models represented by the provided list of table
names.
"""
tables = set(map(self.identifier_converter, tables))
return {
m for m in self.get_migratable_models()
if self.identifier_converter(m._meta.db_table) in tables
}
def sequence_list(self):
"""
Return a list of information about all DB sequences for all models in
all apps.
"""
sequence_list = []
with self.connection.cursor() as cursor:
for model in self.get_migratable_models():
if not model._meta.managed:
continue
if model._meta.swapped:
continue
sequence_list.extend(self.get_sequences(cursor, model._meta.db_table, model._meta.local_fields))
for f in model._meta.local_many_to_many:
# If this is an m2m using an intermediate table,
# we don't need to reset the sequence.
if f.remote_field.through._meta.auto_created:
sequence = self.get_sequences(cursor, f.m2m_db_table())
sequence_list.extend(sequence or [{'table': f.m2m_db_table(), 'column': None}])
return sequence_list
def get_sequences(self, cursor, table_name, table_fields=()):
"""
Return a list of introspected sequences for table_name. Each sequence
is a dict: {'table': <table_name>, 'column': <column_name>}. An optional
'name' key can be added if the backend supports named sequences.
"""
raise NotImplementedError('subclasses of BaseDatabaseIntrospection may require a get_sequences() method')
def get_relations(self, cursor, table_name):
"""
Return a dictionary of {field_name: (field_name_other_table, other_table)}
representing all foreign keys in the given table.
"""
raise NotImplementedError(
'subclasses of BaseDatabaseIntrospection may require a '
'get_relations() method.'
)
def get_primary_key_column(self, cursor, table_name):
"""
Return the name of the primary key column for the given table.
"""
for constraint in self.get_constraints(cursor, table_name).values():
if constraint['primary_key']:
return constraint['columns'][0]
return None
def get_constraints(self, cursor, table_name):
"""
Retrieve any constraints or keys (unique, pk, fk, check, index)
across one or more columns.
Return a dict mapping constraint names to their attributes,
where attributes is a dict with keys:
* columns: List of columns this covers
* primary_key: True if primary key, False otherwise
* unique: True if this is a unique constraint, False otherwise
* foreign_key: (table, column) of target, or None
* check: True if check constraint, False otherwise
* index: True if index, False otherwise.
* orders: The order (ASC/DESC) defined for the columns of indexes
* type: The type of the index (btree, hash, etc.)
Some backends may return special constraint names that don't exist
if they don't name constraints of a certain type (e.g. SQLite)
"""
raise NotImplementedError('subclasses of BaseDatabaseIntrospection may require a get_constraints() method')
|
09063a72cf877d53d586019412fc7e17bdcd95e4197b65cf108273037fe344d2 | import _thread
import copy
import threading
import time
import warnings
from collections import deque
from contextlib import contextmanager
try:
import zoneinfo
except ImportError:
from backports import zoneinfo
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import DEFAULT_DB_ALIAS, DatabaseError
from django.db.backends import utils
from django.db.backends.base.validation import BaseDatabaseValidation
from django.db.backends.signals import connection_created
from django.db.transaction import TransactionManagementError
from django.db.utils import DatabaseErrorWrapper
from django.utils import timezone
from django.utils.asyncio import async_unsafe
from django.utils.functional import cached_property
NO_DB_ALIAS = '__no_db__'
# RemovedInDjango50Warning
def timezone_constructor(tzname):
if settings.USE_DEPRECATED_PYTZ:
import pytz
return pytz.timezone(tzname)
return zoneinfo.ZoneInfo(tzname)
class BaseDatabaseWrapper:
"""Represent a database connection."""
# Mapping of Field objects to their column types.
data_types = {}
# Mapping of Field objects to their SQL suffix such as AUTOINCREMENT.
data_types_suffix = {}
# Mapping of Field objects to their SQL for CHECK constraints.
data_type_check_constraints = {}
ops = None
vendor = 'unknown'
display_name = 'unknown'
SchemaEditorClass = None
# Classes instantiated in __init__().
client_class = None
creation_class = None
features_class = None
introspection_class = None
ops_class = None
validation_class = BaseDatabaseValidation
queries_limit = 9000
def __init__(self, settings_dict, alias=DEFAULT_DB_ALIAS):
# Connection related attributes.
# The underlying database connection.
self.connection = None
# `settings_dict` should be a dictionary containing keys such as
# NAME, USER, etc. It's called `settings_dict` instead of `settings`
# to disambiguate it from Django settings modules.
self.settings_dict = settings_dict
self.alias = alias
# Query logging in debug mode or when explicitly enabled.
self.queries_log = deque(maxlen=self.queries_limit)
self.force_debug_cursor = False
# Transaction related attributes.
# Tracks if the connection is in autocommit mode. Per PEP 249, by
# default, it isn't.
self.autocommit = False
# Tracks if the connection is in a transaction managed by 'atomic'.
self.in_atomic_block = False
# Increment to generate unique savepoint ids.
self.savepoint_state = 0
# List of savepoints created by 'atomic'.
self.savepoint_ids = []
# Stack of active 'atomic' blocks.
self.atomic_blocks = []
# Tracks if the outermost 'atomic' block should commit on exit,
# ie. if autocommit was active on entry.
self.commit_on_exit = True
# Tracks if the transaction should be rolled back to the next
# available savepoint because of an exception in an inner block.
self.needs_rollback = False
# Connection termination related attributes.
self.close_at = None
self.closed_in_transaction = False
self.errors_occurred = False
self.health_check_enabled = False
self.health_check_done = False
# Thread-safety related attributes.
self._thread_sharing_lock = threading.Lock()
self._thread_sharing_count = 0
self._thread_ident = _thread.get_ident()
# A list of no-argument functions to run when the transaction commits.
# Each entry is an (sids, func) tuple, where sids is a set of the
# active savepoint IDs when this function was registered.
self.run_on_commit = []
# Should we run the on-commit hooks the next time set_autocommit(True)
# is called?
self.run_commit_hooks_on_set_autocommit_on = False
# A stack of wrappers to be invoked around execute()/executemany()
# calls. Each entry is a function taking five arguments: execute, sql,
# params, many, and context. It's the function's responsibility to
# call execute(sql, params, many, context).
self.execute_wrappers = []
self.client = self.client_class(self)
self.creation = self.creation_class(self)
self.features = self.features_class(self)
self.introspection = self.introspection_class(self)
self.ops = self.ops_class(self)
self.validation = self.validation_class(self)
def __repr__(self):
return (
f'<{self.__class__.__qualname__} '
f'vendor={self.vendor!r} alias={self.alias!r}>'
)
def ensure_timezone(self):
"""
Ensure the connection's timezone is set to `self.timezone_name` and
return whether it changed or not.
"""
return False
@cached_property
def timezone(self):
"""
Return a tzinfo of the database connection time zone.
This is only used when time zone support is enabled. When a datetime is
read from the database, it is always returned in this time zone.
When the database backend supports time zones, it doesn't matter which
time zone Django uses, as long as aware datetimes are used everywhere.
Other users connecting to the database can choose their own time zone.
When the database backend doesn't support time zones, the time zone
Django uses may be constrained by the requirements of other users of
the database.
"""
if not settings.USE_TZ:
return None
elif self.settings_dict['TIME_ZONE'] is None:
return timezone.utc
else:
return timezone_constructor(self.settings_dict['TIME_ZONE'])
@cached_property
def timezone_name(self):
"""
Name of the time zone of the database connection.
"""
if not settings.USE_TZ:
return settings.TIME_ZONE
elif self.settings_dict['TIME_ZONE'] is None:
return 'UTC'
else:
return self.settings_dict['TIME_ZONE']
@property
def queries_logged(self):
return self.force_debug_cursor or settings.DEBUG
@property
def queries(self):
if len(self.queries_log) == self.queries_log.maxlen:
warnings.warn(
"Limit for query logging exceeded, only the last {} queries "
"will be returned.".format(self.queries_log.maxlen))
return list(self.queries_log)
# ##### Backend-specific methods for creating connections and cursors #####
def get_connection_params(self):
"""Return a dict of parameters suitable for get_new_connection."""
raise NotImplementedError('subclasses of BaseDatabaseWrapper may require a get_connection_params() method')
def get_new_connection(self, conn_params):
"""Open a connection to the database."""
raise NotImplementedError('subclasses of BaseDatabaseWrapper may require a get_new_connection() method')
def init_connection_state(self):
"""Initialize the database connection settings."""
raise NotImplementedError('subclasses of BaseDatabaseWrapper may require an init_connection_state() method')
def create_cursor(self, name=None):
"""Create a cursor. Assume that a connection is established."""
raise NotImplementedError('subclasses of BaseDatabaseWrapper may require a create_cursor() method')
# ##### Backend-specific methods for creating connections #####
@async_unsafe
def connect(self):
"""Connect to the database. Assume that the connection is closed."""
# Check for invalid configurations.
self.check_settings()
# In case the previous connection was closed while in an atomic block
self.in_atomic_block = False
self.savepoint_ids = []
self.atomic_blocks = []
self.needs_rollback = False
# Reset parameters defining when to close/health-check the connection.
self.health_check_enabled = self.settings_dict['CONN_HEALTH_CHECKS']
max_age = self.settings_dict['CONN_MAX_AGE']
self.close_at = None if max_age is None else time.monotonic() + max_age
self.closed_in_transaction = False
self.errors_occurred = False
# New connections are healthy.
self.health_check_done = True
# Establish the connection
conn_params = self.get_connection_params()
self.connection = self.get_new_connection(conn_params)
self.set_autocommit(self.settings_dict['AUTOCOMMIT'])
self.init_connection_state()
connection_created.send(sender=self.__class__, connection=self)
self.run_on_commit = []
def check_settings(self):
if self.settings_dict['TIME_ZONE'] is not None and not settings.USE_TZ:
raise ImproperlyConfigured(
"Connection '%s' cannot set TIME_ZONE because USE_TZ is False."
% self.alias
)
@async_unsafe
def ensure_connection(self):
"""Guarantee that a connection to the database is established."""
if self.connection is None:
with self.wrap_database_errors:
self.connect()
# ##### Backend-specific wrappers for PEP-249 connection methods #####
def _prepare_cursor(self, cursor):
"""
Validate the connection is usable and perform database cursor wrapping.
"""
self.validate_thread_sharing()
if self.queries_logged:
wrapped_cursor = self.make_debug_cursor(cursor)
else:
wrapped_cursor = self.make_cursor(cursor)
return wrapped_cursor
def _cursor(self, name=None):
self.close_if_health_check_failed()
self.ensure_connection()
with self.wrap_database_errors:
return self._prepare_cursor(self.create_cursor(name))
def _commit(self):
if self.connection is not None:
with self.wrap_database_errors:
return self.connection.commit()
def _rollback(self):
if self.connection is not None:
with self.wrap_database_errors:
return self.connection.rollback()
def _close(self):
if self.connection is not None:
with self.wrap_database_errors:
return self.connection.close()
# ##### Generic wrappers for PEP-249 connection methods #####
@async_unsafe
def cursor(self):
"""Create a cursor, opening a connection if necessary."""
return self._cursor()
@async_unsafe
def commit(self):
"""Commit a transaction and reset the dirty flag."""
self.validate_thread_sharing()
self.validate_no_atomic_block()
self._commit()
# A successful commit means that the database connection works.
self.errors_occurred = False
self.run_commit_hooks_on_set_autocommit_on = True
@async_unsafe
def rollback(self):
"""Roll back a transaction and reset the dirty flag."""
self.validate_thread_sharing()
self.validate_no_atomic_block()
self._rollback()
# A successful rollback means that the database connection works.
self.errors_occurred = False
self.needs_rollback = False
self.run_on_commit = []
@async_unsafe
def close(self):
"""Close the connection to the database."""
self.validate_thread_sharing()
self.run_on_commit = []
# Don't call validate_no_atomic_block() to avoid making it difficult
# to get rid of a connection in an invalid state. The next connect()
# will reset the transaction state anyway.
if self.closed_in_transaction or self.connection is None:
return
try:
self._close()
finally:
if self.in_atomic_block:
self.closed_in_transaction = True
self.needs_rollback = True
else:
self.connection = None
# ##### Backend-specific savepoint management methods #####
def _savepoint(self, sid):
with self.cursor() as cursor:
cursor.execute(self.ops.savepoint_create_sql(sid))
def _savepoint_rollback(self, sid):
with self.cursor() as cursor:
cursor.execute(self.ops.savepoint_rollback_sql(sid))
def _savepoint_commit(self, sid):
with self.cursor() as cursor:
cursor.execute(self.ops.savepoint_commit_sql(sid))
def _savepoint_allowed(self):
# Savepoints cannot be created outside a transaction
return self.features.uses_savepoints and not self.get_autocommit()
# ##### Generic savepoint management methods #####
@async_unsafe
def savepoint(self):
"""
Create a savepoint inside the current transaction. Return an
identifier for the savepoint that will be used for the subsequent
rollback or commit. Do nothing if savepoints are not supported.
"""
if not self._savepoint_allowed():
return
thread_ident = _thread.get_ident()
tid = str(thread_ident).replace('-', '')
self.savepoint_state += 1
sid = "s%s_x%d" % (tid, self.savepoint_state)
self.validate_thread_sharing()
self._savepoint(sid)
return sid
@async_unsafe
def savepoint_rollback(self, sid):
"""
Roll back to a savepoint. Do nothing if savepoints are not supported.
"""
if not self._savepoint_allowed():
return
self.validate_thread_sharing()
self._savepoint_rollback(sid)
# Remove any callbacks registered while this savepoint was active.
self.run_on_commit = [
(sids, func) for (sids, func) in self.run_on_commit if sid not in sids
]
@async_unsafe
def savepoint_commit(self, sid):
"""
Release a savepoint. Do nothing if savepoints are not supported.
"""
if not self._savepoint_allowed():
return
self.validate_thread_sharing()
self._savepoint_commit(sid)
@async_unsafe
def clean_savepoints(self):
"""
Reset the counter used to generate unique savepoint ids in this thread.
"""
self.savepoint_state = 0
# ##### Backend-specific transaction management methods #####
def _set_autocommit(self, autocommit):
"""
Backend-specific implementation to enable or disable autocommit.
"""
raise NotImplementedError('subclasses of BaseDatabaseWrapper may require a _set_autocommit() method')
# ##### Generic transaction management methods #####
def get_autocommit(self):
"""Get the autocommit state."""
self.ensure_connection()
return self.autocommit
def set_autocommit(self, autocommit, force_begin_transaction_with_broken_autocommit=False):
"""
Enable or disable autocommit.
The usual way to start a transaction is to turn autocommit off.
SQLite does not properly start a transaction when disabling
autocommit. To avoid this buggy behavior and to actually enter a new
transaction, an explicit BEGIN is required. Using
force_begin_transaction_with_broken_autocommit=True will issue an
explicit BEGIN with SQLite. This option will be ignored for other
backends.
"""
self.validate_no_atomic_block()
self.close_if_health_check_failed()
self.ensure_connection()
start_transaction_under_autocommit = (
force_begin_transaction_with_broken_autocommit and not autocommit and
hasattr(self, '_start_transaction_under_autocommit')
)
if start_transaction_under_autocommit:
self._start_transaction_under_autocommit()
else:
self._set_autocommit(autocommit)
self.autocommit = autocommit
if autocommit and self.run_commit_hooks_on_set_autocommit_on:
self.run_and_clear_commit_hooks()
self.run_commit_hooks_on_set_autocommit_on = False
def get_rollback(self):
"""Get the "needs rollback" flag -- for *advanced use* only."""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
return self.needs_rollback
def set_rollback(self, rollback):
"""
Set or unset the "needs rollback" flag -- for *advanced use* only.
"""
if not self.in_atomic_block:
raise TransactionManagementError(
"The rollback flag doesn't work outside of an 'atomic' block.")
self.needs_rollback = rollback
def validate_no_atomic_block(self):
"""Raise an error if an atomic block is active."""
if self.in_atomic_block:
raise TransactionManagementError(
"This is forbidden when an 'atomic' block is active.")
def validate_no_broken_transaction(self):
if self.needs_rollback:
raise TransactionManagementError(
"An error occurred in the current transaction. You can't "
"execute queries until the end of the 'atomic' block.")
# ##### Foreign key constraints checks handling #####
@contextmanager
def constraint_checks_disabled(self):
"""
Disable foreign key constraint checking.
"""
disabled = self.disable_constraint_checking()
try:
yield
finally:
if disabled:
self.enable_constraint_checking()
def disable_constraint_checking(self):
"""
Backends can implement as needed to temporarily disable foreign key
constraint checking. Should return True if the constraints were
disabled and will need to be reenabled.
"""
return False
def enable_constraint_checking(self):
"""
Backends can implement as needed to re-enable foreign key constraint
checking.
"""
pass
def check_constraints(self, table_names=None):
"""
Backends can override this method if they can apply constraint
checking (e.g. via "SET CONSTRAINTS ALL IMMEDIATE"). Should raise an
IntegrityError if any invalid foreign key references are encountered.
"""
pass
# ##### Connection termination handling #####
def is_usable(self):
"""
Test if the database connection is usable.
This method may assume that self.connection is not None.
Actual implementations should take care not to raise exceptions
as that may prevent Django from recycling unusable connections.
"""
raise NotImplementedError(
"subclasses of BaseDatabaseWrapper may require an is_usable() method")
def close_if_health_check_failed(self):
"""Close existing connection if it fails a health check."""
if (
self.connection is None or
not self.health_check_enabled or
self.health_check_done
):
return
if not self.is_usable():
self.close()
self.health_check_done = True
def close_if_unusable_or_obsolete(self):
"""
Close the current connection if unrecoverable errors have occurred
or if it outlived its maximum age.
"""
if self.connection is not None:
self.health_check_done = False
# If the application didn't restore the original autocommit setting,
# don't take chances, drop the connection.
if self.get_autocommit() != self.settings_dict['AUTOCOMMIT']:
self.close()
return
# If an exception other than DataError or IntegrityError occurred
# since the last commit / rollback, check if the connection works.
if self.errors_occurred:
if self.is_usable():
self.errors_occurred = False
self.health_check_done = True
else:
self.close()
return
if self.close_at is not None and time.monotonic() >= self.close_at:
self.close()
return
# ##### Thread safety handling #####
@property
def allow_thread_sharing(self):
with self._thread_sharing_lock:
return self._thread_sharing_count > 0
def inc_thread_sharing(self):
with self._thread_sharing_lock:
self._thread_sharing_count += 1
def dec_thread_sharing(self):
with self._thread_sharing_lock:
if self._thread_sharing_count <= 0:
raise RuntimeError('Cannot decrement the thread sharing count below zero.')
self._thread_sharing_count -= 1
def validate_thread_sharing(self):
"""
Validate that the connection isn't accessed by another thread than the
one which originally created it, unless the connection was explicitly
authorized to be shared between threads (via the `inc_thread_sharing()`
method). Raise an exception if the validation fails.
"""
if not (self.allow_thread_sharing or self._thread_ident == _thread.get_ident()):
raise DatabaseError(
"DatabaseWrapper objects created in a "
"thread can only be used in that same thread. The object "
"with alias '%s' was created in thread id %s and this is "
"thread id %s."
% (self.alias, self._thread_ident, _thread.get_ident())
)
# ##### Miscellaneous #####
def prepare_database(self):
"""
Hook to do any database check or preparation, generally called before
migrating a project or an app.
"""
pass
@cached_property
def wrap_database_errors(self):
"""
Context manager and decorator that re-throws backend-specific database
exceptions using Django's common wrappers.
"""
return DatabaseErrorWrapper(self)
def chunked_cursor(self):
"""
Return a cursor that tries to avoid caching in the database (if
supported by the database), otherwise return a regular cursor.
"""
return self.cursor()
def make_debug_cursor(self, cursor):
"""Create a cursor that logs all queries in self.queries_log."""
return utils.CursorDebugWrapper(cursor, self)
def make_cursor(self, cursor):
"""Create a cursor without debug logging."""
return utils.CursorWrapper(cursor, self)
@contextmanager
def temporary_connection(self):
"""
Context manager that ensures that a connection is established, and
if it opened one, closes it to avoid leaving a dangling connection.
This is useful for operations outside of the request-response cycle.
Provide a cursor: with self.temporary_connection() as cursor: ...
"""
must_close = self.connection is None
try:
with self.cursor() as cursor:
yield cursor
finally:
if must_close:
self.close()
@contextmanager
def _nodb_cursor(self):
"""
Return a cursor from an alternative connection to be used when there is
no need to access the main database, specifically for test db
creation/deletion. This also prevents the production database from
being exposed to potential child threads while (or after) the test
database is destroyed. Refs #10868, #17786, #16969.
"""
conn = self.__class__({**self.settings_dict, 'NAME': None}, alias=NO_DB_ALIAS)
try:
with conn.cursor() as cursor:
yield cursor
finally:
conn.close()
def schema_editor(self, *args, **kwargs):
"""
Return a new instance of this backend's SchemaEditor.
"""
if self.SchemaEditorClass is None:
raise NotImplementedError(
'The SchemaEditorClass attribute of this database wrapper is still None')
return self.SchemaEditorClass(self, *args, **kwargs)
def on_commit(self, func):
if not callable(func):
raise TypeError("on_commit()'s callback must be a callable.")
if self.in_atomic_block:
# Transaction in progress; save for execution on commit.
self.run_on_commit.append((set(self.savepoint_ids), func))
elif not self.get_autocommit():
raise TransactionManagementError('on_commit() cannot be used in manual transaction management')
else:
# No transaction in progress and in autocommit mode; execute
# immediately.
func()
def run_and_clear_commit_hooks(self):
self.validate_no_atomic_block()
current_run_on_commit = self.run_on_commit
self.run_on_commit = []
while current_run_on_commit:
sids, func = current_run_on_commit.pop(0)
func()
@contextmanager
def execute_wrapper(self, wrapper):
"""
Return a context manager under which the wrapper is applied to suitable
database query executions.
"""
self.execute_wrappers.append(wrapper)
try:
yield
finally:
self.execute_wrappers.pop()
def copy(self, alias=None):
"""
Return a copy of this connection.
For tests that require two connections to the same database.
"""
settings_dict = copy.deepcopy(self.settings_dict)
if alias is None:
alias = self.alias
return type(self)(settings_dict, alias)
|
0e969aae4a7d5bb9277d44364c77103558bd89479af49740af572ac72181ecd0 | import datetime
import decimal
from importlib import import_module
import sqlparse
from django.conf import settings
from django.db import NotSupportedError, transaction
from django.db.backends import utils
from django.utils import timezone
from django.utils.encoding import force_str
class BaseDatabaseOperations:
"""
Encapsulate backend-specific differences, such as the way a backend
performs ordering or calculates the ID of a recently-inserted row.
"""
compiler_module = "django.db.models.sql.compiler"
# Integer field safe ranges by `internal_type` as documented
# in docs/ref/models/fields.txt.
integer_field_ranges = {
'SmallIntegerField': (-32768, 32767),
'IntegerField': (-2147483648, 2147483647),
'BigIntegerField': (-9223372036854775808, 9223372036854775807),
'PositiveBigIntegerField': (0, 9223372036854775807),
'PositiveSmallIntegerField': (0, 32767),
'PositiveIntegerField': (0, 2147483647),
'SmallAutoField': (-32768, 32767),
'AutoField': (-2147483648, 2147483647),
'BigAutoField': (-9223372036854775808, 9223372036854775807),
}
set_operators = {
'union': 'UNION',
'intersection': 'INTERSECT',
'difference': 'EXCEPT',
}
# Mapping of Field.get_internal_type() (typically the model field's class
# name) to the data type to use for the Cast() function, if different from
# DatabaseWrapper.data_types.
cast_data_types = {}
# CharField data type if the max_length argument isn't provided.
cast_char_field_without_max_length = None
# Start and end points for window expressions.
PRECEDING = 'PRECEDING'
FOLLOWING = 'FOLLOWING'
UNBOUNDED_PRECEDING = 'UNBOUNDED ' + PRECEDING
UNBOUNDED_FOLLOWING = 'UNBOUNDED ' + FOLLOWING
CURRENT_ROW = 'CURRENT ROW'
# Prefix for EXPLAIN queries, or None EXPLAIN isn't supported.
explain_prefix = None
def __init__(self, connection):
self.connection = connection
self._cache = None
def autoinc_sql(self, table, column):
"""
Return any SQL needed to support auto-incrementing primary keys, or
None if no SQL is necessary.
This SQL is executed when a table is created.
"""
return None
def bulk_batch_size(self, fields, objs):
"""
Return the maximum allowed batch size for the backend. The fields
are the fields going to be inserted in the batch, the objs contains
all the objects to be inserted.
"""
return len(objs)
def format_for_duration_arithmetic(self, sql):
raise NotImplementedError(
'subclasses of BaseDatabaseOperations may require a '
'format_for_duration_arithmetic() method.'
)
def cache_key_culling_sql(self):
"""
Return an SQL query that retrieves the first cache key greater than the
n smallest.
This is used by the 'db' cache backend to determine where to start
culling.
"""
cache_key = self.quote_name('cache_key')
return f'SELECT {cache_key} FROM %s ORDER BY {cache_key} LIMIT 1 OFFSET %%s'
def unification_cast_sql(self, output_field):
"""
Given a field instance, return the SQL that casts the result of a union
to that type. The resulting string should contain a '%s' placeholder
for the expression being cast.
"""
return '%s'
def date_extract_sql(self, lookup_type, field_name):
"""
Given a lookup_type of 'year', 'month', or 'day', return the SQL that
extracts a value from the given date field field_name.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a date_extract_sql() method')
def date_trunc_sql(self, lookup_type, field_name, tzname=None):
"""
Given a lookup_type of 'year', 'month', or 'day', return the SQL that
truncates the given date or datetime field field_name to a date object
with only the given specificity.
If `tzname` is provided, the given value is truncated in a specific
timezone.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a date_trunc_sql() method.')
def datetime_cast_date_sql(self, field_name, tzname):
"""
Return the SQL to cast a datetime value to date value.
"""
raise NotImplementedError(
'subclasses of BaseDatabaseOperations may require a '
'datetime_cast_date_sql() method.'
)
def datetime_cast_time_sql(self, field_name, tzname):
"""
Return the SQL to cast a datetime value to time value.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a datetime_cast_time_sql() method')
def datetime_extract_sql(self, lookup_type, field_name, tzname):
"""
Given a lookup_type of 'year', 'month', 'day', 'hour', 'minute', or
'second', return the SQL that extracts a value from the given
datetime field field_name.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a datetime_extract_sql() method')
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
"""
Given a lookup_type of 'year', 'month', 'day', 'hour', 'minute', or
'second', return the SQL that truncates the given datetime field
field_name to a datetime object with only the given specificity.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a datetime_trunc_sql() method')
def time_trunc_sql(self, lookup_type, field_name, tzname=None):
"""
Given a lookup_type of 'hour', 'minute' or 'second', return the SQL
that truncates the given time or datetime field field_name to a time
object with only the given specificity.
If `tzname` is provided, the given value is truncated in a specific
timezone.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a time_trunc_sql() method')
def time_extract_sql(self, lookup_type, field_name):
"""
Given a lookup_type of 'hour', 'minute', or 'second', return the SQL
that extracts a value from the given time field field_name.
"""
return self.date_extract_sql(lookup_type, field_name)
def deferrable_sql(self):
"""
Return the SQL to make a constraint "initially deferred" during a
CREATE TABLE statement.
"""
return ''
def distinct_sql(self, fields, params):
"""
Return an SQL DISTINCT clause which removes duplicate rows from the
result set. If any fields are given, only check the given fields for
duplicates.
"""
if fields:
raise NotSupportedError('DISTINCT ON fields is not supported by this database backend')
else:
return ['DISTINCT'], []
def fetch_returned_insert_columns(self, cursor, returning_params):
"""
Given a cursor object that has just performed an INSERT...RETURNING
statement into a table, return the newly created data.
"""
return cursor.fetchone()
def field_cast_sql(self, db_type, internal_type):
"""
Given a column type (e.g. 'BLOB', 'VARCHAR') and an internal type
(e.g. 'GenericIPAddressField'), return the SQL to cast it before using
it in a WHERE statement. The resulting string should contain a '%s'
placeholder for the column being searched against.
"""
return '%s'
def force_no_ordering(self):
"""
Return a list used in the "ORDER BY" clause to force no ordering at
all. Return an empty list to include nothing in the ordering.
"""
return []
def for_update_sql(self, nowait=False, skip_locked=False, of=(), no_key=False):
"""
Return the FOR UPDATE SQL clause to lock rows for an update operation.
"""
return 'FOR%s UPDATE%s%s%s' % (
' NO KEY' if no_key else '',
' OF %s' % ', '.join(of) if of else '',
' NOWAIT' if nowait else '',
' SKIP LOCKED' if skip_locked else '',
)
def _get_limit_offset_params(self, low_mark, high_mark):
offset = low_mark or 0
if high_mark is not None:
return (high_mark - offset), offset
elif offset:
return self.connection.ops.no_limit_value(), offset
return None, offset
def limit_offset_sql(self, low_mark, high_mark):
"""Return LIMIT/OFFSET SQL clause."""
limit, offset = self._get_limit_offset_params(low_mark, high_mark)
return ' '.join(sql for sql in (
('LIMIT %d' % limit) if limit else None,
('OFFSET %d' % offset) if offset else None,
) if sql)
def last_executed_query(self, cursor, sql, params):
"""
Return a string of the query last executed by the given cursor, with
placeholders replaced with actual values.
`sql` is the raw query containing placeholders and `params` is the
sequence of parameters. These are used by default, but this method
exists for database backends to provide a better implementation
according to their own quoting schemes.
"""
# Convert params to contain string values.
def to_string(s):
return force_str(s, strings_only=True, errors='replace')
if isinstance(params, (list, tuple)):
u_params = tuple(to_string(val) for val in params)
elif params is None:
u_params = ()
else:
u_params = {to_string(k): to_string(v) for k, v in params.items()}
return "QUERY = %r - PARAMS = %r" % (sql, u_params)
def last_insert_id(self, cursor, table_name, pk_name):
"""
Given a cursor object that has just performed an INSERT statement into
a table that has an auto-incrementing ID, return the newly created ID.
`pk_name` is the name of the primary-key column.
"""
return cursor.lastrowid
def lookup_cast(self, lookup_type, internal_type=None):
"""
Return the string to use in a query when performing lookups
("contains", "like", etc.). It should contain a '%s' placeholder for
the column being searched against.
"""
return "%s"
def max_in_list_size(self):
"""
Return the maximum number of items that can be passed in a single 'IN'
list condition, or None if the backend does not impose a limit.
"""
return None
def max_name_length(self):
"""
Return the maximum length of table and column names, or None if there
is no limit.
"""
return None
def no_limit_value(self):
"""
Return the value to use for the LIMIT when we are wanting "LIMIT
infinity". Return None if the limit clause can be omitted in this case.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a no_limit_value() method')
def pk_default_value(self):
"""
Return the value to use during an INSERT statement to specify that
the field should use its default value.
"""
return 'DEFAULT'
def prepare_sql_script(self, sql):
"""
Take an SQL script that may contain multiple lines and return a list
of statements to feed to successive cursor.execute() calls.
Since few databases are able to process raw SQL scripts in a single
cursor.execute() call and PEP 249 doesn't talk about this use case,
the default implementation is conservative.
"""
return [
sqlparse.format(statement, strip_comments=True)
for statement in sqlparse.split(sql) if statement
]
def process_clob(self, value):
"""
Return the value of a CLOB column, for backends that return a locator
object that requires additional processing.
"""
return value
def return_insert_columns(self, fields):
"""
For backends that support returning columns as part of an insert query,
return the SQL and params to append to the INSERT query. The returned
fragment should contain a format string to hold the appropriate column.
"""
pass
def compiler(self, compiler_name):
"""
Return the SQLCompiler class corresponding to the given name,
in the namespace corresponding to the `compiler_module` attribute
on this backend.
"""
if self._cache is None:
self._cache = import_module(self.compiler_module)
return getattr(self._cache, compiler_name)
def quote_name(self, name):
"""
Return a quoted version of the given table, index, or column name. Do
not quote the given name if it's already been quoted.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a quote_name() method')
def regex_lookup(self, lookup_type):
"""
Return the string to use in a query when performing regular expression
lookups (using "regex" or "iregex"). It should contain a '%s'
placeholder for the column being searched against.
If the feature is not supported (or part of it is not supported), raise
NotImplementedError.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a regex_lookup() method')
def savepoint_create_sql(self, sid):
"""
Return the SQL for starting a new savepoint. Only required if the
"uses_savepoints" feature is True. The "sid" parameter is a string
for the savepoint id.
"""
return "SAVEPOINT %s" % self.quote_name(sid)
def savepoint_commit_sql(self, sid):
"""
Return the SQL for committing the given savepoint.
"""
return "RELEASE SAVEPOINT %s" % self.quote_name(sid)
def savepoint_rollback_sql(self, sid):
"""
Return the SQL for rolling back the given savepoint.
"""
return "ROLLBACK TO SAVEPOINT %s" % self.quote_name(sid)
def set_time_zone_sql(self):
"""
Return the SQL that will set the connection's time zone.
Return '' if the backend doesn't support time zones.
"""
return ''
def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):
"""
Return a list of SQL statements required to remove all data from
the given database tables (without actually removing the tables
themselves).
The `style` argument is a Style object as returned by either
color_style() or no_style() in django.core.management.color.
If `reset_sequences` is True, the list includes SQL statements required
to reset the sequences.
The `allow_cascade` argument determines whether truncation may cascade
to tables with foreign keys pointing the tables being truncated.
PostgreSQL requires a cascade even if these tables are empty.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations must provide an sql_flush() method')
def execute_sql_flush(self, sql_list):
"""Execute a list of SQL statements to flush the database."""
with transaction.atomic(
using=self.connection.alias,
savepoint=self.connection.features.can_rollback_ddl,
):
with self.connection.cursor() as cursor:
for sql in sql_list:
cursor.execute(sql)
def sequence_reset_by_name_sql(self, style, sequences):
"""
Return a list of the SQL statements required to reset sequences
passed in `sequences`.
The `style` argument is a Style object as returned by either
color_style() or no_style() in django.core.management.color.
"""
return []
def sequence_reset_sql(self, style, model_list):
"""
Return a list of the SQL statements required to reset sequences for
the given models.
The `style` argument is a Style object as returned by either
color_style() or no_style() in django.core.management.color.
"""
return [] # No sequence reset required by default.
def start_transaction_sql(self):
"""Return the SQL statement required to start a transaction."""
return "BEGIN;"
def end_transaction_sql(self, success=True):
"""Return the SQL statement required to end a transaction."""
if not success:
return "ROLLBACK;"
return "COMMIT;"
def tablespace_sql(self, tablespace, inline=False):
"""
Return the SQL that will be used in a query to define the tablespace.
Return '' if the backend doesn't support tablespaces.
If `inline` is True, append the SQL to a row; otherwise append it to
the entire CREATE TABLE or CREATE INDEX statement.
"""
return ''
def prep_for_like_query(self, x):
"""Prepare a value for use in a LIKE query."""
return str(x).replace("\\", "\\\\").replace("%", r"\%").replace("_", r"\_")
# Same as prep_for_like_query(), but called for "iexact" matches, which
# need not necessarily be implemented using "LIKE" in the backend.
prep_for_iexact_query = prep_for_like_query
def validate_autopk_value(self, value):
"""
Certain backends do not accept some values for "serial" fields
(for example zero in MySQL). Raise a ValueError if the value is
invalid, otherwise return the validated value.
"""
return value
def adapt_unknown_value(self, value):
"""
Transform a value to something compatible with the backend driver.
This method only depends on the type of the value. It's designed for
cases where the target type isn't known, such as .raw() SQL queries.
As a consequence it may not work perfectly in all circumstances.
"""
if isinstance(value, datetime.datetime): # must be before date
return self.adapt_datetimefield_value(value)
elif isinstance(value, datetime.date):
return self.adapt_datefield_value(value)
elif isinstance(value, datetime.time):
return self.adapt_timefield_value(value)
elif isinstance(value, decimal.Decimal):
return self.adapt_decimalfield_value(value)
else:
return value
def adapt_datefield_value(self, value):
"""
Transform a date value to an object compatible with what is expected
by the backend driver for date columns.
"""
if value is None:
return None
return str(value)
def adapt_datetimefield_value(self, value):
"""
Transform a datetime value to an object compatible with what is expected
by the backend driver for datetime columns.
"""
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
return str(value)
def adapt_timefield_value(self, value):
"""
Transform a time value to an object compatible with what is expected
by the backend driver for time columns.
"""
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
if timezone.is_aware(value):
raise ValueError("Django does not support timezone-aware times.")
return str(value)
def adapt_decimalfield_value(self, value, max_digits=None, decimal_places=None):
"""
Transform a decimal.Decimal value to an object compatible with what is
expected by the backend driver for decimal (numeric) columns.
"""
return utils.format_number(value, max_digits, decimal_places)
def adapt_ipaddressfield_value(self, value):
"""
Transform a string representation of an IP address into the expected
type for the backend driver.
"""
return value or None
def year_lookup_bounds_for_date_field(self, value, iso_year=False):
"""
Return a two-elements list with the lower and upper bound to be used
with a BETWEEN operator to query a DateField value using a year
lookup.
`value` is an int, containing the looked-up year.
If `iso_year` is True, return bounds for ISO-8601 week-numbering years.
"""
if iso_year:
first = datetime.date.fromisocalendar(value, 1, 1)
second = (
datetime.date.fromisocalendar(value + 1, 1, 1) -
datetime.timedelta(days=1)
)
else:
first = datetime.date(value, 1, 1)
second = datetime.date(value, 12, 31)
first = self.adapt_datefield_value(first)
second = self.adapt_datefield_value(second)
return [first, second]
def year_lookup_bounds_for_datetime_field(self, value, iso_year=False):
"""
Return a two-elements list with the lower and upper bound to be used
with a BETWEEN operator to query a DateTimeField value using a year
lookup.
`value` is an int, containing the looked-up year.
If `iso_year` is True, return bounds for ISO-8601 week-numbering years.
"""
if iso_year:
first = datetime.datetime.fromisocalendar(value, 1, 1)
second = (
datetime.datetime.fromisocalendar(value + 1, 1, 1) -
datetime.timedelta(microseconds=1)
)
else:
first = datetime.datetime(value, 1, 1)
second = datetime.datetime(value, 12, 31, 23, 59, 59, 999999)
if settings.USE_TZ:
tz = timezone.get_current_timezone()
first = timezone.make_aware(first, tz)
second = timezone.make_aware(second, tz)
first = self.adapt_datetimefield_value(first)
second = self.adapt_datetimefield_value(second)
return [first, second]
def get_db_converters(self, expression):
"""
Return a list of functions needed to convert field data.
Some field types on some backends do not provide data in the correct
format, this is the hook for converter functions.
"""
return []
def convert_durationfield_value(self, value, expression, connection):
if value is not None:
return datetime.timedelta(0, 0, value)
def check_expression_support(self, expression):
"""
Check that the backend supports the provided expression.
This is used on specific backends to rule out known expressions
that have problematic or nonexistent implementations. If the
expression has a known problem, the backend should raise
NotSupportedError.
"""
pass
def conditional_expression_supported_in_where_clause(self, expression):
"""
Return True, if the conditional expression is supported in the WHERE
clause.
"""
return True
def combine_expression(self, connector, sub_expressions):
"""
Combine a list of subexpressions into a single expression, using
the provided connecting operator. This is required because operators
can vary between backends (e.g., Oracle with %% and &) and between
subexpression types (e.g., date expressions).
"""
conn = ' %s ' % connector
return conn.join(sub_expressions)
def combine_duration_expression(self, connector, sub_expressions):
return self.combine_expression(connector, sub_expressions)
def binary_placeholder_sql(self, value):
"""
Some backends require special syntax to insert binary content (MySQL
for example uses '_binary %s').
"""
return '%s'
def modify_insert_params(self, placeholder, params):
"""
Allow modification of insert parameters. Needed for Oracle Spatial
backend due to #10888.
"""
return params
def integer_field_range(self, internal_type):
"""
Given an integer field internal type (e.g. 'PositiveIntegerField'),
return a tuple of the (min_value, max_value) form representing the
range of the column type bound to the field.
"""
return self.integer_field_ranges[internal_type]
def subtract_temporals(self, internal_type, lhs, rhs):
if self.connection.features.supports_temporal_subtraction:
lhs_sql, lhs_params = lhs
rhs_sql, rhs_params = rhs
return '(%s - %s)' % (lhs_sql, rhs_sql), (*lhs_params, *rhs_params)
raise NotSupportedError("This backend does not support %s subtraction." % internal_type)
def window_frame_start(self, start):
if isinstance(start, int):
if start < 0:
return '%d %s' % (abs(start), self.PRECEDING)
elif start == 0:
return self.CURRENT_ROW
elif start is None:
return self.UNBOUNDED_PRECEDING
raise ValueError("start argument must be a negative integer, zero, or None, but got '%s'." % start)
def window_frame_end(self, end):
if isinstance(end, int):
if end == 0:
return self.CURRENT_ROW
elif end > 0:
return '%d %s' % (end, self.FOLLOWING)
elif end is None:
return self.UNBOUNDED_FOLLOWING
raise ValueError("end argument must be a positive integer, zero, or None, but got '%s'." % end)
def window_frame_rows_start_end(self, start=None, end=None):
"""
Return SQL for start and end points in an OVER clause window frame.
"""
if not self.connection.features.supports_over_clause:
raise NotSupportedError('This backend does not support window expressions.')
return self.window_frame_start(start), self.window_frame_end(end)
def window_frame_range_start_end(self, start=None, end=None):
start_, end_ = self.window_frame_rows_start_end(start, end)
if (
self.connection.features.only_supports_unbounded_with_preceding_and_following and
((start and start < 0) or (end and end > 0))
):
raise NotSupportedError(
'%s only supports UNBOUNDED together with PRECEDING and '
'FOLLOWING.' % self.connection.display_name
)
return start_, end_
def explain_query_prefix(self, format=None, **options):
if not self.connection.features.supports_explaining_query_execution:
raise NotSupportedError('This backend does not support explaining query execution.')
if format:
supported_formats = self.connection.features.supported_explain_formats
normalized_format = format.upper()
if normalized_format not in supported_formats:
msg = '%s is not a recognized format.' % normalized_format
if supported_formats:
msg += ' Allowed formats: %s' % ', '.join(sorted(supported_formats))
raise ValueError(msg)
if options:
raise ValueError('Unknown options: %s' % ', '.join(sorted(options.keys())))
return self.explain_prefix
def insert_statement(self, on_conflict=None):
return 'INSERT INTO'
def on_conflict_suffix_sql(self, fields, on_conflict, update_fields, unique_fields):
return ''
|
8c23310998a90b1986e9c962dc967c211e46a36ec01e4c4e3eaba6576c6e6b74 | import logging
from datetime import datetime
from django.db.backends.ddl_references import (
Columns, Expressions, ForeignKeyName, IndexName, Statement, Table,
)
from django.db.backends.utils import names_digest, split_identifier
from django.db.models import Deferrable, Index
from django.db.models.sql import Query
from django.db.transaction import TransactionManagementError, atomic
from django.utils import timezone
logger = logging.getLogger('django.db.backends.schema')
def _is_relevant_relation(relation, altered_field):
"""
When altering the given field, must constraints on its model from the given
relation be temporarily dropped?
"""
field = relation.field
if field.many_to_many:
# M2M reverse field
return False
if altered_field.primary_key and field.to_fields == [None]:
# Foreign key constraint on the primary key, which is being altered.
return True
# Is the constraint targeting the field being altered?
return altered_field.name in field.to_fields
def _all_related_fields(model):
return model._meta._get_fields(
forward=False, reverse=True, include_hidden=True, include_parents=False,
)
def _related_non_m2m_objects(old_field, new_field):
# Filter out m2m objects from reverse relations.
# Return (old_relation, new_relation) tuples.
related_fields = zip(
(obj for obj in _all_related_fields(old_field.model) if _is_relevant_relation(obj, old_field)),
(obj for obj in _all_related_fields(new_field.model) if _is_relevant_relation(obj, new_field)),
)
for old_rel, new_rel in related_fields:
yield old_rel, new_rel
yield from _related_non_m2m_objects(
old_rel.remote_field,
new_rel.remote_field,
)
class BaseDatabaseSchemaEditor:
"""
This class and its subclasses are responsible for emitting schema-changing
statements to the databases - model creation/removal/alteration, field
renaming, index fiddling, and so on.
"""
# Overrideable SQL templates
sql_create_table = "CREATE TABLE %(table)s (%(definition)s)"
sql_rename_table = "ALTER TABLE %(old_table)s RENAME TO %(new_table)s"
sql_retablespace_table = "ALTER TABLE %(table)s SET TABLESPACE %(new_tablespace)s"
sql_delete_table = "DROP TABLE %(table)s CASCADE"
sql_create_column = "ALTER TABLE %(table)s ADD COLUMN %(column)s %(definition)s"
sql_alter_column = "ALTER TABLE %(table)s %(changes)s"
sql_alter_column_type = "ALTER COLUMN %(column)s TYPE %(type)s"
sql_alter_column_null = "ALTER COLUMN %(column)s DROP NOT NULL"
sql_alter_column_not_null = "ALTER COLUMN %(column)s SET NOT NULL"
sql_alter_column_default = "ALTER COLUMN %(column)s SET DEFAULT %(default)s"
sql_alter_column_no_default = "ALTER COLUMN %(column)s DROP DEFAULT"
sql_alter_column_no_default_null = sql_alter_column_no_default
sql_alter_column_collate = "ALTER COLUMN %(column)s TYPE %(type)s%(collation)s"
sql_delete_column = "ALTER TABLE %(table)s DROP COLUMN %(column)s CASCADE"
sql_rename_column = "ALTER TABLE %(table)s RENAME COLUMN %(old_column)s TO %(new_column)s"
sql_update_with_default = "UPDATE %(table)s SET %(column)s = %(default)s WHERE %(column)s IS NULL"
sql_unique_constraint = "UNIQUE (%(columns)s)%(deferrable)s"
sql_check_constraint = "CHECK (%(check)s)"
sql_delete_constraint = "ALTER TABLE %(table)s DROP CONSTRAINT %(name)s"
sql_constraint = "CONSTRAINT %(name)s %(constraint)s"
sql_create_check = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s CHECK (%(check)s)"
sql_delete_check = sql_delete_constraint
sql_create_unique = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s UNIQUE (%(columns)s)%(deferrable)s"
sql_delete_unique = sql_delete_constraint
sql_create_fk = (
"ALTER TABLE %(table)s ADD CONSTRAINT %(name)s FOREIGN KEY (%(column)s) "
"REFERENCES %(to_table)s (%(to_column)s)%(deferrable)s"
)
sql_create_inline_fk = None
sql_create_column_inline_fk = None
sql_delete_fk = sql_delete_constraint
sql_create_index = "CREATE INDEX %(name)s ON %(table)s (%(columns)s)%(include)s%(extra)s%(condition)s"
sql_create_unique_index = "CREATE UNIQUE INDEX %(name)s ON %(table)s (%(columns)s)%(include)s%(condition)s"
sql_delete_index = "DROP INDEX %(name)s"
sql_create_pk = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s PRIMARY KEY (%(columns)s)"
sql_delete_pk = sql_delete_constraint
sql_delete_procedure = 'DROP PROCEDURE %(procedure)s'
def __init__(self, connection, collect_sql=False, atomic=True):
self.connection = connection
self.collect_sql = collect_sql
if self.collect_sql:
self.collected_sql = []
self.atomic_migration = self.connection.features.can_rollback_ddl and atomic
# State-managing methods
def __enter__(self):
self.deferred_sql = []
if self.atomic_migration:
self.atomic = atomic(self.connection.alias)
self.atomic.__enter__()
return self
def __exit__(self, exc_type, exc_value, traceback):
if exc_type is None:
for sql in self.deferred_sql:
self.execute(sql)
if self.atomic_migration:
self.atomic.__exit__(exc_type, exc_value, traceback)
# Core utility functions
def execute(self, sql, params=()):
"""Execute the given SQL statement, with optional parameters."""
# Don't perform the transactional DDL check if SQL is being collected
# as it's not going to be executed anyway.
if not self.collect_sql and self.connection.in_atomic_block and not self.connection.features.can_rollback_ddl:
raise TransactionManagementError(
"Executing DDL statements while in a transaction on databases "
"that can't perform a rollback is prohibited."
)
# Account for non-string statement objects.
sql = str(sql)
# Log the command we're running, then run it
logger.debug("%s; (params %r)", sql, params, extra={'params': params, 'sql': sql})
if self.collect_sql:
ending = "" if sql.rstrip().endswith(";") else ";"
if params is not None:
self.collected_sql.append((sql % tuple(map(self.quote_value, params))) + ending)
else:
self.collected_sql.append(sql + ending)
else:
with self.connection.cursor() as cursor:
cursor.execute(sql, params)
def quote_name(self, name):
return self.connection.ops.quote_name(name)
def table_sql(self, model):
"""Take a model and return its table definition."""
# Add any unique_togethers (always deferred, as some fields might be
# created afterward, like geometry fields with some backends).
for field_names in model._meta.unique_together:
fields = [model._meta.get_field(field) for field in field_names]
self.deferred_sql.append(self._create_unique_sql(model, fields))
# Create column SQL, add FK deferreds if needed.
column_sqls = []
params = []
for field in model._meta.local_fields:
# SQL.
definition, extra_params = self.column_sql(model, field)
if definition is None:
continue
# Check constraints can go on the column SQL here.
db_params = field.db_parameters(connection=self.connection)
if db_params['check']:
definition += ' ' + self.sql_check_constraint % db_params
# Autoincrement SQL (for backends with inline variant).
col_type_suffix = field.db_type_suffix(connection=self.connection)
if col_type_suffix:
definition += ' %s' % col_type_suffix
params.extend(extra_params)
# FK.
if field.remote_field and field.db_constraint:
to_table = field.remote_field.model._meta.db_table
to_column = field.remote_field.model._meta.get_field(field.remote_field.field_name).column
if self.sql_create_inline_fk:
definition += ' ' + self.sql_create_inline_fk % {
'to_table': self.quote_name(to_table),
'to_column': self.quote_name(to_column),
}
elif self.connection.features.supports_foreign_keys:
self.deferred_sql.append(self._create_fk_sql(model, field, '_fk_%(to_table)s_%(to_column)s'))
# Add the SQL to our big list.
column_sqls.append('%s %s' % (
self.quote_name(field.column),
definition,
))
# Autoincrement SQL (for backends with post table definition
# variant).
if field.get_internal_type() in ('AutoField', 'BigAutoField', 'SmallAutoField'):
autoinc_sql = self.connection.ops.autoinc_sql(model._meta.db_table, field.column)
if autoinc_sql:
self.deferred_sql.extend(autoinc_sql)
constraints = [constraint.constraint_sql(model, self) for constraint in model._meta.constraints]
sql = self.sql_create_table % {
'table': self.quote_name(model._meta.db_table),
'definition': ', '.join(constraint for constraint in (*column_sqls, *constraints) if constraint),
}
if model._meta.db_tablespace:
tablespace_sql = self.connection.ops.tablespace_sql(model._meta.db_tablespace)
if tablespace_sql:
sql += ' ' + tablespace_sql
return sql, params
# Field <-> database mapping functions
def _iter_column_sql(self, column_db_type, params, model, field, include_default):
yield column_db_type
collation = getattr(field, 'db_collation', None)
if collation:
yield self._collate_sql(collation)
# Work out nullability.
null = field.null
# Include a default value, if requested.
include_default = (
include_default and
not self.skip_default(field) and
# Don't include a default value if it's a nullable field and the
# default cannot be dropped in the ALTER COLUMN statement (e.g.
# MySQL longtext and longblob).
not (null and self.skip_default_on_alter(field))
)
if include_default:
default_value = self.effective_default(field)
if default_value is not None:
column_default = 'DEFAULT ' + self._column_default_sql(field)
if self.connection.features.requires_literal_defaults:
# Some databases can't take defaults as a parameter (Oracle).
# If this is the case, the individual schema backend should
# implement prepare_default().
yield column_default % self.prepare_default(default_value)
else:
yield column_default
params.append(default_value)
# Oracle treats the empty string ('') as null, so coerce the null
# option whenever '' is a possible value.
if (field.empty_strings_allowed and not field.primary_key and
self.connection.features.interprets_empty_strings_as_nulls):
null = True
if not null:
yield 'NOT NULL'
elif not self.connection.features.implied_column_null:
yield 'NULL'
if field.primary_key:
yield 'PRIMARY KEY'
elif field.unique:
yield 'UNIQUE'
# Optionally add the tablespace if it's an implicitly indexed column.
tablespace = field.db_tablespace or model._meta.db_tablespace
if tablespace and self.connection.features.supports_tablespaces and field.unique:
yield self.connection.ops.tablespace_sql(tablespace, inline=True)
def column_sql(self, model, field, include_default=False):
"""
Return the column definition for a field. The field must already have
had set_attributes_from_name() called.
"""
# Get the column's type and use that as the basis of the SQL.
db_params = field.db_parameters(connection=self.connection)
column_db_type = db_params['type']
# Check for fields that aren't actually columns (e.g. M2M).
if column_db_type is None:
return None, None
params = []
return ' '.join(
# This appends to the params being returned.
self._iter_column_sql(column_db_type, params, model, field, include_default)
), params
def skip_default(self, field):
"""
Some backends don't accept default values for certain columns types
(i.e. MySQL longtext and longblob).
"""
return False
def skip_default_on_alter(self, field):
"""
Some backends don't accept default values for certain columns types
(i.e. MySQL longtext and longblob) in the ALTER COLUMN statement.
"""
return False
def prepare_default(self, value):
"""
Only used for backends which have requires_literal_defaults feature
"""
raise NotImplementedError(
'subclasses of BaseDatabaseSchemaEditor for backends which have '
'requires_literal_defaults must provide a prepare_default() method'
)
def _column_default_sql(self, field):
"""
Return the SQL to use in a DEFAULT clause. The resulting string should
contain a '%s' placeholder for a default value.
"""
return '%s'
@staticmethod
def _effective_default(field):
# This method allows testing its logic without a connection.
if field.has_default():
default = field.get_default()
elif not field.null and field.blank and field.empty_strings_allowed:
if field.get_internal_type() == "BinaryField":
default = b''
else:
default = ''
elif getattr(field, 'auto_now', False) or getattr(field, 'auto_now_add', False):
internal_type = field.get_internal_type()
if internal_type == 'DateTimeField':
default = timezone.now()
else:
default = datetime.now()
if internal_type == 'DateField':
default = default.date()
elif internal_type == 'TimeField':
default = default.time()
else:
default = None
return default
def effective_default(self, field):
"""Return a field's effective database default value."""
return field.get_db_prep_save(self._effective_default(field), self.connection)
def quote_value(self, value):
"""
Return a quoted version of the value so it's safe to use in an SQL
string. This is not safe against injection from user code; it is
intended only for use in making SQL scripts or preparing default values
for particularly tricky backends (defaults are not user-defined, though,
so this is safe).
"""
raise NotImplementedError()
# Actions
def create_model(self, model):
"""
Create a table and any accompanying indexes or unique constraints for
the given `model`.
"""
sql, params = self.table_sql(model)
# Prevent using [] as params, in the case a literal '%' is used in the definition
self.execute(sql, params or None)
# Add any field index and index_together's (deferred as SQLite _remake_table needs it)
self.deferred_sql.extend(self._model_indexes_sql(model))
# Make M2M tables
for field in model._meta.local_many_to_many:
if field.remote_field.through._meta.auto_created:
self.create_model(field.remote_field.through)
def delete_model(self, model):
"""Delete a model from the database."""
# Handle auto-created intermediary models
for field in model._meta.local_many_to_many:
if field.remote_field.through._meta.auto_created:
self.delete_model(field.remote_field.through)
# Delete the table
self.execute(self.sql_delete_table % {
"table": self.quote_name(model._meta.db_table),
})
# Remove all deferred statements referencing the deleted table.
for sql in list(self.deferred_sql):
if isinstance(sql, Statement) and sql.references_table(model._meta.db_table):
self.deferred_sql.remove(sql)
def add_index(self, model, index):
"""Add an index on a model."""
if (
index.contains_expressions and
not self.connection.features.supports_expression_indexes
):
return None
# Index.create_sql returns interpolated SQL which makes params=None a
# necessity to avoid escaping attempts on execution.
self.execute(index.create_sql(model, self), params=None)
def remove_index(self, model, index):
"""Remove an index from a model."""
if (
index.contains_expressions and
not self.connection.features.supports_expression_indexes
):
return None
self.execute(index.remove_sql(model, self))
def add_constraint(self, model, constraint):
"""Add a constraint to a model."""
sql = constraint.create_sql(model, self)
if sql:
# Constraint.create_sql returns interpolated SQL which makes
# params=None a necessity to avoid escaping attempts on execution.
self.execute(sql, params=None)
def remove_constraint(self, model, constraint):
"""Remove a constraint from a model."""
sql = constraint.remove_sql(model, self)
if sql:
self.execute(sql)
def alter_unique_together(self, model, old_unique_together, new_unique_together):
"""
Deal with a model changing its unique_together. The input
unique_togethers must be doubly-nested, not the single-nested
["foo", "bar"] format.
"""
olds = {tuple(fields) for fields in old_unique_together}
news = {tuple(fields) for fields in new_unique_together}
# Deleted uniques
for fields in olds.difference(news):
self._delete_composed_index(model, fields, {'unique': True}, self.sql_delete_unique)
# Created uniques
for field_names in news.difference(olds):
fields = [model._meta.get_field(field) for field in field_names]
self.execute(self._create_unique_sql(model, fields))
def alter_index_together(self, model, old_index_together, new_index_together):
"""
Deal with a model changing its index_together. The input
index_togethers must be doubly-nested, not the single-nested
["foo", "bar"] format.
"""
olds = {tuple(fields) for fields in old_index_together}
news = {tuple(fields) for fields in new_index_together}
# Deleted indexes
for fields in olds.difference(news):
self._delete_composed_index(
model,
fields,
{'index': True, 'unique': False},
self.sql_delete_index,
)
# Created indexes
for field_names in news.difference(olds):
fields = [model._meta.get_field(field) for field in field_names]
self.execute(self._create_index_sql(model, fields=fields, suffix='_idx'))
def _delete_composed_index(self, model, fields, constraint_kwargs, sql):
meta_constraint_names = {constraint.name for constraint in model._meta.constraints}
meta_index_names = {constraint.name for constraint in model._meta.indexes}
columns = [model._meta.get_field(field).column for field in fields]
constraint_names = self._constraint_names(
model, columns, exclude=meta_constraint_names | meta_index_names,
**constraint_kwargs
)
if len(constraint_names) != 1:
raise ValueError("Found wrong number (%s) of constraints for %s(%s)" % (
len(constraint_names),
model._meta.db_table,
", ".join(columns),
))
self.execute(self._delete_constraint_sql(sql, model, constraint_names[0]))
def alter_db_table(self, model, old_db_table, new_db_table):
"""Rename the table a model points to."""
if (old_db_table == new_db_table or
(self.connection.features.ignores_table_name_case and
old_db_table.lower() == new_db_table.lower())):
return
self.execute(self.sql_rename_table % {
"old_table": self.quote_name(old_db_table),
"new_table": self.quote_name(new_db_table),
})
# Rename all references to the old table name.
for sql in self.deferred_sql:
if isinstance(sql, Statement):
sql.rename_table_references(old_db_table, new_db_table)
def alter_db_tablespace(self, model, old_db_tablespace, new_db_tablespace):
"""Move a model's table between tablespaces."""
self.execute(self.sql_retablespace_table % {
"table": self.quote_name(model._meta.db_table),
"old_tablespace": self.quote_name(old_db_tablespace),
"new_tablespace": self.quote_name(new_db_tablespace),
})
def add_field(self, model, field):
"""
Create a field on a model. Usually involves adding a column, but may
involve adding a table instead (for M2M fields).
"""
# Special-case implicit M2M tables
if field.many_to_many and field.remote_field.through._meta.auto_created:
return self.create_model(field.remote_field.through)
# Get the column's definition
definition, params = self.column_sql(model, field, include_default=True)
# It might not actually have a column behind it
if definition is None:
return
# Check constraints can go on the column SQL here
db_params = field.db_parameters(connection=self.connection)
if db_params['check']:
definition += " " + self.sql_check_constraint % db_params
if field.remote_field and self.connection.features.supports_foreign_keys and field.db_constraint:
constraint_suffix = '_fk_%(to_table)s_%(to_column)s'
# Add FK constraint inline, if supported.
if self.sql_create_column_inline_fk:
to_table = field.remote_field.model._meta.db_table
to_column = field.remote_field.model._meta.get_field(field.remote_field.field_name).column
namespace, _ = split_identifier(model._meta.db_table)
definition += " " + self.sql_create_column_inline_fk % {
'name': self._fk_constraint_name(model, field, constraint_suffix),
'namespace': '%s.' % self.quote_name(namespace) if namespace else '',
'column': self.quote_name(field.column),
'to_table': self.quote_name(to_table),
'to_column': self.quote_name(to_column),
'deferrable': self.connection.ops.deferrable_sql()
}
# Otherwise, add FK constraints later.
else:
self.deferred_sql.append(self._create_fk_sql(model, field, constraint_suffix))
# Build the SQL and run it
sql = self.sql_create_column % {
"table": self.quote_name(model._meta.db_table),
"column": self.quote_name(field.column),
"definition": definition,
}
self.execute(sql, params)
# Drop the default if we need to
# (Django usually does not use in-database defaults)
if not self.skip_default_on_alter(field) and self.effective_default(field) is not None:
changes_sql, params = self._alter_column_default_sql(model, None, field, drop=True)
sql = self.sql_alter_column % {
"table": self.quote_name(model._meta.db_table),
"changes": changes_sql,
}
self.execute(sql, params)
# Add an index, if required
self.deferred_sql.extend(self._field_indexes_sql(model, field))
# Reset connection if required
if self.connection.features.connection_persists_old_columns:
self.connection.close()
def remove_field(self, model, field):
"""
Remove a field from a model. Usually involves deleting a column,
but for M2Ms may involve deleting a table.
"""
# Special-case implicit M2M tables
if field.many_to_many and field.remote_field.through._meta.auto_created:
return self.delete_model(field.remote_field.through)
# It might not actually have a column behind it
if field.db_parameters(connection=self.connection)['type'] is None:
return
# Drop any FK constraints, MySQL requires explicit deletion
if field.remote_field:
fk_names = self._constraint_names(model, [field.column], foreign_key=True)
for fk_name in fk_names:
self.execute(self._delete_fk_sql(model, fk_name))
# Delete the column
sql = self.sql_delete_column % {
"table": self.quote_name(model._meta.db_table),
"column": self.quote_name(field.column),
}
self.execute(sql)
# Reset connection if required
if self.connection.features.connection_persists_old_columns:
self.connection.close()
# Remove all deferred statements referencing the deleted column.
for sql in list(self.deferred_sql):
if isinstance(sql, Statement) and sql.references_column(model._meta.db_table, field.column):
self.deferred_sql.remove(sql)
def alter_field(self, model, old_field, new_field, strict=False):
"""
Allow a field's type, uniqueness, nullability, default, column,
constraints, etc. to be modified.
`old_field` is required to compute the necessary changes.
If `strict` is True, raise errors if the old column does not match
`old_field` precisely.
"""
if not self._field_should_be_altered(old_field, new_field):
return
# Ensure this field is even column-based
old_db_params = old_field.db_parameters(connection=self.connection)
old_type = old_db_params['type']
new_db_params = new_field.db_parameters(connection=self.connection)
new_type = new_db_params['type']
if ((old_type is None and old_field.remote_field is None) or
(new_type is None and new_field.remote_field is None)):
raise ValueError(
"Cannot alter field %s into %s - they do not properly define "
"db_type (are you using a badly-written custom field?)" %
(old_field, new_field),
)
elif old_type is None and new_type is None and (
old_field.remote_field.through and new_field.remote_field.through and
old_field.remote_field.through._meta.auto_created and
new_field.remote_field.through._meta.auto_created):
return self._alter_many_to_many(model, old_field, new_field, strict)
elif old_type is None and new_type is None and (
old_field.remote_field.through and new_field.remote_field.through and
not old_field.remote_field.through._meta.auto_created and
not new_field.remote_field.through._meta.auto_created):
# Both sides have through models; this is a no-op.
return
elif old_type is None or new_type is None:
raise ValueError(
"Cannot alter field %s into %s - they are not compatible types "
"(you cannot alter to or from M2M fields, or add or remove "
"through= on M2M fields)" % (old_field, new_field)
)
self._alter_field(model, old_field, new_field, old_type, new_type,
old_db_params, new_db_params, strict)
def _alter_field(self, model, old_field, new_field, old_type, new_type,
old_db_params, new_db_params, strict=False):
"""Perform a "physical" (non-ManyToMany) field update."""
# Drop any FK constraints, we'll remake them later
fks_dropped = set()
if (
self.connection.features.supports_foreign_keys and
old_field.remote_field and
old_field.db_constraint
):
fk_names = self._constraint_names(model, [old_field.column], foreign_key=True)
if strict and len(fk_names) != 1:
raise ValueError("Found wrong number (%s) of foreign key constraints for %s.%s" % (
len(fk_names),
model._meta.db_table,
old_field.column,
))
for fk_name in fk_names:
fks_dropped.add((old_field.column,))
self.execute(self._delete_fk_sql(model, fk_name))
# Has unique been removed?
if old_field.unique and (not new_field.unique or self._field_became_primary_key(old_field, new_field)):
# Find the unique constraint for this field
meta_constraint_names = {constraint.name for constraint in model._meta.constraints}
constraint_names = self._constraint_names(
model, [old_field.column], unique=True, primary_key=False,
exclude=meta_constraint_names,
)
if strict and len(constraint_names) != 1:
raise ValueError("Found wrong number (%s) of unique constraints for %s.%s" % (
len(constraint_names),
model._meta.db_table,
old_field.column,
))
for constraint_name in constraint_names:
self.execute(self._delete_unique_sql(model, constraint_name))
# Drop incoming FK constraints if the field is a primary key or unique,
# which might be a to_field target, and things are going to change.
drop_foreign_keys = (
self.connection.features.supports_foreign_keys and (
(old_field.primary_key and new_field.primary_key) or
(old_field.unique and new_field.unique)
) and old_type != new_type
)
if drop_foreign_keys:
# '_meta.related_field' also contains M2M reverse fields, these
# will be filtered out
for _old_rel, new_rel in _related_non_m2m_objects(old_field, new_field):
rel_fk_names = self._constraint_names(
new_rel.related_model, [new_rel.field.column], foreign_key=True
)
for fk_name in rel_fk_names:
self.execute(self._delete_fk_sql(new_rel.related_model, fk_name))
# Removed an index? (no strict check, as multiple indexes are possible)
# Remove indexes if db_index switched to False or a unique constraint
# will now be used in lieu of an index. The following lines from the
# truth table show all True cases; the rest are False:
#
# old_field.db_index | old_field.unique | new_field.db_index | new_field.unique
# ------------------------------------------------------------------------------
# True | False | False | False
# True | False | False | True
# True | False | True | True
if old_field.db_index and not old_field.unique and (not new_field.db_index or new_field.unique):
# Find the index for this field
meta_index_names = {index.name for index in model._meta.indexes}
# Retrieve only BTREE indexes since this is what's created with
# db_index=True.
index_names = self._constraint_names(
model, [old_field.column], index=True, type_=Index.suffix,
exclude=meta_index_names,
)
for index_name in index_names:
# The only way to check if an index was created with
# db_index=True or with Index(['field'], name='foo')
# is to look at its name (refs #28053).
self.execute(self._delete_index_sql(model, index_name))
# Change check constraints?
if old_db_params['check'] != new_db_params['check'] and old_db_params['check']:
meta_constraint_names = {constraint.name for constraint in model._meta.constraints}
constraint_names = self._constraint_names(
model, [old_field.column], check=True,
exclude=meta_constraint_names,
)
if strict and len(constraint_names) != 1:
raise ValueError("Found wrong number (%s) of check constraints for %s.%s" % (
len(constraint_names),
model._meta.db_table,
old_field.column,
))
for constraint_name in constraint_names:
self.execute(self._delete_check_sql(model, constraint_name))
# Have they renamed the column?
if old_field.column != new_field.column:
self.execute(self._rename_field_sql(model._meta.db_table, old_field, new_field, new_type))
# Rename all references to the renamed column.
for sql in self.deferred_sql:
if isinstance(sql, Statement):
sql.rename_column_references(model._meta.db_table, old_field.column, new_field.column)
# Next, start accumulating actions to do
actions = []
null_actions = []
post_actions = []
# Collation change?
old_collation = getattr(old_field, 'db_collation', None)
new_collation = getattr(new_field, 'db_collation', None)
if old_collation != new_collation:
# Collation change handles also a type change.
fragment = self._alter_column_collation_sql(model, new_field, new_type, new_collation)
actions.append(fragment)
# Type change?
elif old_type != new_type:
fragment, other_actions = self._alter_column_type_sql(model, old_field, new_field, new_type)
actions.append(fragment)
post_actions.extend(other_actions)
# When changing a column NULL constraint to NOT NULL with a given
# default value, we need to perform 4 steps:
# 1. Add a default for new incoming writes
# 2. Update existing NULL rows with new default
# 3. Replace NULL constraint with NOT NULL
# 4. Drop the default again.
# Default change?
needs_database_default = False
if old_field.null and not new_field.null:
old_default = self.effective_default(old_field)
new_default = self.effective_default(new_field)
if (
not self.skip_default_on_alter(new_field) and
old_default != new_default and
new_default is not None
):
needs_database_default = True
actions.append(self._alter_column_default_sql(model, old_field, new_field))
# Nullability change?
if old_field.null != new_field.null:
fragment = self._alter_column_null_sql(model, old_field, new_field)
if fragment:
null_actions.append(fragment)
# Only if we have a default and there is a change from NULL to NOT NULL
four_way_default_alteration = (
new_field.has_default() and
(old_field.null and not new_field.null)
)
if actions or null_actions:
if not four_way_default_alteration:
# If we don't have to do a 4-way default alteration we can
# directly run a (NOT) NULL alteration
actions = actions + null_actions
# Combine actions together if we can (e.g. postgres)
if self.connection.features.supports_combined_alters and actions:
sql, params = tuple(zip(*actions))
actions = [(", ".join(sql), sum(params, []))]
# Apply those actions
for sql, params in actions:
self.execute(
self.sql_alter_column % {
"table": self.quote_name(model._meta.db_table),
"changes": sql,
},
params,
)
if four_way_default_alteration:
# Update existing rows with default value
self.execute(
self.sql_update_with_default % {
"table": self.quote_name(model._meta.db_table),
"column": self.quote_name(new_field.column),
"default": "%s",
},
[new_default],
)
# Since we didn't run a NOT NULL change before we need to do it
# now
for sql, params in null_actions:
self.execute(
self.sql_alter_column % {
"table": self.quote_name(model._meta.db_table),
"changes": sql,
},
params,
)
if post_actions:
for sql, params in post_actions:
self.execute(sql, params)
# If primary_key changed to False, delete the primary key constraint.
if old_field.primary_key and not new_field.primary_key:
self._delete_primary_key(model, strict)
# Added a unique?
if self._unique_should_be_added(old_field, new_field):
self.execute(self._create_unique_sql(model, [new_field]))
# Added an index? Add an index if db_index switched to True or a unique
# constraint will no longer be used in lieu of an index. The following
# lines from the truth table show all True cases; the rest are False:
#
# old_field.db_index | old_field.unique | new_field.db_index | new_field.unique
# ------------------------------------------------------------------------------
# False | False | True | False
# False | True | True | False
# True | True | True | False
if (not old_field.db_index or old_field.unique) and new_field.db_index and not new_field.unique:
self.execute(self._create_index_sql(model, fields=[new_field]))
# Type alteration on primary key? Then we need to alter the column
# referring to us.
rels_to_update = []
if drop_foreign_keys:
rels_to_update.extend(_related_non_m2m_objects(old_field, new_field))
# Changed to become primary key?
if self._field_became_primary_key(old_field, new_field):
# Make the new one
self.execute(self._create_primary_key_sql(model, new_field))
# Update all referencing columns
rels_to_update.extend(_related_non_m2m_objects(old_field, new_field))
# Handle our type alters on the other end of rels from the PK stuff above
for old_rel, new_rel in rels_to_update:
rel_db_params = new_rel.field.db_parameters(connection=self.connection)
rel_type = rel_db_params['type']
fragment, other_actions = self._alter_column_type_sql(
new_rel.related_model, old_rel.field, new_rel.field, rel_type
)
self.execute(
self.sql_alter_column % {
"table": self.quote_name(new_rel.related_model._meta.db_table),
"changes": fragment[0],
},
fragment[1],
)
for sql, params in other_actions:
self.execute(sql, params)
# Does it have a foreign key?
if (self.connection.features.supports_foreign_keys and new_field.remote_field and
(fks_dropped or not old_field.remote_field or not old_field.db_constraint) and
new_field.db_constraint):
self.execute(self._create_fk_sql(model, new_field, "_fk_%(to_table)s_%(to_column)s"))
# Rebuild FKs that pointed to us if we previously had to drop them
if drop_foreign_keys:
for _, rel in rels_to_update:
if rel.field.db_constraint:
self.execute(self._create_fk_sql(rel.related_model, rel.field, "_fk"))
# Does it have check constraints we need to add?
if old_db_params['check'] != new_db_params['check'] and new_db_params['check']:
constraint_name = self._create_index_name(model._meta.db_table, [new_field.column], suffix='_check')
self.execute(self._create_check_sql(model, constraint_name, new_db_params['check']))
# Drop the default if we need to
# (Django usually does not use in-database defaults)
if needs_database_default:
changes_sql, params = self._alter_column_default_sql(model, old_field, new_field, drop=True)
sql = self.sql_alter_column % {
"table": self.quote_name(model._meta.db_table),
"changes": changes_sql,
}
self.execute(sql, params)
# Reset connection if required
if self.connection.features.connection_persists_old_columns:
self.connection.close()
def _alter_column_null_sql(self, model, old_field, new_field):
"""
Hook to specialize column null alteration.
Return a (sql, params) fragment to set a column to null or non-null
as required by new_field, or None if no changes are required.
"""
if (
self.connection.features.interprets_empty_strings_as_nulls and
new_field.empty_strings_allowed
):
# The field is nullable in the database anyway, leave it alone.
return
else:
new_db_params = new_field.db_parameters(connection=self.connection)
sql = self.sql_alter_column_null if new_field.null else self.sql_alter_column_not_null
return (
sql % {
'column': self.quote_name(new_field.column),
'type': new_db_params['type'],
},
[],
)
def _alter_column_default_sql(self, model, old_field, new_field, drop=False):
"""
Hook to specialize column default alteration.
Return a (sql, params) fragment to add or drop (depending on the drop
argument) a default to new_field's column.
"""
new_default = self.effective_default(new_field)
default = self._column_default_sql(new_field)
params = [new_default]
if drop:
params = []
elif self.connection.features.requires_literal_defaults:
# Some databases (Oracle) can't take defaults as a parameter
# If this is the case, the SchemaEditor for that database should
# implement prepare_default().
default = self.prepare_default(new_default)
params = []
new_db_params = new_field.db_parameters(connection=self.connection)
if drop:
if new_field.null:
sql = self.sql_alter_column_no_default_null
else:
sql = self.sql_alter_column_no_default
else:
sql = self.sql_alter_column_default
return (
sql % {
'column': self.quote_name(new_field.column),
'type': new_db_params['type'],
'default': default,
},
params,
)
def _alter_column_type_sql(self, model, old_field, new_field, new_type):
"""
Hook to specialize column type alteration for different backends,
for cases when a creation type is different to an alteration type
(e.g. SERIAL in PostgreSQL, PostGIS fields).
Return a two-tuple of: an SQL fragment of (sql, params) to insert into
an ALTER TABLE statement and a list of extra (sql, params) tuples to
run once the field is altered.
"""
return (
(
self.sql_alter_column_type % {
"column": self.quote_name(new_field.column),
"type": new_type,
},
[],
),
[],
)
def _alter_column_collation_sql(self, model, new_field, new_type, new_collation):
return (
self.sql_alter_column_collate % {
'column': self.quote_name(new_field.column),
'type': new_type,
'collation': ' ' + self._collate_sql(new_collation) if new_collation else '',
},
[],
)
def _alter_many_to_many(self, model, old_field, new_field, strict):
"""Alter M2Ms to repoint their to= endpoints."""
# Rename the through table
if old_field.remote_field.through._meta.db_table != new_field.remote_field.through._meta.db_table:
self.alter_db_table(old_field.remote_field.through, old_field.remote_field.through._meta.db_table,
new_field.remote_field.through._meta.db_table)
# Repoint the FK to the other side
self.alter_field(
new_field.remote_field.through,
# We need the field that points to the target model, so we can tell alter_field to change it -
# this is m2m_reverse_field_name() (as opposed to m2m_field_name, which points to our model)
old_field.remote_field.through._meta.get_field(old_field.m2m_reverse_field_name()),
new_field.remote_field.through._meta.get_field(new_field.m2m_reverse_field_name()),
)
self.alter_field(
new_field.remote_field.through,
# for self-referential models we need to alter field from the other end too
old_field.remote_field.through._meta.get_field(old_field.m2m_field_name()),
new_field.remote_field.through._meta.get_field(new_field.m2m_field_name()),
)
def _create_index_name(self, table_name, column_names, suffix=""):
"""
Generate a unique name for an index/unique constraint.
The name is divided into 3 parts: the table name, the column names,
and a unique digest and suffix.
"""
_, table_name = split_identifier(table_name)
hash_suffix_part = '%s%s' % (names_digest(table_name, *column_names, length=8), suffix)
max_length = self.connection.ops.max_name_length() or 200
# If everything fits into max_length, use that name.
index_name = '%s_%s_%s' % (table_name, '_'.join(column_names), hash_suffix_part)
if len(index_name) <= max_length:
return index_name
# Shorten a long suffix.
if len(hash_suffix_part) > max_length / 3:
hash_suffix_part = hash_suffix_part[:max_length // 3]
other_length = (max_length - len(hash_suffix_part)) // 2 - 1
index_name = '%s_%s_%s' % (
table_name[:other_length],
'_'.join(column_names)[:other_length],
hash_suffix_part,
)
# Prepend D if needed to prevent the name from starting with an
# underscore or a number (not permitted on Oracle).
if index_name[0] == "_" or index_name[0].isdigit():
index_name = "D%s" % index_name[:-1]
return index_name
def _get_index_tablespace_sql(self, model, fields, db_tablespace=None):
if db_tablespace is None:
if len(fields) == 1 and fields[0].db_tablespace:
db_tablespace = fields[0].db_tablespace
elif model._meta.db_tablespace:
db_tablespace = model._meta.db_tablespace
if db_tablespace is not None:
return ' ' + self.connection.ops.tablespace_sql(db_tablespace)
return ''
def _index_condition_sql(self, condition):
if condition:
return ' WHERE ' + condition
return ''
def _index_include_sql(self, model, columns):
if not columns or not self.connection.features.supports_covering_indexes:
return ''
return Statement(
' INCLUDE (%(columns)s)',
columns=Columns(model._meta.db_table, columns, self.quote_name),
)
def _create_index_sql(self, model, *, fields=None, name=None, suffix='', using='',
db_tablespace=None, col_suffixes=(), sql=None, opclasses=(),
condition=None, include=None, expressions=None):
"""
Return the SQL statement to create the index for one or several fields
or expressions. `sql` can be specified if the syntax differs from the
standard (GIS indexes, ...).
"""
fields = fields or []
expressions = expressions or []
compiler = Query(model, alias_cols=False).get_compiler(
connection=self.connection,
)
tablespace_sql = self._get_index_tablespace_sql(model, fields, db_tablespace=db_tablespace)
columns = [field.column for field in fields]
sql_create_index = sql or self.sql_create_index
table = model._meta.db_table
def create_index_name(*args, **kwargs):
nonlocal name
if name is None:
name = self._create_index_name(*args, **kwargs)
return self.quote_name(name)
return Statement(
sql_create_index,
table=Table(table, self.quote_name),
name=IndexName(table, columns, suffix, create_index_name),
using=using,
columns=(
self._index_columns(table, columns, col_suffixes, opclasses)
if columns
else Expressions(table, expressions, compiler, self.quote_value)
),
extra=tablespace_sql,
condition=self._index_condition_sql(condition),
include=self._index_include_sql(model, include),
)
def _delete_index_sql(self, model, name, sql=None):
return Statement(
sql or self.sql_delete_index,
table=Table(model._meta.db_table, self.quote_name),
name=self.quote_name(name),
)
def _index_columns(self, table, columns, col_suffixes, opclasses):
return Columns(table, columns, self.quote_name, col_suffixes=col_suffixes)
def _model_indexes_sql(self, model):
"""
Return a list of all index SQL statements (field indexes,
index_together, Meta.indexes) for the specified model.
"""
if not model._meta.managed or model._meta.proxy or model._meta.swapped:
return []
output = []
for field in model._meta.local_fields:
output.extend(self._field_indexes_sql(model, field))
for field_names in model._meta.index_together:
fields = [model._meta.get_field(field) for field in field_names]
output.append(self._create_index_sql(model, fields=fields, suffix='_idx'))
for index in model._meta.indexes:
if (
not index.contains_expressions or
self.connection.features.supports_expression_indexes
):
output.append(index.create_sql(model, self))
return output
def _field_indexes_sql(self, model, field):
"""
Return a list of all index SQL statements for the specified field.
"""
output = []
if self._field_should_be_indexed(model, field):
output.append(self._create_index_sql(model, fields=[field]))
return output
def _field_should_be_altered(self, old_field, new_field):
_, old_path, old_args, old_kwargs = old_field.deconstruct()
_, new_path, new_args, new_kwargs = new_field.deconstruct()
# Don't alter when:
# - changing only a field name
# - changing an attribute that doesn't affect the schema
# - adding only a db_column and the column name is not changed
non_database_attrs = [
'blank',
'db_column',
'editable',
'error_messages',
'help_text',
'limit_choices_to',
# Database-level options are not supported, see #21961.
'on_delete',
'related_name',
'related_query_name',
'validators',
'verbose_name',
]
for attr in non_database_attrs:
old_kwargs.pop(attr, None)
new_kwargs.pop(attr, None)
return (
self.quote_name(old_field.column) != self.quote_name(new_field.column) or
(old_path, old_args, old_kwargs) != (new_path, new_args, new_kwargs)
)
def _field_should_be_indexed(self, model, field):
return field.db_index and not field.unique
def _field_became_primary_key(self, old_field, new_field):
return not old_field.primary_key and new_field.primary_key
def _unique_should_be_added(self, old_field, new_field):
return (
not new_field.primary_key and
new_field.unique and
(not old_field.unique or old_field.primary_key)
)
def _rename_field_sql(self, table, old_field, new_field, new_type):
return self.sql_rename_column % {
"table": self.quote_name(table),
"old_column": self.quote_name(old_field.column),
"new_column": self.quote_name(new_field.column),
"type": new_type,
}
def _create_fk_sql(self, model, field, suffix):
table = Table(model._meta.db_table, self.quote_name)
name = self._fk_constraint_name(model, field, suffix)
column = Columns(model._meta.db_table, [field.column], self.quote_name)
to_table = Table(field.target_field.model._meta.db_table, self.quote_name)
to_column = Columns(field.target_field.model._meta.db_table, [field.target_field.column], self.quote_name)
deferrable = self.connection.ops.deferrable_sql()
return Statement(
self.sql_create_fk,
table=table,
name=name,
column=column,
to_table=to_table,
to_column=to_column,
deferrable=deferrable,
)
def _fk_constraint_name(self, model, field, suffix):
def create_fk_name(*args, **kwargs):
return self.quote_name(self._create_index_name(*args, **kwargs))
return ForeignKeyName(
model._meta.db_table,
[field.column],
split_identifier(field.target_field.model._meta.db_table)[1],
[field.target_field.column],
suffix,
create_fk_name,
)
def _delete_fk_sql(self, model, name):
return self._delete_constraint_sql(self.sql_delete_fk, model, name)
def _deferrable_constraint_sql(self, deferrable):
if deferrable is None:
return ''
if deferrable == Deferrable.DEFERRED:
return ' DEFERRABLE INITIALLY DEFERRED'
if deferrable == Deferrable.IMMEDIATE:
return ' DEFERRABLE INITIALLY IMMEDIATE'
def _unique_sql(
self, model, fields, name, condition=None, deferrable=None,
include=None, opclasses=None, expressions=None,
):
if (
deferrable and
not self.connection.features.supports_deferrable_unique_constraints
):
return None
if condition or include or opclasses or expressions:
# Databases support conditional, covering, and functional unique
# constraints via a unique index.
sql = self._create_unique_sql(
model,
fields,
name=name,
condition=condition,
include=include,
opclasses=opclasses,
expressions=expressions,
)
if sql:
self.deferred_sql.append(sql)
return None
constraint = self.sql_unique_constraint % {
'columns': ', '.join([self.quote_name(field.column) for field in fields]),
'deferrable': self._deferrable_constraint_sql(deferrable),
}
return self.sql_constraint % {
'name': self.quote_name(name),
'constraint': constraint,
}
def _create_unique_sql(
self, model, fields, name=None, condition=None, deferrable=None,
include=None, opclasses=None, expressions=None,
):
if (
(
deferrable and
not self.connection.features.supports_deferrable_unique_constraints
) or
(condition and not self.connection.features.supports_partial_indexes) or
(include and not self.connection.features.supports_covering_indexes) or
(expressions and not self.connection.features.supports_expression_indexes)
):
return None
def create_unique_name(*args, **kwargs):
return self.quote_name(self._create_index_name(*args, **kwargs))
compiler = Query(model, alias_cols=False).get_compiler(connection=self.connection)
table = model._meta.db_table
columns = [field.column for field in fields]
if name is None:
name = IndexName(table, columns, '_uniq', create_unique_name)
else:
name = self.quote_name(name)
if condition or include or opclasses or expressions:
sql = self.sql_create_unique_index
else:
sql = self.sql_create_unique
if columns:
columns = self._index_columns(table, columns, col_suffixes=(), opclasses=opclasses)
else:
columns = Expressions(table, expressions, compiler, self.quote_value)
return Statement(
sql,
table=Table(table, self.quote_name),
name=name,
columns=columns,
condition=self._index_condition_sql(condition),
deferrable=self._deferrable_constraint_sql(deferrable),
include=self._index_include_sql(model, include),
)
def _delete_unique_sql(
self, model, name, condition=None, deferrable=None, include=None,
opclasses=None, expressions=None,
):
if (
(
deferrable and
not self.connection.features.supports_deferrable_unique_constraints
) or
(condition and not self.connection.features.supports_partial_indexes) or
(include and not self.connection.features.supports_covering_indexes) or
(expressions and not self.connection.features.supports_expression_indexes)
):
return None
if condition or include or opclasses or expressions:
sql = self.sql_delete_index
else:
sql = self.sql_delete_unique
return self._delete_constraint_sql(sql, model, name)
def _check_sql(self, name, check):
return self.sql_constraint % {
'name': self.quote_name(name),
'constraint': self.sql_check_constraint % {'check': check},
}
def _create_check_sql(self, model, name, check):
return Statement(
self.sql_create_check,
table=Table(model._meta.db_table, self.quote_name),
name=self.quote_name(name),
check=check,
)
def _delete_check_sql(self, model, name):
return self._delete_constraint_sql(self.sql_delete_check, model, name)
def _delete_constraint_sql(self, template, model, name):
return Statement(
template,
table=Table(model._meta.db_table, self.quote_name),
name=self.quote_name(name),
)
def _constraint_names(self, model, column_names=None, unique=None,
primary_key=None, index=None, foreign_key=None,
check=None, type_=None, exclude=None):
"""Return all constraint names matching the columns and conditions."""
if column_names is not None:
column_names = [
self.connection.introspection.identifier_converter(name)
for name in column_names
]
with self.connection.cursor() as cursor:
constraints = self.connection.introspection.get_constraints(cursor, model._meta.db_table)
result = []
for name, infodict in constraints.items():
if column_names is None or column_names == infodict['columns']:
if unique is not None and infodict['unique'] != unique:
continue
if primary_key is not None and infodict['primary_key'] != primary_key:
continue
if index is not None and infodict['index'] != index:
continue
if check is not None and infodict['check'] != check:
continue
if foreign_key is not None and not infodict['foreign_key']:
continue
if type_ is not None and infodict['type'] != type_:
continue
if not exclude or name not in exclude:
result.append(name)
return result
def _delete_primary_key(self, model, strict=False):
constraint_names = self._constraint_names(model, primary_key=True)
if strict and len(constraint_names) != 1:
raise ValueError('Found wrong number (%s) of PK constraints for %s' % (
len(constraint_names),
model._meta.db_table,
))
for constraint_name in constraint_names:
self.execute(self._delete_primary_key_sql(model, constraint_name))
def _create_primary_key_sql(self, model, field):
return Statement(
self.sql_create_pk,
table=Table(model._meta.db_table, self.quote_name),
name=self.quote_name(
self._create_index_name(model._meta.db_table, [field.column], suffix="_pk")
),
columns=Columns(model._meta.db_table, [field.column], self.quote_name),
)
def _delete_primary_key_sql(self, model, name):
return self._delete_constraint_sql(self.sql_delete_pk, model, name)
def _collate_sql(self, collation):
return 'COLLATE ' + self.quote_name(collation)
def remove_procedure(self, procedure_name, param_types=()):
sql = self.sql_delete_procedure % {
'procedure': self.quote_name(procedure_name),
'param_types': ','.join(param_types),
}
self.execute(sql)
|
bbcaeb798b48a39b62837cb8cb150892c8b4929fde03aa40b10e378fc4b57b46 | import os
import sys
from io import StringIO
from django.apps import apps
from django.conf import settings
from django.core import serializers
from django.db import router
from django.db.transaction import atomic
from django.utils.module_loading import import_string
# The prefix to put on the default database name when creating
# the test database.
TEST_DATABASE_PREFIX = 'test_'
class BaseDatabaseCreation:
"""
Encapsulate backend-specific differences pertaining to creation and
destruction of the test database.
"""
def __init__(self, connection):
self.connection = connection
def _nodb_cursor(self):
return self.connection._nodb_cursor()
def log(self, msg):
sys.stderr.write(msg + os.linesep)
def create_test_db(self, verbosity=1, autoclobber=False, serialize=True, keepdb=False):
"""
Create a test database, prompting the user for confirmation if the
database already exists. Return the name of the test database created.
"""
# Don't import django.core.management if it isn't needed.
from django.core.management import call_command
test_database_name = self._get_test_db_name()
if verbosity >= 1:
action = 'Creating'
if keepdb:
action = "Using existing"
self.log('%s test database for alias %s...' % (
action,
self._get_database_display_str(verbosity, test_database_name),
))
# We could skip this call if keepdb is True, but we instead
# give it the keepdb param. This is to handle the case
# where the test DB doesn't exist, in which case we need to
# create it, then just not destroy it. If we instead skip
# this, we will get an exception.
self._create_test_db(verbosity, autoclobber, keepdb)
self.connection.close()
settings.DATABASES[self.connection.alias]["NAME"] = test_database_name
self.connection.settings_dict["NAME"] = test_database_name
try:
if self.connection.settings_dict['TEST']['MIGRATE'] is False:
# Disable migrations for all apps.
old_migration_modules = settings.MIGRATION_MODULES
settings.MIGRATION_MODULES = {
app.label: None
for app in apps.get_app_configs()
}
# We report migrate messages at one level lower than that
# requested. This ensures we don't get flooded with messages during
# testing (unless you really ask to be flooded).
call_command(
'migrate',
verbosity=max(verbosity - 1, 0),
interactive=False,
database=self.connection.alias,
run_syncdb=True,
)
finally:
if self.connection.settings_dict['TEST']['MIGRATE'] is False:
settings.MIGRATION_MODULES = old_migration_modules
# We then serialize the current state of the database into a string
# and store it on the connection. This slightly horrific process is so people
# who are testing on databases without transactions or who are using
# a TransactionTestCase still get a clean database on every test run.
if serialize:
self.connection._test_serialized_contents = self.serialize_db_to_string()
call_command('createcachetable', database=self.connection.alias)
# Ensure a connection for the side effect of initializing the test database.
self.connection.ensure_connection()
if os.environ.get('RUNNING_DJANGOS_TEST_SUITE') == 'true':
self.mark_expected_failures_and_skips()
return test_database_name
def set_as_test_mirror(self, primary_settings_dict):
"""
Set this database up to be used in testing as a mirror of a primary
database whose settings are given.
"""
self.connection.settings_dict['NAME'] = primary_settings_dict['NAME']
def serialize_db_to_string(self):
"""
Serialize all data in the database into a JSON string.
Designed only for test runner usage; will not handle large
amounts of data.
"""
# Iteratively return every object for all models to serialize.
def get_objects():
from django.db.migrations.loader import MigrationLoader
loader = MigrationLoader(self.connection)
for app_config in apps.get_app_configs():
if (
app_config.models_module is not None and
app_config.label in loader.migrated_apps and
app_config.name not in settings.TEST_NON_SERIALIZED_APPS
):
for model in app_config.get_models():
if (
model._meta.can_migrate(self.connection) and
router.allow_migrate_model(self.connection.alias, model)
):
queryset = model._base_manager.using(
self.connection.alias,
).order_by(model._meta.pk.name)
yield from queryset.iterator()
# Serialize to a string
out = StringIO()
serializers.serialize("json", get_objects(), indent=None, stream=out)
return out.getvalue()
def deserialize_db_from_string(self, data):
"""
Reload the database with data from a string generated by
the serialize_db_to_string() method.
"""
data = StringIO(data)
table_names = set()
# Load data in a transaction to handle forward references and cycles.
with atomic(using=self.connection.alias):
# Disable constraint checks, because some databases (MySQL) doesn't
# support deferred checks.
with self.connection.constraint_checks_disabled():
for obj in serializers.deserialize('json', data, using=self.connection.alias):
obj.save()
table_names.add(obj.object.__class__._meta.db_table)
# Manually check for any invalid keys that might have been added,
# because constraint checks were disabled.
self.connection.check_constraints(table_names=table_names)
def _get_database_display_str(self, verbosity, database_name):
"""
Return display string for a database for use in various actions.
"""
return "'%s'%s" % (
self.connection.alias,
(" ('%s')" % database_name) if verbosity >= 2 else '',
)
def _get_test_db_name(self):
"""
Internal implementation - return the name of the test DB that will be
created. Only useful when called from create_test_db() and
_create_test_db() and when no external munging is done with the 'NAME'
settings.
"""
if self.connection.settings_dict['TEST']['NAME']:
return self.connection.settings_dict['TEST']['NAME']
return TEST_DATABASE_PREFIX + self.connection.settings_dict['NAME']
def _execute_create_test_db(self, cursor, parameters, keepdb=False):
cursor.execute('CREATE DATABASE %(dbname)s %(suffix)s' % parameters)
def _create_test_db(self, verbosity, autoclobber, keepdb=False):
"""
Internal implementation - create the test db tables.
"""
test_database_name = self._get_test_db_name()
test_db_params = {
'dbname': self.connection.ops.quote_name(test_database_name),
'suffix': self.sql_table_creation_suffix(),
}
# Create the test database and connect to it.
with self._nodb_cursor() as cursor:
try:
self._execute_create_test_db(cursor, test_db_params, keepdb)
except Exception as e:
# if we want to keep the db, then no need to do any of the below,
# just return and skip it all.
if keepdb:
return test_database_name
self.log('Got an error creating the test database: %s' % e)
if not autoclobber:
confirm = input(
"Type 'yes' if you would like to try deleting the test "
"database '%s', or 'no' to cancel: " % test_database_name)
if autoclobber or confirm == 'yes':
try:
if verbosity >= 1:
self.log('Destroying old test database for alias %s...' % (
self._get_database_display_str(verbosity, test_database_name),
))
cursor.execute('DROP DATABASE %(dbname)s' % test_db_params)
self._execute_create_test_db(cursor, test_db_params, keepdb)
except Exception as e:
self.log('Got an error recreating the test database: %s' % e)
sys.exit(2)
else:
self.log('Tests cancelled.')
sys.exit(1)
return test_database_name
def clone_test_db(self, suffix, verbosity=1, autoclobber=False, keepdb=False):
"""
Clone a test database.
"""
source_database_name = self.connection.settings_dict['NAME']
if verbosity >= 1:
action = 'Cloning test database'
if keepdb:
action = 'Using existing clone'
self.log('%s for alias %s...' % (
action,
self._get_database_display_str(verbosity, source_database_name),
))
# We could skip this call if keepdb is True, but we instead
# give it the keepdb param. See create_test_db for details.
self._clone_test_db(suffix, verbosity, keepdb)
def get_test_db_clone_settings(self, suffix):
"""
Return a modified connection settings dict for the n-th clone of a DB.
"""
# When this function is called, the test database has been created
# already and its name has been copied to settings_dict['NAME'] so
# we don't need to call _get_test_db_name.
orig_settings_dict = self.connection.settings_dict
return {**orig_settings_dict, 'NAME': '{}_{}'.format(orig_settings_dict['NAME'], suffix)}
def _clone_test_db(self, suffix, verbosity, keepdb=False):
"""
Internal implementation - duplicate the test db tables.
"""
raise NotImplementedError(
"The database backend doesn't support cloning databases. "
"Disable the option to run tests in parallel processes.")
def destroy_test_db(self, old_database_name=None, verbosity=1, keepdb=False, suffix=None):
"""
Destroy a test database, prompting the user for confirmation if the
database already exists.
"""
self.connection.close()
if suffix is None:
test_database_name = self.connection.settings_dict['NAME']
else:
test_database_name = self.get_test_db_clone_settings(suffix)['NAME']
if verbosity >= 1:
action = 'Destroying'
if keepdb:
action = 'Preserving'
self.log('%s test database for alias %s...' % (
action,
self._get_database_display_str(verbosity, test_database_name),
))
# if we want to preserve the database
# skip the actual destroying piece.
if not keepdb:
self._destroy_test_db(test_database_name, verbosity)
# Restore the original database name
if old_database_name is not None:
settings.DATABASES[self.connection.alias]["NAME"] = old_database_name
self.connection.settings_dict["NAME"] = old_database_name
def _destroy_test_db(self, test_database_name, verbosity):
"""
Internal implementation - remove the test db tables.
"""
# Remove the test database to clean up after
# ourselves. Connect to the previous database (not the test database)
# to do so, because it's not allowed to delete a database while being
# connected to it.
with self._nodb_cursor() as cursor:
cursor.execute("DROP DATABASE %s"
% self.connection.ops.quote_name(test_database_name))
def mark_expected_failures_and_skips(self):
"""
Mark tests in Django's test suite which are expected failures on this
database and test which should be skipped on this database.
"""
# Only load unittest if we're actually testing.
from unittest import expectedFailure, skip
for test_name in self.connection.features.django_test_expected_failures:
test_case_name, _, test_method_name = test_name.rpartition('.')
test_app = test_name.split('.')[0]
# Importing a test app that isn't installed raises RuntimeError.
if test_app in settings.INSTALLED_APPS:
test_case = import_string(test_case_name)
test_method = getattr(test_case, test_method_name)
setattr(test_case, test_method_name, expectedFailure(test_method))
for reason, tests in self.connection.features.django_test_skips.items():
for test_name in tests:
test_case_name, _, test_method_name = test_name.rpartition('.')
test_app = test_name.split('.')[0]
# Importing a test app that isn't installed raises RuntimeError.
if test_app in settings.INSTALLED_APPS:
test_case = import_string(test_case_name)
test_method = getattr(test_case, test_method_name)
setattr(test_case, test_method_name, skip(reason)(test_method))
def sql_table_creation_suffix(self):
"""
SQL to append to the end of the test table creation statements.
"""
return ''
def test_db_signature(self):
"""
Return a tuple with elements of self.connection.settings_dict (a
DATABASES setting value) that uniquely identify a database
accordingly to the RDBMS particularities.
"""
settings_dict = self.connection.settings_dict
return (
settings_dict['HOST'],
settings_dict['PORT'],
settings_dict['ENGINE'],
self._get_test_db_name(),
)
|
3540d716bb06583551c03195e048dcabfd139af44068dd5e359c3a3e28121416 | import operator
from django.db.backends.base.features import BaseDatabaseFeatures
from django.utils.functional import cached_property
class DatabaseFeatures(BaseDatabaseFeatures):
empty_fetchmany_value = ()
allows_group_by_pk = True
related_fields_match_type = True
# MySQL doesn't support sliced subqueries with IN/ALL/ANY/SOME.
allow_sliced_subqueries_with_in = False
has_select_for_update = True
supports_forward_references = False
supports_regex_backreferencing = False
supports_date_lookup_using_string = False
supports_timezones = False
requires_explicit_null_ordering_when_grouping = True
can_release_savepoints = True
atomic_transactions = False
can_clone_databases = True
supports_temporal_subtraction = True
supports_select_intersection = False
supports_select_difference = False
supports_slicing_ordering_in_compound = True
supports_index_on_text_field = False
supports_update_conflicts = True
create_test_procedure_without_params_sql = """
CREATE PROCEDURE test_procedure ()
BEGIN
DECLARE V_I INTEGER;
SET V_I = 1;
END;
"""
create_test_procedure_with_int_param_sql = """
CREATE PROCEDURE test_procedure (P_I INTEGER)
BEGIN
DECLARE V_I INTEGER;
SET V_I = P_I;
END;
"""
# Neither MySQL nor MariaDB support partial indexes.
supports_partial_indexes = False
# COLLATE must be wrapped in parentheses because MySQL treats COLLATE as an
# indexed expression.
collate_as_index_expression = True
supports_order_by_nulls_modifier = False
order_by_nulls_first = True
@cached_property
def test_collations(self):
charset = 'utf8'
if self.connection.mysql_is_mariadb and self.connection.mysql_version >= (10, 6):
# utf8 is an alias for utf8mb3 in MariaDB 10.6+.
charset = 'utf8mb3'
return {
'ci': f'{charset}_general_ci',
'non_default': f'{charset}_esperanto_ci',
'swedish_ci': f'{charset}_swedish_ci',
}
test_now_utc_template = 'UTC_TIMESTAMP'
@cached_property
def django_test_skips(self):
skips = {
"This doesn't work on MySQL.": {
'db_functions.comparison.test_greatest.GreatestTests.test_coalesce_workaround',
'db_functions.comparison.test_least.LeastTests.test_coalesce_workaround',
},
'Running on MySQL requires utf8mb4 encoding (#18392).': {
'model_fields.test_textfield.TextFieldTests.test_emoji',
'model_fields.test_charfield.TestCharField.test_emoji',
},
"MySQL doesn't support functional indexes on a function that "
"returns JSON": {
'schema.tests.SchemaTests.test_func_index_json_key_transform',
},
"MySQL supports multiplying and dividing DurationFields by a "
"scalar value but it's not implemented (#25287).": {
'expressions.tests.FTimeDeltaTests.test_durationfield_multiply_divide',
},
}
if 'ONLY_FULL_GROUP_BY' in self.connection.sql_mode:
skips.update({
'GROUP BY optimization does not work properly when '
'ONLY_FULL_GROUP_BY mode is enabled on MySQL, see #31331.': {
'aggregation.tests.AggregateTestCase.test_aggregation_subquery_annotation_multivalued',
'annotations.tests.NonAggregateAnnotationTestCase.test_annotation_aggregate_with_m2o',
},
})
if not self.connection.mysql_is_mariadb and self.connection.mysql_version < (8,):
skips.update({
'Casting to datetime/time is not supported by MySQL < 8.0. (#30224)': {
'aggregation.tests.AggregateTestCase.test_aggregation_default_using_time_from_python',
'aggregation.tests.AggregateTestCase.test_aggregation_default_using_datetime_from_python',
},
'MySQL < 8.0 returns string type instead of datetime/time. (#30224)': {
'aggregation.tests.AggregateTestCase.test_aggregation_default_using_time_from_database',
'aggregation.tests.AggregateTestCase.test_aggregation_default_using_datetime_from_database',
},
})
if (
self.connection.mysql_is_mariadb and
(10, 4, 3) < self.connection.mysql_version < (10, 5, 2)
):
skips.update({
'https://jira.mariadb.org/browse/MDEV-19598': {
'schema.tests.SchemaTests.test_alter_not_unique_field_to_primary_key',
},
})
if (
self.connection.mysql_is_mariadb and
(10, 4, 12) < self.connection.mysql_version < (10, 5)
):
skips.update({
'https://jira.mariadb.org/browse/MDEV-22775': {
'schema.tests.SchemaTests.test_alter_pk_with_self_referential_field',
},
})
if not self.supports_explain_analyze:
skips.update({
'MariaDB and MySQL >= 8.0.18 specific.': {
'queries.test_explain.ExplainTests.test_mysql_analyze',
},
})
return skips
@cached_property
def _mysql_storage_engine(self):
"Internal method used in Django tests. Don't rely on this from your code"
return self.connection.mysql_server_data['default_storage_engine']
@cached_property
def allows_auto_pk_0(self):
"""
Autoincrement primary key can be set to 0 if it doesn't generate new
autoincrement values.
"""
return 'NO_AUTO_VALUE_ON_ZERO' in self.connection.sql_mode
@cached_property
def update_can_self_select(self):
return self.connection.mysql_is_mariadb and self.connection.mysql_version >= (10, 3, 2)
@cached_property
def can_introspect_foreign_keys(self):
"Confirm support for introspected foreign keys"
return self._mysql_storage_engine != 'MyISAM'
@cached_property
def introspected_field_types(self):
return {
**super().introspected_field_types,
'BinaryField': 'TextField',
'BooleanField': 'IntegerField',
'DurationField': 'BigIntegerField',
'GenericIPAddressField': 'CharField',
}
@cached_property
def can_return_columns_from_insert(self):
return self.connection.mysql_is_mariadb and self.connection.mysql_version >= (10, 5, 0)
can_return_rows_from_bulk_insert = property(operator.attrgetter('can_return_columns_from_insert'))
@cached_property
def has_zoneinfo_database(self):
return self.connection.mysql_server_data['has_zoneinfo_database']
@cached_property
def is_sql_auto_is_null_enabled(self):
return self.connection.mysql_server_data['sql_auto_is_null']
@cached_property
def supports_over_clause(self):
if self.connection.mysql_is_mariadb:
return True
return self.connection.mysql_version >= (8, 0, 2)
supports_frame_range_fixed_distance = property(operator.attrgetter('supports_over_clause'))
@cached_property
def supports_column_check_constraints(self):
if self.connection.mysql_is_mariadb:
return True
return self.connection.mysql_version >= (8, 0, 16)
supports_table_check_constraints = property(operator.attrgetter('supports_column_check_constraints'))
@cached_property
def can_introspect_check_constraints(self):
if self.connection.mysql_is_mariadb:
version = self.connection.mysql_version
return version >= (10, 3, 10)
return self.connection.mysql_version >= (8, 0, 16)
@cached_property
def has_select_for_update_skip_locked(self):
if self.connection.mysql_is_mariadb:
return self.connection.mysql_version >= (10, 6)
return self.connection.mysql_version >= (8, 0, 1)
@cached_property
def has_select_for_update_nowait(self):
if self.connection.mysql_is_mariadb:
return True
return self.connection.mysql_version >= (8, 0, 1)
@cached_property
def has_select_for_update_of(self):
return not self.connection.mysql_is_mariadb and self.connection.mysql_version >= (8, 0, 1)
@cached_property
def supports_explain_analyze(self):
return self.connection.mysql_is_mariadb or self.connection.mysql_version >= (8, 0, 18)
@cached_property
def supported_explain_formats(self):
# Alias MySQL's TRADITIONAL to TEXT for consistency with other
# backends.
formats = {'JSON', 'TEXT', 'TRADITIONAL'}
if not self.connection.mysql_is_mariadb and self.connection.mysql_version >= (8, 0, 16):
formats.add('TREE')
return formats
@cached_property
def supports_transactions(self):
"""
All storage engines except MyISAM support transactions.
"""
return self._mysql_storage_engine != 'MyISAM'
@cached_property
def ignores_table_name_case(self):
return self.connection.mysql_server_data['lower_case_table_names']
@cached_property
def supports_default_in_lead_lag(self):
# To be added in https://jira.mariadb.org/browse/MDEV-12981.
return not self.connection.mysql_is_mariadb
@cached_property
def supports_json_field(self):
if self.connection.mysql_is_mariadb:
return True
return self.connection.mysql_version >= (5, 7, 8)
@cached_property
def can_introspect_json_field(self):
if self.connection.mysql_is_mariadb:
return self.supports_json_field and self.can_introspect_check_constraints
return self.supports_json_field
@cached_property
def supports_index_column_ordering(self):
return (
not self.connection.mysql_is_mariadb and
self.connection.mysql_version >= (8, 0, 1)
)
@cached_property
def supports_expression_indexes(self):
return (
not self.connection.mysql_is_mariadb and
self.connection.mysql_version >= (8, 0, 13)
)
|
e26deb61e3c364886d36be3be64ec0c1afdbeb0f83d7492668378218b7bbb705 | from collections import namedtuple
import sqlparse
from MySQLdb.constants import FIELD_TYPE
from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo as BaseFieldInfo, TableInfo,
)
from django.db.models import Index
from django.utils.datastructures import OrderedSet
FieldInfo = namedtuple('FieldInfo', BaseFieldInfo._fields + ('extra', 'is_unsigned', 'has_json_constraint'))
InfoLine = namedtuple(
'InfoLine',
'col_name data_type max_len num_prec num_scale extra column_default '
'collation is_unsigned'
)
class DatabaseIntrospection(BaseDatabaseIntrospection):
data_types_reverse = {
FIELD_TYPE.BLOB: 'TextField',
FIELD_TYPE.CHAR: 'CharField',
FIELD_TYPE.DECIMAL: 'DecimalField',
FIELD_TYPE.NEWDECIMAL: 'DecimalField',
FIELD_TYPE.DATE: 'DateField',
FIELD_TYPE.DATETIME: 'DateTimeField',
FIELD_TYPE.DOUBLE: 'FloatField',
FIELD_TYPE.FLOAT: 'FloatField',
FIELD_TYPE.INT24: 'IntegerField',
FIELD_TYPE.JSON: 'JSONField',
FIELD_TYPE.LONG: 'IntegerField',
FIELD_TYPE.LONGLONG: 'BigIntegerField',
FIELD_TYPE.SHORT: 'SmallIntegerField',
FIELD_TYPE.STRING: 'CharField',
FIELD_TYPE.TIME: 'TimeField',
FIELD_TYPE.TIMESTAMP: 'DateTimeField',
FIELD_TYPE.TINY: 'IntegerField',
FIELD_TYPE.TINY_BLOB: 'TextField',
FIELD_TYPE.MEDIUM_BLOB: 'TextField',
FIELD_TYPE.LONG_BLOB: 'TextField',
FIELD_TYPE.VAR_STRING: 'CharField',
}
def get_field_type(self, data_type, description):
field_type = super().get_field_type(data_type, description)
if 'auto_increment' in description.extra:
if field_type == 'IntegerField':
return 'AutoField'
elif field_type == 'BigIntegerField':
return 'BigAutoField'
elif field_type == 'SmallIntegerField':
return 'SmallAutoField'
if description.is_unsigned:
if field_type == 'BigIntegerField':
return 'PositiveBigIntegerField'
elif field_type == 'IntegerField':
return 'PositiveIntegerField'
elif field_type == 'SmallIntegerField':
return 'PositiveSmallIntegerField'
# JSON data type is an alias for LONGTEXT in MariaDB, use check
# constraints clauses to introspect JSONField.
if description.has_json_constraint:
return 'JSONField'
return field_type
def get_table_list(self, cursor):
"""Return a list of table and view names in the current database."""
cursor.execute("SHOW FULL TABLES")
return [TableInfo(row[0], {'BASE TABLE': 't', 'VIEW': 'v'}.get(row[1]))
for row in cursor.fetchall()]
def get_table_description(self, cursor, table_name):
"""
Return a description of the table with the DB-API cursor.description
interface."
"""
json_constraints = {}
if self.connection.mysql_is_mariadb and self.connection.features.can_introspect_json_field:
# JSON data type is an alias for LONGTEXT in MariaDB, select
# JSON_VALID() constraints to introspect JSONField.
cursor.execute("""
SELECT c.constraint_name AS column_name
FROM information_schema.check_constraints AS c
WHERE
c.table_name = %s AND
LOWER(c.check_clause) = 'json_valid(`' + LOWER(c.constraint_name) + '`)' AND
c.constraint_schema = DATABASE()
""", [table_name])
json_constraints = {row[0] for row in cursor.fetchall()}
# A default collation for the given table.
cursor.execute("""
SELECT table_collation
FROM information_schema.tables
WHERE table_schema = DATABASE()
AND table_name = %s
""", [table_name])
row = cursor.fetchone()
default_column_collation = row[0] if row else ''
# information_schema database gives more accurate results for some figures:
# - varchar length returned by cursor.description is an internal length,
# not visible length (#5725)
# - precision and scale (for decimal fields) (#5014)
# - auto_increment is not available in cursor.description
cursor.execute("""
SELECT
column_name, data_type, character_maximum_length,
numeric_precision, numeric_scale, extra, column_default,
CASE
WHEN collation_name = %s THEN NULL
ELSE collation_name
END AS collation_name,
CASE
WHEN column_type LIKE '%% unsigned' THEN 1
ELSE 0
END AS is_unsigned
FROM information_schema.columns
WHERE table_name = %s AND table_schema = DATABASE()
""", [default_column_collation, table_name])
field_info = {line[0]: InfoLine(*line) for line in cursor.fetchall()}
cursor.execute("SELECT * FROM %s LIMIT 1" % self.connection.ops.quote_name(table_name))
def to_int(i):
return int(i) if i is not None else i
fields = []
for line in cursor.description:
info = field_info[line[0]]
fields.append(FieldInfo(
*line[:3],
to_int(info.max_len) or line[3],
to_int(info.num_prec) or line[4],
to_int(info.num_scale) or line[5],
line[6],
info.column_default,
info.collation,
info.extra,
info.is_unsigned,
line[0] in json_constraints,
))
return fields
def get_sequences(self, cursor, table_name, table_fields=()):
for field_info in self.get_table_description(cursor, table_name):
if 'auto_increment' in field_info.extra:
# MySQL allows only one auto-increment column per table.
return [{'table': table_name, 'column': field_info.name}]
return []
def get_relations(self, cursor, table_name):
"""
Return a dictionary of {field_name: (field_name_other_table, other_table)}
representing all foreign keys in the given table.
"""
cursor.execute("""
SELECT column_name, referenced_column_name, referenced_table_name
FROM information_schema.key_column_usage
WHERE table_name = %s
AND table_schema = DATABASE()
AND referenced_table_name IS NOT NULL
AND referenced_column_name IS NOT NULL
""", [table_name])
return {
field_name: (other_field, other_table)
for field_name, other_field, other_table in cursor.fetchall()
}
def get_storage_engine(self, cursor, table_name):
"""
Retrieve the storage engine for a given table. Return the default
storage engine if the table doesn't exist.
"""
cursor.execute("""
SELECT engine
FROM information_schema.tables
WHERE
table_name = %s AND
table_schema = DATABASE()
""", [table_name])
result = cursor.fetchone()
if not result:
return self.connection.features._mysql_storage_engine
return result[0]
def _parse_constraint_columns(self, check_clause, columns):
check_columns = OrderedSet()
statement = sqlparse.parse(check_clause)[0]
tokens = (token for token in statement.flatten() if not token.is_whitespace)
for token in tokens:
if (
token.ttype == sqlparse.tokens.Name and
self.connection.ops.quote_name(token.value) == token.value and
token.value[1:-1] in columns
):
check_columns.add(token.value[1:-1])
return check_columns
def get_constraints(self, cursor, table_name):
"""
Retrieve any constraints or keys (unique, pk, fk, check, index) across
one or more columns.
"""
constraints = {}
# Get the actual constraint names and columns
name_query = """
SELECT kc.`constraint_name`, kc.`column_name`,
kc.`referenced_table_name`, kc.`referenced_column_name`,
c.`constraint_type`
FROM
information_schema.key_column_usage AS kc,
information_schema.table_constraints AS c
WHERE
kc.table_schema = DATABASE() AND
c.table_schema = kc.table_schema AND
c.constraint_name = kc.constraint_name AND
c.constraint_type != 'CHECK' AND
kc.table_name = %s
ORDER BY kc.`ordinal_position`
"""
cursor.execute(name_query, [table_name])
for constraint, column, ref_table, ref_column, kind in cursor.fetchall():
if constraint not in constraints:
constraints[constraint] = {
'columns': OrderedSet(),
'primary_key': kind == 'PRIMARY KEY',
'unique': kind in {'PRIMARY KEY', 'UNIQUE'},
'index': False,
'check': False,
'foreign_key': (ref_table, ref_column) if ref_column else None,
}
if self.connection.features.supports_index_column_ordering:
constraints[constraint]['orders'] = []
constraints[constraint]['columns'].add(column)
# Add check constraints.
if self.connection.features.can_introspect_check_constraints:
unnamed_constraints_index = 0
columns = {info.name for info in self.get_table_description(cursor, table_name)}
if self.connection.mysql_is_mariadb:
type_query = """
SELECT c.constraint_name, c.check_clause
FROM information_schema.check_constraints AS c
WHERE
c.constraint_schema = DATABASE() AND
c.table_name = %s
"""
else:
type_query = """
SELECT cc.constraint_name, cc.check_clause
FROM
information_schema.check_constraints AS cc,
information_schema.table_constraints AS tc
WHERE
cc.constraint_schema = DATABASE() AND
tc.table_schema = cc.constraint_schema AND
cc.constraint_name = tc.constraint_name AND
tc.constraint_type = 'CHECK' AND
tc.table_name = %s
"""
cursor.execute(type_query, [table_name])
for constraint, check_clause in cursor.fetchall():
constraint_columns = self._parse_constraint_columns(check_clause, columns)
# Ensure uniqueness of unnamed constraints. Unnamed unique
# and check columns constraints have the same name as
# a column.
if set(constraint_columns) == {constraint}:
unnamed_constraints_index += 1
constraint = '__unnamed_constraint_%s__' % unnamed_constraints_index
constraints[constraint] = {
'columns': constraint_columns,
'primary_key': False,
'unique': False,
'index': False,
'check': True,
'foreign_key': None,
}
# Now add in the indexes
cursor.execute("SHOW INDEX FROM %s" % self.connection.ops.quote_name(table_name))
for table, non_unique, index, colseq, column, order, type_ in [
x[:6] + (x[10],) for x in cursor.fetchall()
]:
if index not in constraints:
constraints[index] = {
'columns': OrderedSet(),
'primary_key': False,
'unique': not non_unique,
'check': False,
'foreign_key': None,
}
if self.connection.features.supports_index_column_ordering:
constraints[index]['orders'] = []
constraints[index]['index'] = True
constraints[index]['type'] = Index.suffix if type_ == 'BTREE' else type_.lower()
constraints[index]['columns'].add(column)
if self.connection.features.supports_index_column_ordering:
constraints[index]['orders'].append('DESC' if order == 'D' else 'ASC')
# Convert the sorted sets to lists
for constraint in constraints.values():
constraint['columns'] = list(constraint['columns'])
return constraints
|
acd2f9229e97155cd54f9ff573540e62d67f0b7c1ac9d646dd84a797534c29a7 | """
MySQL database backend for Django.
Requires mysqlclient: https://pypi.org/project/mysqlclient/
"""
from django.core.exceptions import ImproperlyConfigured
from django.db import IntegrityError
from django.db.backends import utils as backend_utils
from django.db.backends.base.base import BaseDatabaseWrapper
from django.utils.asyncio import async_unsafe
from django.utils.functional import cached_property
from django.utils.regex_helper import _lazy_re_compile
try:
import MySQLdb as Database
except ImportError as err:
raise ImproperlyConfigured(
'Error loading MySQLdb module.\n'
'Did you install mysqlclient?'
) from err
from MySQLdb.constants import CLIENT, FIELD_TYPE
from MySQLdb.converters import conversions
# Some of these import MySQLdb, so import them after checking if it's installed.
from .client import DatabaseClient
from .creation import DatabaseCreation
from .features import DatabaseFeatures
from .introspection import DatabaseIntrospection
from .operations import DatabaseOperations
from .schema import DatabaseSchemaEditor
from .validation import DatabaseValidation
version = Database.version_info
if version < (1, 4, 0):
raise ImproperlyConfigured('mysqlclient 1.4.0 or newer is required; you have %s.' % Database.__version__)
# MySQLdb returns TIME columns as timedelta -- they are more like timedelta in
# terms of actual behavior as they are signed and include days -- and Django
# expects time.
django_conversions = {
**conversions,
**{FIELD_TYPE.TIME: backend_utils.typecast_time},
}
# This should match the numerical portion of the version numbers (we can treat
# versions like 5.0.24 and 5.0.24a as the same).
server_version_re = _lazy_re_compile(r'(\d{1,2})\.(\d{1,2})\.(\d{1,2})')
class CursorWrapper:
"""
A thin wrapper around MySQLdb's normal cursor class that catches particular
exception instances and reraises them with the correct types.
Implemented as a wrapper, rather than a subclass, so that it isn't stuck
to the particular underlying representation returned by Connection.cursor().
"""
codes_for_integrityerror = (
1048, # Column cannot be null
1690, # BIGINT UNSIGNED value is out of range
3819, # CHECK constraint is violated
4025, # CHECK constraint failed
)
def __init__(self, cursor):
self.cursor = cursor
def execute(self, query, args=None):
try:
# args is None means no string interpolation
return self.cursor.execute(query, args)
except Database.OperationalError as e:
# Map some error codes to IntegrityError, since they seem to be
# misclassified and Django would prefer the more logical place.
if e.args[0] in self.codes_for_integrityerror:
raise IntegrityError(*tuple(e.args))
raise
def executemany(self, query, args):
try:
return self.cursor.executemany(query, args)
except Database.OperationalError as e:
# Map some error codes to IntegrityError, since they seem to be
# misclassified and Django would prefer the more logical place.
if e.args[0] in self.codes_for_integrityerror:
raise IntegrityError(*tuple(e.args))
raise
def __getattr__(self, attr):
return getattr(self.cursor, attr)
def __iter__(self):
return iter(self.cursor)
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'mysql'
# This dictionary maps Field objects to their associated MySQL column
# types, as strings. Column-type strings can contain format strings; they'll
# be interpolated against the values of Field.__dict__ before being output.
# If a column type is set to None, it won't be included in the output.
data_types = {
'AutoField': 'integer AUTO_INCREMENT',
'BigAutoField': 'bigint AUTO_INCREMENT',
'BinaryField': 'longblob',
'BooleanField': 'bool',
'CharField': 'varchar(%(max_length)s)',
'DateField': 'date',
'DateTimeField': 'datetime(6)',
'DecimalField': 'numeric(%(max_digits)s, %(decimal_places)s)',
'DurationField': 'bigint',
'FileField': 'varchar(%(max_length)s)',
'FilePathField': 'varchar(%(max_length)s)',
'FloatField': 'double precision',
'IntegerField': 'integer',
'BigIntegerField': 'bigint',
'IPAddressField': 'char(15)',
'GenericIPAddressField': 'char(39)',
'JSONField': 'json',
'OneToOneField': 'integer',
'PositiveBigIntegerField': 'bigint UNSIGNED',
'PositiveIntegerField': 'integer UNSIGNED',
'PositiveSmallIntegerField': 'smallint UNSIGNED',
'SlugField': 'varchar(%(max_length)s)',
'SmallAutoField': 'smallint AUTO_INCREMENT',
'SmallIntegerField': 'smallint',
'TextField': 'longtext',
'TimeField': 'time(6)',
'UUIDField': 'char(32)',
}
# For these data types:
# - MySQL < 8.0.13 doesn't accept default values and implicitly treats them
# as nullable
# - all versions of MySQL and MariaDB don't support full width database
# indexes
_limited_data_types = (
'tinyblob', 'blob', 'mediumblob', 'longblob', 'tinytext', 'text',
'mediumtext', 'longtext', 'json',
)
operators = {
'exact': '= %s',
'iexact': 'LIKE %s',
'contains': 'LIKE BINARY %s',
'icontains': 'LIKE %s',
'gt': '> %s',
'gte': '>= %s',
'lt': '< %s',
'lte': '<= %s',
'startswith': 'LIKE BINARY %s',
'endswith': 'LIKE BINARY %s',
'istartswith': 'LIKE %s',
'iendswith': 'LIKE %s',
}
# The patterns below are used to generate SQL pattern lookup clauses when
# the right-hand side of the lookup isn't a raw string (it might be an expression
# or the result of a bilateral transformation).
# In those cases, special characters for LIKE operators (e.g. \, *, _) should be
# escaped on database side.
#
# Note: we use str.format() here for readability as '%' is used as a wildcard for
# the LIKE operator.
pattern_esc = r"REPLACE(REPLACE(REPLACE({}, '\\', '\\\\'), '%%', '\%%'), '_', '\_')"
pattern_ops = {
'contains': "LIKE BINARY CONCAT('%%', {}, '%%')",
'icontains': "LIKE CONCAT('%%', {}, '%%')",
'startswith': "LIKE BINARY CONCAT({}, '%%')",
'istartswith': "LIKE CONCAT({}, '%%')",
'endswith': "LIKE BINARY CONCAT('%%', {})",
'iendswith': "LIKE CONCAT('%%', {})",
}
isolation_levels = {
'read uncommitted',
'read committed',
'repeatable read',
'serializable',
}
Database = Database
SchemaEditorClass = DatabaseSchemaEditor
# Classes instantiated in __init__().
client_class = DatabaseClient
creation_class = DatabaseCreation
features_class = DatabaseFeatures
introspection_class = DatabaseIntrospection
ops_class = DatabaseOperations
validation_class = DatabaseValidation
def get_connection_params(self):
kwargs = {
'conv': django_conversions,
'charset': 'utf8',
}
settings_dict = self.settings_dict
if settings_dict['USER']:
kwargs['user'] = settings_dict['USER']
if settings_dict['NAME']:
kwargs['database'] = settings_dict['NAME']
if settings_dict['PASSWORD']:
kwargs['password'] = settings_dict['PASSWORD']
if settings_dict['HOST'].startswith('/'):
kwargs['unix_socket'] = settings_dict['HOST']
elif settings_dict['HOST']:
kwargs['host'] = settings_dict['HOST']
if settings_dict['PORT']:
kwargs['port'] = int(settings_dict['PORT'])
# We need the number of potentially affected rows after an
# "UPDATE", not the number of changed rows.
kwargs['client_flag'] = CLIENT.FOUND_ROWS
# Validate the transaction isolation level, if specified.
options = settings_dict['OPTIONS'].copy()
isolation_level = options.pop('isolation_level', 'read committed')
if isolation_level:
isolation_level = isolation_level.lower()
if isolation_level not in self.isolation_levels:
raise ImproperlyConfigured(
"Invalid transaction isolation level '%s' specified.\n"
"Use one of %s, or None." % (
isolation_level,
', '.join("'%s'" % s for s in sorted(self.isolation_levels))
))
self.isolation_level = isolation_level
kwargs.update(options)
return kwargs
@async_unsafe
def get_new_connection(self, conn_params):
connection = Database.connect(**conn_params)
# bytes encoder in mysqlclient doesn't work and was added only to
# prevent KeyErrors in Django < 2.0. We can remove this workaround when
# mysqlclient 2.1 becomes the minimal mysqlclient supported by Django.
# See https://github.com/PyMySQL/mysqlclient/issues/489
if connection.encoders.get(bytes) is bytes:
connection.encoders.pop(bytes)
return connection
def init_connection_state(self):
assignments = []
if self.features.is_sql_auto_is_null_enabled:
# SQL_AUTO_IS_NULL controls whether an AUTO_INCREMENT column on
# a recently inserted row will return when the field is tested
# for NULL. Disabling this brings this aspect of MySQL in line
# with SQL standards.
assignments.append('SET SQL_AUTO_IS_NULL = 0')
if self.isolation_level:
assignments.append('SET SESSION TRANSACTION ISOLATION LEVEL %s' % self.isolation_level.upper())
if assignments:
with self.cursor() as cursor:
cursor.execute('; '.join(assignments))
@async_unsafe
def create_cursor(self, name=None):
cursor = self.connection.cursor()
return CursorWrapper(cursor)
def _rollback(self):
try:
BaseDatabaseWrapper._rollback(self)
except Database.NotSupportedError:
pass
def _set_autocommit(self, autocommit):
with self.wrap_database_errors:
self.connection.autocommit(autocommit)
def disable_constraint_checking(self):
"""
Disable foreign key checks, primarily for use in adding rows with
forward references. Always return True to indicate constraint checks
need to be re-enabled.
"""
with self.cursor() as cursor:
cursor.execute('SET foreign_key_checks=0')
return True
def enable_constraint_checking(self):
"""
Re-enable foreign key checks after they have been disabled.
"""
# Override needs_rollback in case constraint_checks_disabled is
# nested inside transaction.atomic.
self.needs_rollback, needs_rollback = False, self.needs_rollback
try:
with self.cursor() as cursor:
cursor.execute('SET foreign_key_checks=1')
finally:
self.needs_rollback = needs_rollback
def check_constraints(self, table_names=None):
"""
Check each table name in `table_names` for rows with invalid foreign
key references. This method is intended to be used in conjunction with
`disable_constraint_checking()` and `enable_constraint_checking()`, to
determine if rows with invalid references were entered while constraint
checks were off.
"""
with self.cursor() as cursor:
if table_names is None:
table_names = self.introspection.table_names(cursor)
for table_name in table_names:
primary_key_column_name = self.introspection.get_primary_key_column(cursor, table_name)
if not primary_key_column_name:
continue
relations = self.introspection.get_relations(cursor, table_name)
for column_name, (referenced_column_name, referenced_table_name) in relations.items():
cursor.execute(
"""
SELECT REFERRING.`%s`, REFERRING.`%s` FROM `%s` as REFERRING
LEFT JOIN `%s` as REFERRED
ON (REFERRING.`%s` = REFERRED.`%s`)
WHERE REFERRING.`%s` IS NOT NULL AND REFERRED.`%s` IS NULL
""" % (
primary_key_column_name, column_name, table_name,
referenced_table_name, column_name, referenced_column_name,
column_name, referenced_column_name,
)
)
for bad_row in cursor.fetchall():
raise IntegrityError(
"The row in table '%s' with primary key '%s' has an invalid "
"foreign key: %s.%s contains a value '%s' that does not "
"have a corresponding value in %s.%s."
% (
table_name, bad_row[0], table_name, column_name,
bad_row[1], referenced_table_name, referenced_column_name,
)
)
def is_usable(self):
try:
self.connection.ping()
except Database.Error:
return False
else:
return True
@cached_property
def display_name(self):
return 'MariaDB' if self.mysql_is_mariadb else 'MySQL'
@cached_property
def data_type_check_constraints(self):
if self.features.supports_column_check_constraints:
check_constraints = {
'PositiveBigIntegerField': '`%(column)s` >= 0',
'PositiveIntegerField': '`%(column)s` >= 0',
'PositiveSmallIntegerField': '`%(column)s` >= 0',
}
if self.mysql_is_mariadb and self.mysql_version < (10, 4, 3):
# MariaDB < 10.4.3 doesn't automatically use the JSON_VALID as
# a check constraint.
check_constraints['JSONField'] = 'JSON_VALID(`%(column)s`)'
return check_constraints
return {}
@cached_property
def mysql_server_data(self):
with self.temporary_connection() as cursor:
# Select some server variables and test if the time zone
# definitions are installed. CONVERT_TZ returns NULL if 'UTC'
# timezone isn't loaded into the mysql.time_zone table.
cursor.execute("""
SELECT VERSION(),
@@sql_mode,
@@default_storage_engine,
@@sql_auto_is_null,
@@lower_case_table_names,
CONVERT_TZ('2001-01-01 01:00:00', 'UTC', 'UTC') IS NOT NULL
""")
row = cursor.fetchone()
return {
'version': row[0],
'sql_mode': row[1],
'default_storage_engine': row[2],
'sql_auto_is_null': bool(row[3]),
'lower_case_table_names': bool(row[4]),
'has_zoneinfo_database': bool(row[5]),
}
@cached_property
def mysql_server_info(self):
return self.mysql_server_data['version']
@cached_property
def mysql_version(self):
match = server_version_re.match(self.mysql_server_info)
if not match:
raise Exception('Unable to determine MySQL version from version string %r' % self.mysql_server_info)
return tuple(int(x) for x in match.groups())
@cached_property
def mysql_is_mariadb(self):
return 'mariadb' in self.mysql_server_info.lower()
@cached_property
def sql_mode(self):
sql_mode = self.mysql_server_data['sql_mode']
return set(sql_mode.split(',') if sql_mode else ())
|
b73544cfdb59cd9d4e174a1c145faa620265f6c934751fd91f2009737c691abc | import uuid
from django.conf import settings
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.backends.utils import split_tzname_delta
from django.db.models import Exists, ExpressionWrapper, Lookup
from django.db.models.constants import OnConflict
from django.utils import timezone
from django.utils.encoding import force_str
class DatabaseOperations(BaseDatabaseOperations):
compiler_module = "django.db.backends.mysql.compiler"
# MySQL stores positive fields as UNSIGNED ints.
integer_field_ranges = {
**BaseDatabaseOperations.integer_field_ranges,
'PositiveSmallIntegerField': (0, 65535),
'PositiveIntegerField': (0, 4294967295),
'PositiveBigIntegerField': (0, 18446744073709551615),
}
cast_data_types = {
'AutoField': 'signed integer',
'BigAutoField': 'signed integer',
'SmallAutoField': 'signed integer',
'CharField': 'char(%(max_length)s)',
'DecimalField': 'decimal(%(max_digits)s, %(decimal_places)s)',
'TextField': 'char',
'IntegerField': 'signed integer',
'BigIntegerField': 'signed integer',
'SmallIntegerField': 'signed integer',
'PositiveBigIntegerField': 'unsigned integer',
'PositiveIntegerField': 'unsigned integer',
'PositiveSmallIntegerField': 'unsigned integer',
'DurationField': 'signed integer',
}
cast_char_field_without_max_length = 'char'
explain_prefix = 'EXPLAIN'
def date_extract_sql(self, lookup_type, field_name):
# https://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
if lookup_type == 'week_day':
# DAYOFWEEK() returns an integer, 1-7, Sunday=1.
return "DAYOFWEEK(%s)" % field_name
elif lookup_type == 'iso_week_day':
# WEEKDAY() returns an integer, 0-6, Monday=0.
return "WEEKDAY(%s) + 1" % field_name
elif lookup_type == 'week':
# Override the value of default_week_format for consistency with
# other database backends.
# Mode 3: Monday, 1-53, with 4 or more days this year.
return "WEEK(%s, 3)" % field_name
elif lookup_type == 'iso_year':
# Get the year part from the YEARWEEK function, which returns a
# number as year * 100 + week.
return "TRUNCATE(YEARWEEK(%s, 3), -2) / 100" % field_name
else:
# EXTRACT returns 1-53 based on ISO-8601 for the week number.
return "EXTRACT(%s FROM %s)" % (lookup_type.upper(), field_name)
def date_trunc_sql(self, lookup_type, field_name, tzname=None):
field_name = self._convert_field_to_tz(field_name, tzname)
fields = {
'year': '%%Y-01-01',
'month': '%%Y-%%m-01',
} # Use double percents to escape.
if lookup_type in fields:
format_str = fields[lookup_type]
return "CAST(DATE_FORMAT(%s, '%s') AS DATE)" % (field_name, format_str)
elif lookup_type == 'quarter':
return "MAKEDATE(YEAR(%s), 1) + INTERVAL QUARTER(%s) QUARTER - INTERVAL 1 QUARTER" % (
field_name, field_name
)
elif lookup_type == 'week':
return "DATE_SUB(%s, INTERVAL WEEKDAY(%s) DAY)" % (
field_name, field_name
)
else:
return "DATE(%s)" % (field_name)
def _prepare_tzname_delta(self, tzname):
tzname, sign, offset = split_tzname_delta(tzname)
return f'{sign}{offset}' if offset else tzname
def _convert_field_to_tz(self, field_name, tzname):
if tzname and settings.USE_TZ and self.connection.timezone_name != tzname:
field_name = "CONVERT_TZ(%s, '%s', '%s')" % (
field_name,
self.connection.timezone_name,
self._prepare_tzname_delta(tzname),
)
return field_name
def datetime_cast_date_sql(self, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return "DATE(%s)" % field_name
def datetime_cast_time_sql(self, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return "TIME(%s)" % field_name
def datetime_extract_sql(self, lookup_type, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return self.date_extract_sql(lookup_type, field_name)
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
fields = ['year', 'month', 'day', 'hour', 'minute', 'second']
format = ('%%Y-', '%%m', '-%%d', ' %%H:', '%%i', ':%%s') # Use double percents to escape.
format_def = ('0000-', '01', '-01', ' 00:', '00', ':00')
if lookup_type == 'quarter':
return (
"CAST(DATE_FORMAT(MAKEDATE(YEAR({field_name}), 1) + "
"INTERVAL QUARTER({field_name}) QUARTER - " +
"INTERVAL 1 QUARTER, '%%Y-%%m-01 00:00:00') AS DATETIME)"
).format(field_name=field_name)
if lookup_type == 'week':
return (
"CAST(DATE_FORMAT(DATE_SUB({field_name}, "
"INTERVAL WEEKDAY({field_name}) DAY), "
"'%%Y-%%m-%%d 00:00:00') AS DATETIME)"
).format(field_name=field_name)
try:
i = fields.index(lookup_type) + 1
except ValueError:
sql = field_name
else:
format_str = ''.join(format[:i] + format_def[i:])
sql = "CAST(DATE_FORMAT(%s, '%s') AS DATETIME)" % (field_name, format_str)
return sql
def time_trunc_sql(self, lookup_type, field_name, tzname=None):
field_name = self._convert_field_to_tz(field_name, tzname)
fields = {
'hour': '%%H:00:00',
'minute': '%%H:%%i:00',
'second': '%%H:%%i:%%s',
} # Use double percents to escape.
if lookup_type in fields:
format_str = fields[lookup_type]
return "CAST(DATE_FORMAT(%s, '%s') AS TIME)" % (field_name, format_str)
else:
return "TIME(%s)" % (field_name)
def fetch_returned_insert_rows(self, cursor):
"""
Given a cursor object that has just performed an INSERT...RETURNING
statement into a table, return the tuple of returned data.
"""
return cursor.fetchall()
def format_for_duration_arithmetic(self, sql):
return 'INTERVAL %s MICROSECOND' % sql
def force_no_ordering(self):
"""
"ORDER BY NULL" prevents MySQL from implicitly ordering by grouped
columns. If no ordering would otherwise be applied, we don't want any
implicit sorting going on.
"""
return [(None, ("NULL", [], False))]
def adapt_decimalfield_value(self, value, max_digits=None, decimal_places=None):
return value
def last_executed_query(self, cursor, sql, params):
# With MySQLdb, cursor objects have an (undocumented) "_executed"
# attribute where the exact query sent to the database is saved.
# See MySQLdb/cursors.py in the source distribution.
# MySQLdb returns string, PyMySQL bytes.
return force_str(getattr(cursor, '_executed', None), errors='replace')
def no_limit_value(self):
# 2**64 - 1, as recommended by the MySQL documentation
return 18446744073709551615
def quote_name(self, name):
if name.startswith("`") and name.endswith("`"):
return name # Quoting once is enough.
return "`%s`" % name
def return_insert_columns(self, fields):
# MySQL and MariaDB < 10.5.0 don't support an INSERT...RETURNING
# statement.
if not fields:
return '', ()
columns = [
'%s.%s' % (
self.quote_name(field.model._meta.db_table),
self.quote_name(field.column),
) for field in fields
]
return 'RETURNING %s' % ', '.join(columns), ()
def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):
if not tables:
return []
sql = ['SET FOREIGN_KEY_CHECKS = 0;']
if reset_sequences:
# It's faster to TRUNCATE tables that require a sequence reset
# since ALTER TABLE AUTO_INCREMENT is slower than TRUNCATE.
sql.extend(
'%s %s;' % (
style.SQL_KEYWORD('TRUNCATE'),
style.SQL_FIELD(self.quote_name(table_name)),
) for table_name in tables
)
else:
# Otherwise issue a simple DELETE since it's faster than TRUNCATE
# and preserves sequences.
sql.extend(
'%s %s %s;' % (
style.SQL_KEYWORD('DELETE'),
style.SQL_KEYWORD('FROM'),
style.SQL_FIELD(self.quote_name(table_name)),
) for table_name in tables
)
sql.append('SET FOREIGN_KEY_CHECKS = 1;')
return sql
def sequence_reset_by_name_sql(self, style, sequences):
return [
'%s %s %s %s = 1;' % (
style.SQL_KEYWORD('ALTER'),
style.SQL_KEYWORD('TABLE'),
style.SQL_FIELD(self.quote_name(sequence_info['table'])),
style.SQL_FIELD('AUTO_INCREMENT'),
) for sequence_info in sequences
]
def validate_autopk_value(self, value):
# Zero in AUTO_INCREMENT field does not work without the
# NO_AUTO_VALUE_ON_ZERO SQL mode.
if value == 0 and not self.connection.features.allows_auto_pk_0:
raise ValueError('The database backend does not accept 0 as a '
'value for AutoField.')
return value
def adapt_datetimefield_value(self, value):
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
# MySQL doesn't support tz-aware datetimes
if timezone.is_aware(value):
if settings.USE_TZ:
value = timezone.make_naive(value, self.connection.timezone)
else:
raise ValueError("MySQL backend does not support timezone-aware datetimes when USE_TZ is False.")
return str(value)
def adapt_timefield_value(self, value):
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
# MySQL doesn't support tz-aware times
if timezone.is_aware(value):
raise ValueError("MySQL backend does not support timezone-aware times.")
return value.isoformat(timespec='microseconds')
def max_name_length(self):
return 64
def pk_default_value(self):
return 'NULL'
def bulk_insert_sql(self, fields, placeholder_rows):
placeholder_rows_sql = (", ".join(row) for row in placeholder_rows)
values_sql = ", ".join("(%s)" % sql for sql in placeholder_rows_sql)
return "VALUES " + values_sql
def combine_expression(self, connector, sub_expressions):
if connector == '^':
return 'POW(%s)' % ','.join(sub_expressions)
# Convert the result to a signed integer since MySQL's binary operators
# return an unsigned integer.
elif connector in ('&', '|', '<<', '#'):
connector = '^' if connector == '#' else connector
return 'CONVERT(%s, SIGNED)' % connector.join(sub_expressions)
elif connector == '>>':
lhs, rhs = sub_expressions
return 'FLOOR(%(lhs)s / POW(2, %(rhs)s))' % {'lhs': lhs, 'rhs': rhs}
return super().combine_expression(connector, sub_expressions)
def get_db_converters(self, expression):
converters = super().get_db_converters(expression)
internal_type = expression.output_field.get_internal_type()
if internal_type == 'BooleanField':
converters.append(self.convert_booleanfield_value)
elif internal_type == 'DateTimeField':
if settings.USE_TZ:
converters.append(self.convert_datetimefield_value)
elif internal_type == 'UUIDField':
converters.append(self.convert_uuidfield_value)
return converters
def convert_booleanfield_value(self, value, expression, connection):
if value in (0, 1):
value = bool(value)
return value
def convert_datetimefield_value(self, value, expression, connection):
if value is not None:
value = timezone.make_aware(value, self.connection.timezone)
return value
def convert_uuidfield_value(self, value, expression, connection):
if value is not None:
value = uuid.UUID(value)
return value
def binary_placeholder_sql(self, value):
return '_binary %s' if value is not None and not hasattr(value, 'as_sql') else '%s'
def subtract_temporals(self, internal_type, lhs, rhs):
lhs_sql, lhs_params = lhs
rhs_sql, rhs_params = rhs
if internal_type == 'TimeField':
if self.connection.mysql_is_mariadb:
# MariaDB includes the microsecond component in TIME_TO_SEC as
# a decimal. MySQL returns an integer without microseconds.
return 'CAST((TIME_TO_SEC(%(lhs)s) - TIME_TO_SEC(%(rhs)s)) * 1000000 AS SIGNED)' % {
'lhs': lhs_sql, 'rhs': rhs_sql
}, (*lhs_params, *rhs_params)
return (
"((TIME_TO_SEC(%(lhs)s) * 1000000 + MICROSECOND(%(lhs)s)) -"
" (TIME_TO_SEC(%(rhs)s) * 1000000 + MICROSECOND(%(rhs)s)))"
) % {'lhs': lhs_sql, 'rhs': rhs_sql}, tuple(lhs_params) * 2 + tuple(rhs_params) * 2
params = (*rhs_params, *lhs_params)
return "TIMESTAMPDIFF(MICROSECOND, %s, %s)" % (rhs_sql, lhs_sql), params
def explain_query_prefix(self, format=None, **options):
# Alias MySQL's TRADITIONAL to TEXT for consistency with other backends.
if format and format.upper() == 'TEXT':
format = 'TRADITIONAL'
elif not format and 'TREE' in self.connection.features.supported_explain_formats:
# Use TREE by default (if supported) as it's more informative.
format = 'TREE'
analyze = options.pop('analyze', False)
prefix = super().explain_query_prefix(format, **options)
if analyze and self.connection.features.supports_explain_analyze:
# MariaDB uses ANALYZE instead of EXPLAIN ANALYZE.
prefix = 'ANALYZE' if self.connection.mysql_is_mariadb else prefix + ' ANALYZE'
if format and not (analyze and not self.connection.mysql_is_mariadb):
# Only MariaDB supports the analyze option with formats.
prefix += ' FORMAT=%s' % format
return prefix
def regex_lookup(self, lookup_type):
# REGEXP BINARY doesn't work correctly in MySQL 8+ and REGEXP_LIKE
# doesn't exist in MySQL 5.x or in MariaDB.
if self.connection.mysql_version < (8, 0, 0) or self.connection.mysql_is_mariadb:
if lookup_type == 'regex':
return '%s REGEXP BINARY %s'
return '%s REGEXP %s'
match_option = 'c' if lookup_type == 'regex' else 'i'
return "REGEXP_LIKE(%%s, %%s, '%s')" % match_option
def insert_statement(self, on_conflict=None):
if on_conflict == OnConflict.IGNORE:
return 'INSERT IGNORE INTO'
return super().insert_statement(on_conflict=on_conflict)
def lookup_cast(self, lookup_type, internal_type=None):
lookup = '%s'
if internal_type == 'JSONField':
if self.connection.mysql_is_mariadb or lookup_type in (
'iexact', 'contains', 'icontains', 'startswith', 'istartswith',
'endswith', 'iendswith', 'regex', 'iregex',
):
lookup = 'JSON_UNQUOTE(%s)'
return lookup
def conditional_expression_supported_in_where_clause(self, expression):
# MySQL ignores indexes with boolean fields unless they're compared
# directly to a boolean value.
if isinstance(expression, (Exists, Lookup)):
return True
if isinstance(expression, ExpressionWrapper) and expression.conditional:
return self.conditional_expression_supported_in_where_clause(expression.expression)
if getattr(expression, 'conditional', False):
return False
return super().conditional_expression_supported_in_where_clause(expression)
def on_conflict_suffix_sql(self, fields, on_conflict, update_fields, unique_fields):
if on_conflict == OnConflict.UPDATE:
conflict_suffix_sql = 'ON DUPLICATE KEY UPDATE %(fields)s'
field_sql = '%(field)s = VALUES(%(field)s)'
# The use of VALUES() is deprecated in MySQL 8.0.20+. Instead, use
# aliases for the new row and its columns available in MySQL
# 8.0.19+.
if not self.connection.mysql_is_mariadb:
if self.connection.mysql_version >= (8, 0, 19):
conflict_suffix_sql = f'AS new {conflict_suffix_sql}'
field_sql = '%(field)s = new.%(field)s'
# VALUES() was renamed to VALUE() in MariaDB 10.3.3+.
elif self.connection.mysql_version >= (10, 3, 3):
field_sql = '%(field)s = VALUE(%(field)s)'
fields = ', '.join([
field_sql % {'field': field}
for field in map(self.quote_name, update_fields)
])
return conflict_suffix_sql % {'fields': fields}
return super().on_conflict_suffix_sql(
fields, on_conflict, update_fields, unique_fields,
)
|
a299f1c5427dd6dbe1a4e9fc596aa9033d8ff97cea508b1422e7603e48845ce4 | from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.models import NOT_PROVIDED
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
sql_rename_table = "RENAME TABLE %(old_table)s TO %(new_table)s"
sql_alter_column_null = "MODIFY %(column)s %(type)s NULL"
sql_alter_column_not_null = "MODIFY %(column)s %(type)s NOT NULL"
sql_alter_column_type = "MODIFY %(column)s %(type)s"
sql_alter_column_collate = "MODIFY %(column)s %(type)s%(collation)s"
sql_alter_column_no_default_null = 'ALTER COLUMN %(column)s SET DEFAULT NULL'
# No 'CASCADE' which works as a no-op in MySQL but is undocumented
sql_delete_column = "ALTER TABLE %(table)s DROP COLUMN %(column)s"
sql_delete_unique = "ALTER TABLE %(table)s DROP INDEX %(name)s"
sql_create_column_inline_fk = (
', ADD CONSTRAINT %(name)s FOREIGN KEY (%(column)s) '
'REFERENCES %(to_table)s(%(to_column)s)'
)
sql_delete_fk = "ALTER TABLE %(table)s DROP FOREIGN KEY %(name)s"
sql_delete_index = "DROP INDEX %(name)s ON %(table)s"
sql_create_pk = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s PRIMARY KEY (%(columns)s)"
sql_delete_pk = "ALTER TABLE %(table)s DROP PRIMARY KEY"
sql_create_index = 'CREATE INDEX %(name)s ON %(table)s (%(columns)s)%(extra)s'
@property
def sql_delete_check(self):
if self.connection.mysql_is_mariadb:
# The name of the column check constraint is the same as the field
# name on MariaDB. Adding IF EXISTS clause prevents migrations
# crash. Constraint is removed during a "MODIFY" column statement.
return 'ALTER TABLE %(table)s DROP CONSTRAINT IF EXISTS %(name)s'
return 'ALTER TABLE %(table)s DROP CHECK %(name)s'
@property
def sql_rename_column(self):
# MariaDB >= 10.5.2 and MySQL >= 8.0.4 support an
# "ALTER TABLE ... RENAME COLUMN" statement.
if self.connection.mysql_is_mariadb:
if self.connection.mysql_version >= (10, 5, 2):
return super().sql_rename_column
elif self.connection.mysql_version >= (8, 0, 4):
return super().sql_rename_column
return 'ALTER TABLE %(table)s CHANGE %(old_column)s %(new_column)s %(type)s'
def quote_value(self, value):
self.connection.ensure_connection()
if isinstance(value, str):
value = value.replace('%', '%%')
# MySQLdb escapes to string, PyMySQL to bytes.
quoted = self.connection.connection.escape(value, self.connection.connection.encoders)
if isinstance(value, str) and isinstance(quoted, bytes):
quoted = quoted.decode()
return quoted
def _is_limited_data_type(self, field):
db_type = field.db_type(self.connection)
return db_type is not None and db_type.lower() in self.connection._limited_data_types
def skip_default(self, field):
if not self._supports_limited_data_type_defaults:
return self._is_limited_data_type(field)
return False
def skip_default_on_alter(self, field):
if self._is_limited_data_type(field) and not self.connection.mysql_is_mariadb:
# MySQL doesn't support defaults for BLOB and TEXT in the
# ALTER COLUMN statement.
return True
return False
@property
def _supports_limited_data_type_defaults(self):
# MariaDB and MySQL >= 8.0.13 support defaults for BLOB and TEXT.
if self.connection.mysql_is_mariadb:
return True
return self.connection.mysql_version >= (8, 0, 13)
def _column_default_sql(self, field):
if (
not self.connection.mysql_is_mariadb and
self._supports_limited_data_type_defaults and
self._is_limited_data_type(field)
):
# MySQL supports defaults for BLOB and TEXT columns only if the
# default value is written as an expression i.e. in parentheses.
return '(%s)'
return super()._column_default_sql(field)
def add_field(self, model, field):
super().add_field(model, field)
# Simulate the effect of a one-off default.
# field.default may be unhashable, so a set isn't used for "in" check.
if self.skip_default(field) and field.default not in (None, NOT_PROVIDED):
effective_default = self.effective_default(field)
self.execute('UPDATE %(table)s SET %(column)s = %%s' % {
'table': self.quote_name(model._meta.db_table),
'column': self.quote_name(field.column),
}, [effective_default])
def _field_should_be_indexed(self, model, field):
if not super()._field_should_be_indexed(model, field):
return False
storage = self.connection.introspection.get_storage_engine(
self.connection.cursor(), model._meta.db_table
)
# No need to create an index for ForeignKey fields except if
# db_constraint=False because the index from that constraint won't be
# created.
if (storage == "InnoDB" and
field.get_internal_type() == 'ForeignKey' and
field.db_constraint):
return False
return not self._is_limited_data_type(field)
def _delete_composed_index(self, model, fields, *args):
"""
MySQL can remove an implicit FK index on a field when that field is
covered by another index like a unique_together. "covered" here means
that the more complex index starts like the simpler one.
https://bugs.mysql.com/bug.php?id=37910 / Django ticket #24757
We check here before removing the [unique|index]_together if we have to
recreate a FK index.
"""
first_field = model._meta.get_field(fields[0])
if first_field.get_internal_type() == 'ForeignKey':
constraint_names = self._constraint_names(model, [first_field.column], index=True)
if not constraint_names:
self.execute(
self._create_index_sql(model, fields=[first_field], suffix='')
)
return super()._delete_composed_index(model, fields, *args)
def _set_field_new_type_null_status(self, field, new_type):
"""
Keep the null property of the old field. If it has changed, it will be
handled separately.
"""
if field.null:
new_type += " NULL"
else:
new_type += " NOT NULL"
return new_type
def _alter_column_type_sql(self, model, old_field, new_field, new_type):
new_type = self._set_field_new_type_null_status(old_field, new_type)
return super()._alter_column_type_sql(model, old_field, new_field, new_type)
def _rename_field_sql(self, table, old_field, new_field, new_type):
new_type = self._set_field_new_type_null_status(old_field, new_type)
return super()._rename_field_sql(table, old_field, new_field, new_type)
|
e676049ebd0f40626352935c4c14e9a5239d5141ad067f6a61c708ee9badff9e | """
Dummy database backend for Django.
Django uses this if the database ENGINE setting is empty (None or empty string).
Each of these API functions, except connection.close(), raise
ImproperlyConfigured.
"""
from django.core.exceptions import ImproperlyConfigured
from django.db.backends.base.base import BaseDatabaseWrapper
from django.db.backends.base.client import BaseDatabaseClient
from django.db.backends.base.creation import BaseDatabaseCreation
from django.db.backends.base.introspection import BaseDatabaseIntrospection
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.backends.dummy.features import DummyDatabaseFeatures
def complain(*args, **kwargs):
raise ImproperlyConfigured("settings.DATABASES is improperly configured. "
"Please supply the ENGINE value. Check "
"settings documentation for more details.")
def ignore(*args, **kwargs):
pass
class DatabaseOperations(BaseDatabaseOperations):
quote_name = complain
class DatabaseClient(BaseDatabaseClient):
runshell = complain
class DatabaseCreation(BaseDatabaseCreation):
create_test_db = ignore
destroy_test_db = ignore
class DatabaseIntrospection(BaseDatabaseIntrospection):
get_table_list = complain
get_table_description = complain
get_relations = complain
get_indexes = complain
class DatabaseWrapper(BaseDatabaseWrapper):
operators = {}
# Override the base class implementations with null
# implementations. Anything that tries to actually
# do something raises complain; anything that tries
# to rollback or undo something raises ignore.
_cursor = complain
ensure_connection = complain
_commit = complain
_rollback = ignore
_close = ignore
_savepoint = ignore
_savepoint_commit = complain
_savepoint_rollback = ignore
_set_autocommit = complain
# Classes instantiated in __init__().
client_class = DatabaseClient
creation_class = DatabaseCreation
features_class = DummyDatabaseFeatures
introspection_class = DatabaseIntrospection
ops_class = DatabaseOperations
def is_usable(self):
return True
|
41a5bf67f8879bec17b9699d37f829c83be0e3c03a38b3651730d521f4e80fbe | import operator
from django.db import InterfaceError
from django.db.backends.base.features import BaseDatabaseFeatures
from django.utils.functional import cached_property
class DatabaseFeatures(BaseDatabaseFeatures):
allows_group_by_selected_pks = True
can_return_columns_from_insert = True
can_return_rows_from_bulk_insert = True
has_real_datatype = True
has_native_uuid_field = True
has_native_duration_field = True
has_native_json_field = True
can_defer_constraint_checks = True
has_select_for_update = True
has_select_for_update_nowait = True
has_select_for_update_of = True
has_select_for_update_skip_locked = True
has_select_for_no_key_update = True
can_release_savepoints = True
supports_tablespaces = True
supports_transactions = True
can_introspect_materialized_views = True
can_distinct_on_fields = True
can_rollback_ddl = True
supports_combined_alters = True
nulls_order_largest = True
closed_cursor_error_class = InterfaceError
greatest_least_ignores_nulls = True
can_clone_databases = True
supports_temporal_subtraction = True
supports_slicing_ordering_in_compound = True
create_test_procedure_without_params_sql = """
CREATE FUNCTION test_procedure () RETURNS void AS $$
DECLARE
V_I INTEGER;
BEGIN
V_I := 1;
END;
$$ LANGUAGE plpgsql;"""
create_test_procedure_with_int_param_sql = """
CREATE FUNCTION test_procedure (P_I INTEGER) RETURNS void AS $$
DECLARE
V_I INTEGER;
BEGIN
V_I := P_I;
END;
$$ LANGUAGE plpgsql;"""
requires_casted_case_in_updates = True
supports_over_clause = True
only_supports_unbounded_with_preceding_and_following = True
supports_aggregate_filter_clause = True
supported_explain_formats = {'JSON', 'TEXT', 'XML', 'YAML'}
validates_explain_options = False # A query will error on invalid options.
supports_deferrable_unique_constraints = True
has_json_operators = True
json_key_contains_list_matching_requires_list = True
supports_update_conflicts = True
supports_update_conflicts_with_target = True
test_collations = {
'non_default': 'sv-x-icu',
'swedish_ci': 'sv-x-icu',
}
test_now_utc_template = "STATEMENT_TIMESTAMP() AT TIME ZONE 'UTC'"
django_test_skips = {
'opclasses are PostgreSQL only.': {
'indexes.tests.SchemaIndexesNotPostgreSQLTests.test_create_index_ignores_opclasses',
},
}
@cached_property
def introspected_field_types(self):
return {
**super().introspected_field_types,
'PositiveBigIntegerField': 'BigIntegerField',
'PositiveIntegerField': 'IntegerField',
'PositiveSmallIntegerField': 'SmallIntegerField',
}
@cached_property
def is_postgresql_11(self):
return self.connection.pg_version >= 110000
@cached_property
def is_postgresql_12(self):
return self.connection.pg_version >= 120000
@cached_property
def is_postgresql_13(self):
return self.connection.pg_version >= 130000
@cached_property
def is_postgresql_14(self):
return self.connection.pg_version >= 140000
has_bit_xor = property(operator.attrgetter('is_postgresql_14'))
has_websearch_to_tsquery = property(operator.attrgetter('is_postgresql_11'))
supports_covering_indexes = property(operator.attrgetter('is_postgresql_11'))
supports_covering_gist_indexes = property(operator.attrgetter('is_postgresql_12'))
supports_covering_spgist_indexes = property(operator.attrgetter('is_postgresql_14'))
supports_non_deterministic_collations = property(operator.attrgetter('is_postgresql_12'))
|
ce7a85c424240418585ba12b7167689ef7e2fc04d4e94eb91a941dd065884073 | from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo, TableInfo,
)
from django.db.models import Index
class DatabaseIntrospection(BaseDatabaseIntrospection):
# Maps type codes to Django Field types.
data_types_reverse = {
16: 'BooleanField',
17: 'BinaryField',
20: 'BigIntegerField',
21: 'SmallIntegerField',
23: 'IntegerField',
25: 'TextField',
700: 'FloatField',
701: 'FloatField',
869: 'GenericIPAddressField',
1042: 'CharField', # blank-padded
1043: 'CharField',
1082: 'DateField',
1083: 'TimeField',
1114: 'DateTimeField',
1184: 'DateTimeField',
1186: 'DurationField',
1266: 'TimeField',
1700: 'DecimalField',
2950: 'UUIDField',
3802: 'JSONField',
}
# A hook for subclasses.
index_default_access_method = 'btree'
ignored_tables = []
def get_field_type(self, data_type, description):
field_type = super().get_field_type(data_type, description)
if description.default and 'nextval' in description.default:
if field_type == 'IntegerField':
return 'AutoField'
elif field_type == 'BigIntegerField':
return 'BigAutoField'
elif field_type == 'SmallIntegerField':
return 'SmallAutoField'
return field_type
def get_table_list(self, cursor):
"""Return a list of table and view names in the current database."""
cursor.execute("""
SELECT c.relname,
CASE WHEN c.relispartition THEN 'p' WHEN c.relkind IN ('m', 'v') THEN 'v' ELSE 't' END
FROM pg_catalog.pg_class c
LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHERE c.relkind IN ('f', 'm', 'p', 'r', 'v')
AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
AND pg_catalog.pg_table_is_visible(c.oid)
""")
return [TableInfo(*row) for row in cursor.fetchall() if row[0] not in self.ignored_tables]
def get_table_description(self, cursor, table_name):
"""
Return a description of the table with the DB-API cursor.description
interface.
"""
# Query the pg_catalog tables as cursor.description does not reliably
# return the nullable property and information_schema.columns does not
# contain details of materialized views.
cursor.execute("""
SELECT
a.attname AS column_name,
NOT (a.attnotnull OR (t.typtype = 'd' AND t.typnotnull)) AS is_nullable,
pg_get_expr(ad.adbin, ad.adrelid) AS column_default,
CASE WHEN collname = 'default' THEN NULL ELSE collname END AS collation
FROM pg_attribute a
LEFT JOIN pg_attrdef ad ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum
LEFT JOIN pg_collation co ON a.attcollation = co.oid
JOIN pg_type t ON a.atttypid = t.oid
JOIN pg_class c ON a.attrelid = c.oid
JOIN pg_namespace n ON c.relnamespace = n.oid
WHERE c.relkind IN ('f', 'm', 'p', 'r', 'v')
AND c.relname = %s
AND n.nspname NOT IN ('pg_catalog', 'pg_toast')
AND pg_catalog.pg_table_is_visible(c.oid)
""", [table_name])
field_map = {line[0]: line[1:] for line in cursor.fetchall()}
cursor.execute("SELECT * FROM %s LIMIT 1" % self.connection.ops.quote_name(table_name))
return [
FieldInfo(
line.name,
line.type_code,
line.display_size,
line.internal_size,
line.precision,
line.scale,
*field_map[line.name],
)
for line in cursor.description
]
def get_sequences(self, cursor, table_name, table_fields=()):
cursor.execute("""
SELECT s.relname as sequence_name, col.attname
FROM pg_class s
JOIN pg_namespace sn ON sn.oid = s.relnamespace
JOIN pg_depend d ON d.refobjid = s.oid AND d.refclassid = 'pg_class'::regclass
JOIN pg_attrdef ad ON ad.oid = d.objid AND d.classid = 'pg_attrdef'::regclass
JOIN pg_attribute col ON col.attrelid = ad.adrelid AND col.attnum = ad.adnum
JOIN pg_class tbl ON tbl.oid = ad.adrelid
WHERE s.relkind = 'S'
AND d.deptype in ('a', 'n')
AND pg_catalog.pg_table_is_visible(tbl.oid)
AND tbl.relname = %s
""", [table_name])
return [
{'name': row[0], 'table': table_name, 'column': row[1]}
for row in cursor.fetchall()
]
def get_relations(self, cursor, table_name):
"""
Return a dictionary of {field_name: (field_name_other_table, other_table)}
representing all foreign keys in the given table.
"""
cursor.execute("""
SELECT a1.attname, c2.relname, a2.attname
FROM pg_constraint con
LEFT JOIN pg_class c1 ON con.conrelid = c1.oid
LEFT JOIN pg_class c2 ON con.confrelid = c2.oid
LEFT JOIN pg_attribute a1 ON c1.oid = a1.attrelid AND a1.attnum = con.conkey[1]
LEFT JOIN pg_attribute a2 ON c2.oid = a2.attrelid AND a2.attnum = con.confkey[1]
WHERE
c1.relname = %s AND
con.contype = 'f' AND
c1.relnamespace = c2.relnamespace AND
pg_catalog.pg_table_is_visible(c1.oid)
""", [table_name])
return {row[0]: (row[2], row[1]) for row in cursor.fetchall()}
def get_constraints(self, cursor, table_name):
"""
Retrieve any constraints or keys (unique, pk, fk, check, index) across
one or more columns. Also retrieve the definition of expression-based
indexes.
"""
constraints = {}
# Loop over the key table, collecting things as constraints. The column
# array must return column names in the same order in which they were
# created.
cursor.execute("""
SELECT
c.conname,
array(
SELECT attname
FROM unnest(c.conkey) WITH ORDINALITY cols(colid, arridx)
JOIN pg_attribute AS ca ON cols.colid = ca.attnum
WHERE ca.attrelid = c.conrelid
ORDER BY cols.arridx
),
c.contype,
(SELECT fkc.relname || '.' || fka.attname
FROM pg_attribute AS fka
JOIN pg_class AS fkc ON fka.attrelid = fkc.oid
WHERE fka.attrelid = c.confrelid AND fka.attnum = c.confkey[1]),
cl.reloptions
FROM pg_constraint AS c
JOIN pg_class AS cl ON c.conrelid = cl.oid
WHERE cl.relname = %s AND pg_catalog.pg_table_is_visible(cl.oid)
""", [table_name])
for constraint, columns, kind, used_cols, options in cursor.fetchall():
constraints[constraint] = {
"columns": columns,
"primary_key": kind == "p",
"unique": kind in ["p", "u"],
"foreign_key": tuple(used_cols.split(".", 1)) if kind == "f" else None,
"check": kind == "c",
"index": False,
"definition": None,
"options": options,
}
# Now get indexes
cursor.execute("""
SELECT
indexname, array_agg(attname ORDER BY arridx), indisunique, indisprimary,
array_agg(ordering ORDER BY arridx), amname, exprdef, s2.attoptions
FROM (
SELECT
c2.relname as indexname, idx.*, attr.attname, am.amname,
CASE
WHEN idx.indexprs IS NOT NULL THEN
pg_get_indexdef(idx.indexrelid)
END AS exprdef,
CASE am.amname
WHEN %s THEN
CASE (option & 1)
WHEN 1 THEN 'DESC' ELSE 'ASC'
END
END as ordering,
c2.reloptions as attoptions
FROM (
SELECT *
FROM pg_index i, unnest(i.indkey, i.indoption) WITH ORDINALITY koi(key, option, arridx)
) idx
LEFT JOIN pg_class c ON idx.indrelid = c.oid
LEFT JOIN pg_class c2 ON idx.indexrelid = c2.oid
LEFT JOIN pg_am am ON c2.relam = am.oid
LEFT JOIN pg_attribute attr ON attr.attrelid = c.oid AND attr.attnum = idx.key
WHERE c.relname = %s AND pg_catalog.pg_table_is_visible(c.oid)
) s2
GROUP BY indexname, indisunique, indisprimary, amname, exprdef, attoptions;
""", [self.index_default_access_method, table_name])
for index, columns, unique, primary, orders, type_, definition, options in cursor.fetchall():
if index not in constraints:
basic_index = (
type_ == self.index_default_access_method and
# '_btree' references
# django.contrib.postgres.indexes.BTreeIndex.suffix.
not index.endswith('_btree') and options is None
)
constraints[index] = {
"columns": columns if columns != [None] else [],
"orders": orders if orders != [None] else [],
"primary_key": primary,
"unique": unique,
"foreign_key": None,
"check": False,
"index": True,
"type": Index.suffix if basic_index else type_,
"definition": definition,
"options": options,
}
return constraints
|
4df0d9ffb05af91678b66bcf8d1edb592b72669ab0b4d1005068158f367b9f48 | """
PostgreSQL database backend for Django.
Requires psycopg 2: https://www.psycopg.org/
"""
import asyncio
import threading
import warnings
from contextlib import contextmanager
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import DatabaseError as WrappedDatabaseError, connections
from django.db.backends.base.base import BaseDatabaseWrapper
from django.db.backends.utils import (
CursorDebugWrapper as BaseCursorDebugWrapper,
)
from django.utils.asyncio import async_unsafe
from django.utils.functional import cached_property
from django.utils.safestring import SafeString
from django.utils.version import get_version_tuple
try:
import psycopg2 as Database
import psycopg2.extensions
import psycopg2.extras
except ImportError as e:
raise ImproperlyConfigured("Error loading psycopg2 module: %s" % e)
def psycopg2_version():
version = psycopg2.__version__.split(' ', 1)[0]
return get_version_tuple(version)
PSYCOPG2_VERSION = psycopg2_version()
if PSYCOPG2_VERSION < (2, 8, 4):
raise ImproperlyConfigured("psycopg2 version 2.8.4 or newer is required; you have %s" % psycopg2.__version__)
# Some of these import psycopg2, so import them after checking if it's installed.
from .client import DatabaseClient # NOQA
from .creation import DatabaseCreation # NOQA
from .features import DatabaseFeatures # NOQA
from .introspection import DatabaseIntrospection # NOQA
from .operations import DatabaseOperations # NOQA
from .schema import DatabaseSchemaEditor # NOQA
psycopg2.extensions.register_adapter(SafeString, psycopg2.extensions.QuotedString)
psycopg2.extras.register_uuid()
# Register support for inet[] manually so we don't have to handle the Inet()
# object on load all the time.
INETARRAY_OID = 1041
INETARRAY = psycopg2.extensions.new_array_type(
(INETARRAY_OID,),
'INETARRAY',
psycopg2.extensions.UNICODE,
)
psycopg2.extensions.register_type(INETARRAY)
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'postgresql'
display_name = 'PostgreSQL'
# This dictionary maps Field objects to their associated PostgreSQL column
# types, as strings. Column-type strings can contain format strings; they'll
# be interpolated against the values of Field.__dict__ before being output.
# If a column type is set to None, it won't be included in the output.
data_types = {
'AutoField': 'serial',
'BigAutoField': 'bigserial',
'BinaryField': 'bytea',
'BooleanField': 'boolean',
'CharField': 'varchar(%(max_length)s)',
'DateField': 'date',
'DateTimeField': 'timestamp with time zone',
'DecimalField': 'numeric(%(max_digits)s, %(decimal_places)s)',
'DurationField': 'interval',
'FileField': 'varchar(%(max_length)s)',
'FilePathField': 'varchar(%(max_length)s)',
'FloatField': 'double precision',
'IntegerField': 'integer',
'BigIntegerField': 'bigint',
'IPAddressField': 'inet',
'GenericIPAddressField': 'inet',
'JSONField': 'jsonb',
'OneToOneField': 'integer',
'PositiveBigIntegerField': 'bigint',
'PositiveIntegerField': 'integer',
'PositiveSmallIntegerField': 'smallint',
'SlugField': 'varchar(%(max_length)s)',
'SmallAutoField': 'smallserial',
'SmallIntegerField': 'smallint',
'TextField': 'text',
'TimeField': 'time',
'UUIDField': 'uuid',
}
data_type_check_constraints = {
'PositiveBigIntegerField': '"%(column)s" >= 0',
'PositiveIntegerField': '"%(column)s" >= 0',
'PositiveSmallIntegerField': '"%(column)s" >= 0',
}
operators = {
'exact': '= %s',
'iexact': '= UPPER(%s)',
'contains': 'LIKE %s',
'icontains': 'LIKE UPPER(%s)',
'regex': '~ %s',
'iregex': '~* %s',
'gt': '> %s',
'gte': '>= %s',
'lt': '< %s',
'lte': '<= %s',
'startswith': 'LIKE %s',
'endswith': 'LIKE %s',
'istartswith': 'LIKE UPPER(%s)',
'iendswith': 'LIKE UPPER(%s)',
}
# The patterns below are used to generate SQL pattern lookup clauses when
# the right-hand side of the lookup isn't a raw string (it might be an expression
# or the result of a bilateral transformation).
# In those cases, special characters for LIKE operators (e.g. \, *, _) should be
# escaped on database side.
#
# Note: we use str.format() here for readability as '%' is used as a wildcard for
# the LIKE operator.
pattern_esc = r"REPLACE(REPLACE(REPLACE({}, E'\\', E'\\\\'), E'%%', E'\\%%'), E'_', E'\\_')"
pattern_ops = {
'contains': "LIKE '%%' || {} || '%%'",
'icontains': "LIKE '%%' || UPPER({}) || '%%'",
'startswith': "LIKE {} || '%%'",
'istartswith': "LIKE UPPER({}) || '%%'",
'endswith': "LIKE '%%' || {}",
'iendswith': "LIKE '%%' || UPPER({})",
}
Database = Database
SchemaEditorClass = DatabaseSchemaEditor
# Classes instantiated in __init__().
client_class = DatabaseClient
creation_class = DatabaseCreation
features_class = DatabaseFeatures
introspection_class = DatabaseIntrospection
ops_class = DatabaseOperations
# PostgreSQL backend-specific attributes.
_named_cursor_idx = 0
def get_connection_params(self):
settings_dict = self.settings_dict
# None may be used to connect to the default 'postgres' db
if (
settings_dict['NAME'] == '' and
not settings_dict.get('OPTIONS', {}).get('service')
):
raise ImproperlyConfigured(
"settings.DATABASES is improperly configured. "
"Please supply the NAME or OPTIONS['service'] value."
)
if len(settings_dict['NAME'] or '') > self.ops.max_name_length():
raise ImproperlyConfigured(
"The database name '%s' (%d characters) is longer than "
"PostgreSQL's limit of %d characters. Supply a shorter NAME "
"in settings.DATABASES." % (
settings_dict['NAME'],
len(settings_dict['NAME']),
self.ops.max_name_length(),
)
)
conn_params = {}
if settings_dict['NAME']:
conn_params = {
'database': settings_dict['NAME'],
**settings_dict['OPTIONS'],
}
elif settings_dict['NAME'] is None:
# Connect to the default 'postgres' db.
settings_dict.get('OPTIONS', {}).pop('service', None)
conn_params = {'database': 'postgres', **settings_dict['OPTIONS']}
else:
conn_params = {**settings_dict['OPTIONS']}
conn_params.pop('isolation_level', None)
if settings_dict['USER']:
conn_params['user'] = settings_dict['USER']
if settings_dict['PASSWORD']:
conn_params['password'] = settings_dict['PASSWORD']
if settings_dict['HOST']:
conn_params['host'] = settings_dict['HOST']
if settings_dict['PORT']:
conn_params['port'] = settings_dict['PORT']
return conn_params
@async_unsafe
def get_new_connection(self, conn_params):
connection = Database.connect(**conn_params)
# self.isolation_level must be set:
# - after connecting to the database in order to obtain the database's
# default when no value is explicitly specified in options.
# - before calling _set_autocommit() because if autocommit is on, that
# will set connection.isolation_level to ISOLATION_LEVEL_AUTOCOMMIT.
options = self.settings_dict['OPTIONS']
try:
self.isolation_level = options['isolation_level']
except KeyError:
self.isolation_level = connection.isolation_level
else:
# Set the isolation level to the value from OPTIONS.
if self.isolation_level != connection.isolation_level:
connection.set_session(isolation_level=self.isolation_level)
# Register dummy loads() to avoid a round trip from psycopg2's decode
# to json.dumps() to json.loads(), when using a custom decoder in
# JSONField.
psycopg2.extras.register_default_jsonb(conn_or_curs=connection, loads=lambda x: x)
return connection
def ensure_timezone(self):
if self.connection is None:
return False
conn_timezone_name = self.connection.get_parameter_status('TimeZone')
timezone_name = self.timezone_name
if timezone_name and conn_timezone_name != timezone_name:
with self.connection.cursor() as cursor:
cursor.execute(self.ops.set_time_zone_sql(), [timezone_name])
return True
return False
def init_connection_state(self):
self.connection.set_client_encoding('UTF8')
timezone_changed = self.ensure_timezone()
if timezone_changed:
# Commit after setting the time zone (see #17062)
if not self.get_autocommit():
self.connection.commit()
@async_unsafe
def create_cursor(self, name=None):
if name:
# In autocommit mode, the cursor will be used outside of a
# transaction, hence use a holdable cursor.
cursor = self.connection.cursor(name, scrollable=False, withhold=self.connection.autocommit)
else:
cursor = self.connection.cursor()
cursor.tzinfo_factory = self.tzinfo_factory if settings.USE_TZ else None
return cursor
def tzinfo_factory(self, offset):
return self.timezone
@async_unsafe
def chunked_cursor(self):
self._named_cursor_idx += 1
# Get the current async task
# Note that right now this is behind @async_unsafe, so this is
# unreachable, but in future we'll start loosening this restriction.
# For now, it's here so that every use of "threading" is
# also async-compatible.
try:
current_task = asyncio.current_task()
except RuntimeError:
current_task = None
# Current task can be none even if the current_task call didn't error
if current_task:
task_ident = str(id(current_task))
else:
task_ident = 'sync'
# Use that and the thread ident to get a unique name
return self._cursor(
name='_django_curs_%d_%s_%d' % (
# Avoid reusing name in other threads / tasks
threading.current_thread().ident,
task_ident,
self._named_cursor_idx,
)
)
def _set_autocommit(self, autocommit):
with self.wrap_database_errors:
self.connection.autocommit = autocommit
def check_constraints(self, table_names=None):
"""
Check constraints by setting them to immediate. Return them to deferred
afterward.
"""
with self.cursor() as cursor:
cursor.execute('SET CONSTRAINTS ALL IMMEDIATE')
cursor.execute('SET CONSTRAINTS ALL DEFERRED')
def is_usable(self):
try:
# Use a psycopg cursor directly, bypassing Django's utilities.
with self.connection.cursor() as cursor:
cursor.execute('SELECT 1')
except Database.Error:
return False
else:
return True
@contextmanager
def _nodb_cursor(self):
cursor = None
try:
with super()._nodb_cursor() as cursor:
yield cursor
except (Database.DatabaseError, WrappedDatabaseError):
if cursor is not None:
raise
warnings.warn(
"Normally Django will use a connection to the 'postgres' database "
"to avoid running initialization queries against the production "
"database when it's not needed (for example, when running tests). "
"Django was unable to create a connection to the 'postgres' database "
"and will use the first PostgreSQL database instead.",
RuntimeWarning
)
for connection in connections.all():
if connection.vendor == 'postgresql' and connection.settings_dict['NAME'] != 'postgres':
conn = self.__class__(
{**self.settings_dict, 'NAME': connection.settings_dict['NAME']},
alias=self.alias,
)
try:
with conn.cursor() as cursor:
yield cursor
finally:
conn.close()
break
else:
raise
@cached_property
def pg_version(self):
with self.temporary_connection():
return self.connection.server_version
def make_debug_cursor(self, cursor):
return CursorDebugWrapper(cursor, self)
class CursorDebugWrapper(BaseCursorDebugWrapper):
def copy_expert(self, sql, file, *args):
with self.debug_sql(sql):
return self.cursor.copy_expert(sql, file, *args)
def copy_to(self, file, table, *args, **kwargs):
with self.debug_sql(sql='COPY %s TO STDOUT' % table):
return self.cursor.copy_to(file, table, *args, **kwargs)
|
e8e8a0b3339a7b20ac49cf29f07b0c276261f6517b52da7e9981045865dfe014 | from psycopg2.extras import Inet
from django.conf import settings
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.backends.utils import split_tzname_delta
from django.db.models.constants import OnConflict
class DatabaseOperations(BaseDatabaseOperations):
cast_char_field_without_max_length = 'varchar'
explain_prefix = 'EXPLAIN'
cast_data_types = {
'AutoField': 'integer',
'BigAutoField': 'bigint',
'SmallAutoField': 'smallint',
}
def unification_cast_sql(self, output_field):
internal_type = output_field.get_internal_type()
if internal_type in ("GenericIPAddressField", "IPAddressField", "TimeField", "UUIDField"):
# PostgreSQL will resolve a union as type 'text' if input types are
# 'unknown'.
# https://www.postgresql.org/docs/current/typeconv-union-case.html
# These fields cannot be implicitly cast back in the default
# PostgreSQL configuration so we need to explicitly cast them.
# We must also remove components of the type within brackets:
# varchar(255) -> varchar.
return 'CAST(%%s AS %s)' % output_field.db_type(self.connection).split('(')[0]
return '%s'
def date_extract_sql(self, lookup_type, field_name):
# https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT
if lookup_type == 'week_day':
# For consistency across backends, we return Sunday=1, Saturday=7.
return "EXTRACT('dow' FROM %s) + 1" % field_name
elif lookup_type == 'iso_week_day':
return "EXTRACT('isodow' FROM %s)" % field_name
elif lookup_type == 'iso_year':
return "EXTRACT('isoyear' FROM %s)" % field_name
else:
return "EXTRACT('%s' FROM %s)" % (lookup_type, field_name)
def date_trunc_sql(self, lookup_type, field_name, tzname=None):
field_name = self._convert_field_to_tz(field_name, tzname)
# https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC
return "DATE_TRUNC('%s', %s)" % (lookup_type, field_name)
def _prepare_tzname_delta(self, tzname):
tzname, sign, offset = split_tzname_delta(tzname)
if offset:
sign = '-' if sign == '+' else '+'
return f'{tzname}{sign}{offset}'
return tzname
def _convert_field_to_tz(self, field_name, tzname):
if tzname and settings.USE_TZ:
field_name = "%s AT TIME ZONE '%s'" % (field_name, self._prepare_tzname_delta(tzname))
return field_name
def datetime_cast_date_sql(self, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return '(%s)::date' % field_name
def datetime_cast_time_sql(self, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return '(%s)::time' % field_name
def datetime_extract_sql(self, lookup_type, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
return self.date_extract_sql(lookup_type, field_name)
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
field_name = self._convert_field_to_tz(field_name, tzname)
# https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC
return "DATE_TRUNC('%s', %s)" % (lookup_type, field_name)
def time_trunc_sql(self, lookup_type, field_name, tzname=None):
field_name = self._convert_field_to_tz(field_name, tzname)
return "DATE_TRUNC('%s', %s)::time" % (lookup_type, field_name)
def deferrable_sql(self):
return " DEFERRABLE INITIALLY DEFERRED"
def fetch_returned_insert_rows(self, cursor):
"""
Given a cursor object that has just performed an INSERT...RETURNING
statement into a table, return the tuple of returned data.
"""
return cursor.fetchall()
def lookup_cast(self, lookup_type, internal_type=None):
lookup = '%s'
# Cast text lookups to text to allow things like filter(x__contains=4)
if lookup_type in ('iexact', 'contains', 'icontains', 'startswith',
'istartswith', 'endswith', 'iendswith', 'regex', 'iregex'):
if internal_type in ('IPAddressField', 'GenericIPAddressField'):
lookup = "HOST(%s)"
elif internal_type in ('CICharField', 'CIEmailField', 'CITextField'):
lookup = '%s::citext'
else:
lookup = "%s::text"
# Use UPPER(x) for case-insensitive lookups; it's faster.
if lookup_type in ('iexact', 'icontains', 'istartswith', 'iendswith'):
lookup = 'UPPER(%s)' % lookup
return lookup
def no_limit_value(self):
return None
def prepare_sql_script(self, sql):
return [sql]
def quote_name(self, name):
if name.startswith('"') and name.endswith('"'):
return name # Quoting once is enough.
return '"%s"' % name
def set_time_zone_sql(self):
return "SET TIME ZONE %s"
def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):
if not tables:
return []
# Perform a single SQL 'TRUNCATE x, y, z...;' statement. It allows us
# to truncate tables referenced by a foreign key in any other table.
sql_parts = [
style.SQL_KEYWORD('TRUNCATE'),
', '.join(style.SQL_FIELD(self.quote_name(table)) for table in tables),
]
if reset_sequences:
sql_parts.append(style.SQL_KEYWORD('RESTART IDENTITY'))
if allow_cascade:
sql_parts.append(style.SQL_KEYWORD('CASCADE'))
return ['%s;' % ' '.join(sql_parts)]
def sequence_reset_by_name_sql(self, style, sequences):
# 'ALTER SEQUENCE sequence_name RESTART WITH 1;'... style SQL statements
# to reset sequence indices
sql = []
for sequence_info in sequences:
table_name = sequence_info['table']
# 'id' will be the case if it's an m2m using an autogenerated
# intermediate table (see BaseDatabaseIntrospection.sequence_list).
column_name = sequence_info['column'] or 'id'
sql.append("%s setval(pg_get_serial_sequence('%s','%s'), 1, false);" % (
style.SQL_KEYWORD('SELECT'),
style.SQL_TABLE(self.quote_name(table_name)),
style.SQL_FIELD(column_name),
))
return sql
def tablespace_sql(self, tablespace, inline=False):
if inline:
return "USING INDEX TABLESPACE %s" % self.quote_name(tablespace)
else:
return "TABLESPACE %s" % self.quote_name(tablespace)
def sequence_reset_sql(self, style, model_list):
from django.db import models
output = []
qn = self.quote_name
for model in model_list:
# Use `coalesce` to set the sequence for each model to the max pk value if there are records,
# or 1 if there are none. Set the `is_called` property (the third argument to `setval`) to true
# if there are records (as the max pk value is already in use), otherwise set it to false.
# Use pg_get_serial_sequence to get the underlying sequence name from the table name
# and column name (available since PostgreSQL 8)
for f in model._meta.local_fields:
if isinstance(f, models.AutoField):
output.append(
"%s setval(pg_get_serial_sequence('%s','%s'), "
"coalesce(max(%s), 1), max(%s) %s null) %s %s;" % (
style.SQL_KEYWORD('SELECT'),
style.SQL_TABLE(qn(model._meta.db_table)),
style.SQL_FIELD(f.column),
style.SQL_FIELD(qn(f.column)),
style.SQL_FIELD(qn(f.column)),
style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(qn(model._meta.db_table)),
)
)
break # Only one AutoField is allowed per model, so don't bother continuing.
return output
def prep_for_iexact_query(self, x):
return x
def max_name_length(self):
"""
Return the maximum length of an identifier.
The maximum length of an identifier is 63 by default, but can be
changed by recompiling PostgreSQL after editing the NAMEDATALEN
macro in src/include/pg_config_manual.h.
This implementation returns 63, but can be overridden by a custom
database backend that inherits most of its behavior from this one.
"""
return 63
def distinct_sql(self, fields, params):
if fields:
params = [param for param_list in params for param in param_list]
return (['DISTINCT ON (%s)' % ', '.join(fields)], params)
else:
return ['DISTINCT'], []
def last_executed_query(self, cursor, sql, params):
# https://www.psycopg.org/docs/cursor.html#cursor.query
# The query attribute is a Psycopg extension to the DB API 2.0.
if cursor.query is not None:
return cursor.query.decode()
return None
def return_insert_columns(self, fields):
if not fields:
return '', ()
columns = [
'%s.%s' % (
self.quote_name(field.model._meta.db_table),
self.quote_name(field.column),
) for field in fields
]
return 'RETURNING %s' % ', '.join(columns), ()
def bulk_insert_sql(self, fields, placeholder_rows):
placeholder_rows_sql = (", ".join(row) for row in placeholder_rows)
values_sql = ", ".join("(%s)" % sql for sql in placeholder_rows_sql)
return "VALUES " + values_sql
def adapt_datefield_value(self, value):
return value
def adapt_datetimefield_value(self, value):
return value
def adapt_timefield_value(self, value):
return value
def adapt_decimalfield_value(self, value, max_digits=None, decimal_places=None):
return value
def adapt_ipaddressfield_value(self, value):
if value:
return Inet(value)
return None
def subtract_temporals(self, internal_type, lhs, rhs):
if internal_type == 'DateField':
lhs_sql, lhs_params = lhs
rhs_sql, rhs_params = rhs
params = (*lhs_params, *rhs_params)
return "(interval '1 day' * (%s - %s))" % (lhs_sql, rhs_sql), params
return super().subtract_temporals(internal_type, lhs, rhs)
def explain_query_prefix(self, format=None, **options):
prefix = super().explain_query_prefix(format)
extra = {}
if format:
extra['FORMAT'] = format
if options:
extra.update({
name.upper(): 'true' if value else 'false'
for name, value in options.items()
})
if extra:
prefix += ' (%s)' % ', '.join('%s %s' % i for i in extra.items())
return prefix
def on_conflict_suffix_sql(self, fields, on_conflict, update_fields, unique_fields):
if on_conflict == OnConflict.IGNORE:
return 'ON CONFLICT DO NOTHING'
if on_conflict == OnConflict.UPDATE:
return 'ON CONFLICT(%s) DO UPDATE SET %s' % (
', '.join(map(self.quote_name, unique_fields)),
', '.join([
f'{field} = EXCLUDED.{field}'
for field in map(self.quote_name, update_fields)
]),
)
return super().on_conflict_suffix_sql(
fields, on_conflict, update_fields, unique_fields,
)
|
a11dbdb959e6b5eaab88ed3949749cdb2c310fef8f3e726b933c82363eea2c5f | import operator
from django.db import transaction
from django.db.backends.base.features import BaseDatabaseFeatures
from django.db.utils import OperationalError
from django.utils.functional import cached_property
from .base import Database
class DatabaseFeatures(BaseDatabaseFeatures):
test_db_allows_multiple_connections = False
supports_unspecified_pk = True
supports_timezones = False
max_query_params = 999
supports_transactions = True
atomic_transactions = False
can_rollback_ddl = True
can_create_inline_fk = False
supports_paramstyle_pyformat = False
requires_literal_defaults = True
can_clone_databases = True
supports_temporal_subtraction = True
ignores_table_name_case = True
supports_cast_with_precision = False
time_cast_precision = 3
can_release_savepoints = True
has_case_insensitive_like = True
# Is "ALTER TABLE ... RENAME COLUMN" supported?
can_alter_table_rename_column = Database.sqlite_version_info >= (3, 25, 0)
supports_parentheses_in_compound = False
# Deferred constraint checks can be emulated on SQLite < 3.20 but not in a
# reasonably performant way.
supports_pragma_foreign_key_check = Database.sqlite_version_info >= (3, 20, 0)
can_defer_constraint_checks = supports_pragma_foreign_key_check
supports_functions_in_partial_indexes = Database.sqlite_version_info >= (3, 15, 0)
supports_over_clause = Database.sqlite_version_info >= (3, 25, 0)
supports_frame_range_fixed_distance = Database.sqlite_version_info >= (3, 28, 0)
supports_aggregate_filter_clause = Database.sqlite_version_info >= (3, 30, 1)
supports_order_by_nulls_modifier = Database.sqlite_version_info >= (3, 30, 0)
order_by_nulls_first = True
supports_json_field_contains = False
supports_update_conflicts = Database.sqlite_version_info >= (3, 24, 0)
supports_update_conflicts_with_target = supports_update_conflicts
test_collations = {
'ci': 'nocase',
'cs': 'binary',
'non_default': 'nocase',
}
django_test_expected_failures = {
# The django_format_dtdelta() function doesn't properly handle mixed
# Date/DateTime fields and timedeltas.
'expressions.tests.FTimeDeltaTests.test_mixed_comparisons1',
}
@cached_property
def django_test_skips(self):
skips = {
'SQLite stores values rounded to 15 significant digits.': {
'model_fields.test_decimalfield.DecimalFieldTests.test_fetch_from_db_without_float_rounding',
},
'SQLite naively remakes the table on field alteration.': {
'schema.tests.SchemaTests.test_unique_no_unnecessary_fk_drops',
'schema.tests.SchemaTests.test_unique_and_reverse_m2m',
'schema.tests.SchemaTests.test_alter_field_default_doesnt_perform_queries',
'schema.tests.SchemaTests.test_rename_column_renames_deferred_sql_references',
},
"SQLite doesn't support negative precision for ROUND().": {
'db_functions.math.test_round.RoundTests.test_null_with_negative_precision',
'db_functions.math.test_round.RoundTests.test_decimal_with_negative_precision',
'db_functions.math.test_round.RoundTests.test_float_with_negative_precision',
'db_functions.math.test_round.RoundTests.test_integer_with_negative_precision',
},
}
if Database.sqlite_version_info < (3, 27):
skips.update({
'Nondeterministic failure on SQLite < 3.27.': {
'expressions_window.tests.WindowFunctionTests.test_subquery_row_range_rank',
},
})
if self.connection.is_in_memory_db():
skips.update({
"the sqlite backend's close() method is a no-op when using an "
"in-memory database": {
'servers.test_liveserverthread.LiveServerThreadTest.test_closes_connections',
'servers.tests.LiveServerTestCloseConnectionTest.test_closes_connections',
},
})
return skips
@cached_property
def supports_atomic_references_rename(self):
return Database.sqlite_version_info >= (3, 26, 0)
@cached_property
def introspected_field_types(self):
return{
**super().introspected_field_types,
'BigAutoField': 'AutoField',
'DurationField': 'BigIntegerField',
'GenericIPAddressField': 'CharField',
'SmallAutoField': 'AutoField',
}
@cached_property
def supports_json_field(self):
with self.connection.cursor() as cursor:
try:
with transaction.atomic(self.connection.alias):
cursor.execute('SELECT JSON(\'{"a": "b"}\')')
except OperationalError:
return False
return True
can_introspect_json_field = property(operator.attrgetter('supports_json_field'))
has_json_object_function = property(operator.attrgetter('supports_json_field'))
@cached_property
def can_return_columns_from_insert(self):
return Database.sqlite_version_info >= (3, 35)
can_return_rows_from_bulk_insert = property(operator.attrgetter('can_return_columns_from_insert'))
|
0445a97c256d575ca80de7548937e1a2231886aa6cfc55c0c770a4016e897de2 | from collections import namedtuple
import sqlparse
from django.db import DatabaseError
from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo as BaseFieldInfo, TableInfo,
)
from django.db.models import Index
from django.utils.regex_helper import _lazy_re_compile
FieldInfo = namedtuple('FieldInfo', BaseFieldInfo._fields + ('pk', 'has_json_constraint'))
field_size_re = _lazy_re_compile(r'^\s*(?:var)?char\s*\(\s*(\d+)\s*\)\s*$')
def get_field_size(name):
""" Extract the size number from a "varchar(11)" type name """
m = field_size_re.search(name)
return int(m[1]) if m else None
# This light wrapper "fakes" a dictionary interface, because some SQLite data
# types include variables in them -- e.g. "varchar(30)" -- and can't be matched
# as a simple dictionary lookup.
class FlexibleFieldLookupDict:
# Maps SQL types to Django Field types. Some of the SQL types have multiple
# entries here because SQLite allows for anything and doesn't normalize the
# field type; it uses whatever was given.
base_data_types_reverse = {
'bool': 'BooleanField',
'boolean': 'BooleanField',
'smallint': 'SmallIntegerField',
'smallint unsigned': 'PositiveSmallIntegerField',
'smallinteger': 'SmallIntegerField',
'int': 'IntegerField',
'integer': 'IntegerField',
'bigint': 'BigIntegerField',
'integer unsigned': 'PositiveIntegerField',
'bigint unsigned': 'PositiveBigIntegerField',
'decimal': 'DecimalField',
'real': 'FloatField',
'text': 'TextField',
'char': 'CharField',
'varchar': 'CharField',
'blob': 'BinaryField',
'date': 'DateField',
'datetime': 'DateTimeField',
'time': 'TimeField',
}
def __getitem__(self, key):
key = key.lower().split('(', 1)[0].strip()
return self.base_data_types_reverse[key]
class DatabaseIntrospection(BaseDatabaseIntrospection):
data_types_reverse = FlexibleFieldLookupDict()
def get_field_type(self, data_type, description):
field_type = super().get_field_type(data_type, description)
if description.pk and field_type in {'BigIntegerField', 'IntegerField', 'SmallIntegerField'}:
# No support for BigAutoField or SmallAutoField as SQLite treats
# all integer primary keys as signed 64-bit integers.
return 'AutoField'
if description.has_json_constraint:
return 'JSONField'
return field_type
def get_table_list(self, cursor):
"""Return a list of table and view names in the current database."""
# Skip the sqlite_sequence system table used for autoincrement key
# generation.
cursor.execute("""
SELECT name, type FROM sqlite_master
WHERE type in ('table', 'view') AND NOT name='sqlite_sequence'
ORDER BY name""")
return [TableInfo(row[0], row[1][0]) for row in cursor.fetchall()]
def get_table_description(self, cursor, table_name):
"""
Return a description of the table with the DB-API cursor.description
interface.
"""
cursor.execute('PRAGMA table_info(%s)' % self.connection.ops.quote_name(table_name))
table_info = cursor.fetchall()
if not table_info:
raise DatabaseError(f'Table {table_name} does not exist (empty pragma).')
collations = self._get_column_collations(cursor, table_name)
json_columns = set()
if self.connection.features.can_introspect_json_field:
for line in table_info:
column = line[1]
json_constraint_sql = '%%json_valid("%s")%%' % column
has_json_constraint = cursor.execute("""
SELECT sql
FROM sqlite_master
WHERE
type = 'table' AND
name = %s AND
sql LIKE %s
""", [table_name, json_constraint_sql]).fetchone()
if has_json_constraint:
json_columns.add(column)
return [
FieldInfo(
name, data_type, None, get_field_size(data_type), None, None,
not notnull, default, collations.get(name), pk == 1, name in json_columns
)
for cid, name, data_type, notnull, default, pk in table_info
]
def get_sequences(self, cursor, table_name, table_fields=()):
pk_col = self.get_primary_key_column(cursor, table_name)
return [{'table': table_name, 'column': pk_col}]
def get_relations(self, cursor, table_name):
"""
Return a dictionary of {column_name: (ref_column_name, ref_table_name)}
representing all foreign keys in the given table.
"""
cursor.execute(
'PRAGMA foreign_key_list(%s)' % self.connection.ops.quote_name(table_name)
)
return {
column_name: (ref_column_name, ref_table_name)
for _, _, ref_table_name, column_name, ref_column_name, *_ in cursor.fetchall()
}
def get_primary_key_column(self, cursor, table_name):
"""Return the column name of the primary key for the given table."""
cursor.execute(
'PRAGMA table_info(%s)' % self.connection.ops.quote_name(table_name)
)
for _, name, *_, pk in cursor.fetchall():
if pk:
return name
return None
def _parse_column_or_constraint_definition(self, tokens, columns):
token = None
is_constraint_definition = None
field_name = None
constraint_name = None
unique = False
unique_columns = []
check = False
check_columns = []
braces_deep = 0
for token in tokens:
if token.match(sqlparse.tokens.Punctuation, '('):
braces_deep += 1
elif token.match(sqlparse.tokens.Punctuation, ')'):
braces_deep -= 1
if braces_deep < 0:
# End of columns and constraints for table definition.
break
elif braces_deep == 0 and token.match(sqlparse.tokens.Punctuation, ','):
# End of current column or constraint definition.
break
# Detect column or constraint definition by first token.
if is_constraint_definition is None:
is_constraint_definition = token.match(sqlparse.tokens.Keyword, 'CONSTRAINT')
if is_constraint_definition:
continue
if is_constraint_definition:
# Detect constraint name by second token.
if constraint_name is None:
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
constraint_name = token.value
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
constraint_name = token.value[1:-1]
# Start constraint columns parsing after UNIQUE keyword.
if token.match(sqlparse.tokens.Keyword, 'UNIQUE'):
unique = True
unique_braces_deep = braces_deep
elif unique:
if unique_braces_deep == braces_deep:
if unique_columns:
# Stop constraint parsing.
unique = False
continue
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
unique_columns.append(token.value)
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
unique_columns.append(token.value[1:-1])
else:
# Detect field name by first token.
if field_name is None:
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
field_name = token.value
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
field_name = token.value[1:-1]
if token.match(sqlparse.tokens.Keyword, 'UNIQUE'):
unique_columns = [field_name]
# Start constraint columns parsing after CHECK keyword.
if token.match(sqlparse.tokens.Keyword, 'CHECK'):
check = True
check_braces_deep = braces_deep
elif check:
if check_braces_deep == braces_deep:
if check_columns:
# Stop constraint parsing.
check = False
continue
if token.ttype in (sqlparse.tokens.Name, sqlparse.tokens.Keyword):
if token.value in columns:
check_columns.append(token.value)
elif token.ttype == sqlparse.tokens.Literal.String.Symbol:
if token.value[1:-1] in columns:
check_columns.append(token.value[1:-1])
unique_constraint = {
'unique': True,
'columns': unique_columns,
'primary_key': False,
'foreign_key': None,
'check': False,
'index': False,
} if unique_columns else None
check_constraint = {
'check': True,
'columns': check_columns,
'primary_key': False,
'unique': False,
'foreign_key': None,
'index': False,
} if check_columns else None
return constraint_name, unique_constraint, check_constraint, token
def _parse_table_constraints(self, sql, columns):
# Check constraint parsing is based of SQLite syntax diagram.
# https://www.sqlite.org/syntaxdiagrams.html#table-constraint
statement = sqlparse.parse(sql)[0]
constraints = {}
unnamed_constrains_index = 0
tokens = (token for token in statement.flatten() if not token.is_whitespace)
# Go to columns and constraint definition
for token in tokens:
if token.match(sqlparse.tokens.Punctuation, '('):
break
# Parse columns and constraint definition
while True:
constraint_name, unique, check, end_token = self._parse_column_or_constraint_definition(tokens, columns)
if unique:
if constraint_name:
constraints[constraint_name] = unique
else:
unnamed_constrains_index += 1
constraints['__unnamed_constraint_%s__' % unnamed_constrains_index] = unique
if check:
if constraint_name:
constraints[constraint_name] = check
else:
unnamed_constrains_index += 1
constraints['__unnamed_constraint_%s__' % unnamed_constrains_index] = check
if end_token.match(sqlparse.tokens.Punctuation, ')'):
break
return constraints
def get_constraints(self, cursor, table_name):
"""
Retrieve any constraints or keys (unique, pk, fk, check, index) across
one or more columns.
"""
constraints = {}
# Find inline check constraints.
try:
table_schema = cursor.execute(
"SELECT sql FROM sqlite_master WHERE type='table' and name=%s" % (
self.connection.ops.quote_name(table_name),
)
).fetchone()[0]
except TypeError:
# table_name is a view.
pass
else:
columns = {info.name for info in self.get_table_description(cursor, table_name)}
constraints.update(self._parse_table_constraints(table_schema, columns))
# Get the index info
cursor.execute("PRAGMA index_list(%s)" % self.connection.ops.quote_name(table_name))
for row in cursor.fetchall():
# SQLite 3.8.9+ has 5 columns, however older versions only give 3
# columns. Discard last 2 columns if there.
number, index, unique = row[:3]
cursor.execute(
"SELECT sql FROM sqlite_master "
"WHERE type='index' AND name=%s" % self.connection.ops.quote_name(index)
)
# There's at most one row.
sql, = cursor.fetchone() or (None,)
# Inline constraints are already detected in
# _parse_table_constraints(). The reasons to avoid fetching inline
# constraints from `PRAGMA index_list` are:
# - Inline constraints can have a different name and information
# than what `PRAGMA index_list` gives.
# - Not all inline constraints may appear in `PRAGMA index_list`.
if not sql:
# An inline constraint
continue
# Get the index info for that index
cursor.execute('PRAGMA index_info(%s)' % self.connection.ops.quote_name(index))
for index_rank, column_rank, column in cursor.fetchall():
if index not in constraints:
constraints[index] = {
"columns": [],
"primary_key": False,
"unique": bool(unique),
"foreign_key": None,
"check": False,
"index": True,
}
constraints[index]['columns'].append(column)
# Add type and column orders for indexes
if constraints[index]['index']:
# SQLite doesn't support any index type other than b-tree
constraints[index]['type'] = Index.suffix
orders = self._get_index_columns_orders(sql)
if orders is not None:
constraints[index]['orders'] = orders
# Get the PK
pk_column = self.get_primary_key_column(cursor, table_name)
if pk_column:
# SQLite doesn't actually give a name to the PK constraint,
# so we invent one. This is fine, as the SQLite backend never
# deletes PK constraints by name, as you can't delete constraints
# in SQLite; we remake the table with a new PK instead.
constraints["__primary__"] = {
"columns": [pk_column],
"primary_key": True,
"unique": False, # It's not actually a unique constraint.
"foreign_key": None,
"check": False,
"index": False,
}
relations = enumerate(self.get_relations(cursor, table_name).items())
constraints.update({
f'fk_{index}': {
'columns': [column_name],
'primary_key': False,
'unique': False,
'foreign_key': (ref_table_name, ref_column_name),
'check': False,
'index': False,
}
for index, (column_name, (ref_column_name, ref_table_name)) in relations
})
return constraints
def _get_index_columns_orders(self, sql):
tokens = sqlparse.parse(sql)[0]
for token in tokens:
if isinstance(token, sqlparse.sql.Parenthesis):
columns = str(token).strip('()').split(', ')
return ['DESC' if info.endswith('DESC') else 'ASC' for info in columns]
return None
def _get_column_collations(self, cursor, table_name):
row = cursor.execute("""
SELECT sql
FROM sqlite_master
WHERE type = 'table' AND name = %s
""", [table_name]).fetchone()
if not row:
return {}
sql = row[0]
columns = str(sqlparse.parse(sql)[0][-1]).strip('()').split(', ')
collations = {}
for column in columns:
tokens = column[1:].split()
column_name = tokens[0].strip('"')
for index, token in enumerate(tokens):
if token == 'COLLATE':
collation = tokens[index + 1]
break
else:
collation = None
collations[column_name] = collation
return collations
|
b73bc1e9c90d56025c7dd416c20405bbb48b7d9147dd421cdaef5e4d263c247b | """
SQLite backend for the sqlite3 module in the standard library.
"""
import decimal
import warnings
from itertools import chain
from sqlite3 import dbapi2 as Database
from django.core.exceptions import ImproperlyConfigured
from django.db import IntegrityError
from django.db.backends.base.base import BaseDatabaseWrapper
from django.utils.asyncio import async_unsafe
from django.utils.dateparse import parse_datetime, parse_time
from django.utils.regex_helper import _lazy_re_compile
from ._functions import register as register_functions
from .client import DatabaseClient
from .creation import DatabaseCreation
from .features import DatabaseFeatures
from .introspection import DatabaseIntrospection
from .operations import DatabaseOperations
from .schema import DatabaseSchemaEditor
def decoder(conv_func):
"""
Convert bytestrings from Python's sqlite3 interface to a regular string.
"""
return lambda s: conv_func(s.decode())
def check_sqlite_version():
if Database.sqlite_version_info < (3, 9, 0):
raise ImproperlyConfigured(
'SQLite 3.9.0 or later is required (found %s).' % Database.sqlite_version
)
check_sqlite_version()
Database.register_converter("bool", b'1'.__eq__)
Database.register_converter("time", decoder(parse_time))
Database.register_converter("datetime", decoder(parse_datetime))
Database.register_converter("timestamp", decoder(parse_datetime))
Database.register_adapter(decimal.Decimal, str)
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'sqlite'
display_name = 'SQLite'
# SQLite doesn't actually support most of these types, but it "does the right
# thing" given more verbose field definitions, so leave them as is so that
# schema inspection is more useful.
data_types = {
'AutoField': 'integer',
'BigAutoField': 'integer',
'BinaryField': 'BLOB',
'BooleanField': 'bool',
'CharField': 'varchar(%(max_length)s)',
'DateField': 'date',
'DateTimeField': 'datetime',
'DecimalField': 'decimal',
'DurationField': 'bigint',
'FileField': 'varchar(%(max_length)s)',
'FilePathField': 'varchar(%(max_length)s)',
'FloatField': 'real',
'IntegerField': 'integer',
'BigIntegerField': 'bigint',
'IPAddressField': 'char(15)',
'GenericIPAddressField': 'char(39)',
'JSONField': 'text',
'OneToOneField': 'integer',
'PositiveBigIntegerField': 'bigint unsigned',
'PositiveIntegerField': 'integer unsigned',
'PositiveSmallIntegerField': 'smallint unsigned',
'SlugField': 'varchar(%(max_length)s)',
'SmallAutoField': 'integer',
'SmallIntegerField': 'smallint',
'TextField': 'text',
'TimeField': 'time',
'UUIDField': 'char(32)',
}
data_type_check_constraints = {
'PositiveBigIntegerField': '"%(column)s" >= 0',
'JSONField': '(JSON_VALID("%(column)s") OR "%(column)s" IS NULL)',
'PositiveIntegerField': '"%(column)s" >= 0',
'PositiveSmallIntegerField': '"%(column)s" >= 0',
}
data_types_suffix = {
'AutoField': 'AUTOINCREMENT',
'BigAutoField': 'AUTOINCREMENT',
'SmallAutoField': 'AUTOINCREMENT',
}
# SQLite requires LIKE statements to include an ESCAPE clause if the value
# being escaped has a percent or underscore in it.
# See https://www.sqlite.org/lang_expr.html for an explanation.
operators = {
'exact': '= %s',
'iexact': "LIKE %s ESCAPE '\\'",
'contains': "LIKE %s ESCAPE '\\'",
'icontains': "LIKE %s ESCAPE '\\'",
'regex': 'REGEXP %s',
'iregex': "REGEXP '(?i)' || %s",
'gt': '> %s',
'gte': '>= %s',
'lt': '< %s',
'lte': '<= %s',
'startswith': "LIKE %s ESCAPE '\\'",
'endswith': "LIKE %s ESCAPE '\\'",
'istartswith': "LIKE %s ESCAPE '\\'",
'iendswith': "LIKE %s ESCAPE '\\'",
}
# The patterns below are used to generate SQL pattern lookup clauses when
# the right-hand side of the lookup isn't a raw string (it might be an expression
# or the result of a bilateral transformation).
# In those cases, special characters for LIKE operators (e.g. \, *, _) should be
# escaped on database side.
#
# Note: we use str.format() here for readability as '%' is used as a wildcard for
# the LIKE operator.
pattern_esc = r"REPLACE(REPLACE(REPLACE({}, '\', '\\'), '%%', '\%%'), '_', '\_')"
pattern_ops = {
'contains': r"LIKE '%%' || {} || '%%' ESCAPE '\'",
'icontains': r"LIKE '%%' || UPPER({}) || '%%' ESCAPE '\'",
'startswith': r"LIKE {} || '%%' ESCAPE '\'",
'istartswith': r"LIKE UPPER({}) || '%%' ESCAPE '\'",
'endswith': r"LIKE '%%' || {} ESCAPE '\'",
'iendswith': r"LIKE '%%' || UPPER({}) ESCAPE '\'",
}
Database = Database
SchemaEditorClass = DatabaseSchemaEditor
# Classes instantiated in __init__().
client_class = DatabaseClient
creation_class = DatabaseCreation
features_class = DatabaseFeatures
introspection_class = DatabaseIntrospection
ops_class = DatabaseOperations
def get_connection_params(self):
settings_dict = self.settings_dict
if not settings_dict['NAME']:
raise ImproperlyConfigured(
"settings.DATABASES is improperly configured. "
"Please supply the NAME value.")
kwargs = {
'database': settings_dict['NAME'],
'detect_types': Database.PARSE_DECLTYPES | Database.PARSE_COLNAMES,
**settings_dict['OPTIONS'],
}
# Always allow the underlying SQLite connection to be shareable
# between multiple threads. The safe-guarding will be handled at a
# higher level by the `BaseDatabaseWrapper.allow_thread_sharing`
# property. This is necessary as the shareability is disabled by
# default in pysqlite and it cannot be changed once a connection is
# opened.
if 'check_same_thread' in kwargs and kwargs['check_same_thread']:
warnings.warn(
'The `check_same_thread` option was provided and set to '
'True. It will be overridden with False. Use the '
'`DatabaseWrapper.allow_thread_sharing` property instead '
'for controlling thread shareability.',
RuntimeWarning
)
kwargs.update({'check_same_thread': False, 'uri': True})
return kwargs
@async_unsafe
def get_new_connection(self, conn_params):
conn = Database.connect(**conn_params)
register_functions(conn)
conn.execute('PRAGMA foreign_keys = ON')
# The macOS bundled SQLite defaults legacy_alter_table ON, which
# prevents atomic table renames (feature supports_atomic_references_rename)
conn.execute('PRAGMA legacy_alter_table = OFF')
return conn
def init_connection_state(self):
pass
def create_cursor(self, name=None):
return self.connection.cursor(factory=SQLiteCursorWrapper)
@async_unsafe
def close(self):
self.validate_thread_sharing()
# If database is in memory, closing the connection destroys the
# database. To prevent accidental data loss, ignore close requests on
# an in-memory db.
if not self.is_in_memory_db():
BaseDatabaseWrapper.close(self)
def _savepoint_allowed(self):
# When 'isolation_level' is not None, sqlite3 commits before each
# savepoint; it's a bug. When it is None, savepoints don't make sense
# because autocommit is enabled. The only exception is inside 'atomic'
# blocks. To work around that bug, on SQLite, 'atomic' starts a
# transaction explicitly rather than simply disable autocommit.
return self.in_atomic_block
def _set_autocommit(self, autocommit):
if autocommit:
level = None
else:
# sqlite3's internal default is ''. It's different from None.
# See Modules/_sqlite/connection.c.
level = ''
# 'isolation_level' is a misleading API.
# SQLite always runs at the SERIALIZABLE isolation level.
with self.wrap_database_errors:
self.connection.isolation_level = level
def disable_constraint_checking(self):
with self.cursor() as cursor:
cursor.execute('PRAGMA foreign_keys = OFF')
# Foreign key constraints cannot be turned off while in a multi-
# statement transaction. Fetch the current state of the pragma
# to determine if constraints are effectively disabled.
enabled = cursor.execute('PRAGMA foreign_keys').fetchone()[0]
return not bool(enabled)
def enable_constraint_checking(self):
with self.cursor() as cursor:
cursor.execute('PRAGMA foreign_keys = ON')
def check_constraints(self, table_names=None):
"""
Check each table name in `table_names` for rows with invalid foreign
key references. This method is intended to be used in conjunction with
`disable_constraint_checking()` and `enable_constraint_checking()`, to
determine if rows with invalid references were entered while constraint
checks were off.
"""
if self.features.supports_pragma_foreign_key_check:
with self.cursor() as cursor:
if table_names is None:
violations = cursor.execute('PRAGMA foreign_key_check').fetchall()
else:
violations = chain.from_iterable(
cursor.execute(
'PRAGMA foreign_key_check(%s)'
% self.ops.quote_name(table_name)
).fetchall()
for table_name in table_names
)
# See https://www.sqlite.org/pragma.html#pragma_foreign_key_check
for table_name, rowid, referenced_table_name, foreign_key_index in violations:
foreign_key = cursor.execute(
'PRAGMA foreign_key_list(%s)' % self.ops.quote_name(table_name)
).fetchall()[foreign_key_index]
column_name, referenced_column_name = foreign_key[3:5]
primary_key_column_name = self.introspection.get_primary_key_column(cursor, table_name)
primary_key_value, bad_value = cursor.execute(
'SELECT %s, %s FROM %s WHERE rowid = %%s' % (
self.ops.quote_name(primary_key_column_name),
self.ops.quote_name(column_name),
self.ops.quote_name(table_name),
),
(rowid,),
).fetchone()
raise IntegrityError(
"The row in table '%s' with primary key '%s' has an "
"invalid foreign key: %s.%s contains a value '%s' that "
"does not have a corresponding value in %s.%s." % (
table_name, primary_key_value, table_name, column_name,
bad_value, referenced_table_name, referenced_column_name
)
)
else:
with self.cursor() as cursor:
if table_names is None:
table_names = self.introspection.table_names(cursor)
for table_name in table_names:
primary_key_column_name = self.introspection.get_primary_key_column(cursor, table_name)
if not primary_key_column_name:
continue
relations = self.introspection.get_relations(cursor, table_name)
for column_name, (referenced_column_name, referenced_table_name) in relations:
cursor.execute(
"""
SELECT REFERRING.`%s`, REFERRING.`%s` FROM `%s` as REFERRING
LEFT JOIN `%s` as REFERRED
ON (REFERRING.`%s` = REFERRED.`%s`)
WHERE REFERRING.`%s` IS NOT NULL AND REFERRED.`%s` IS NULL
"""
% (
primary_key_column_name, column_name, table_name,
referenced_table_name, column_name, referenced_column_name,
column_name, referenced_column_name,
)
)
for bad_row in cursor.fetchall():
raise IntegrityError(
"The row in table '%s' with primary key '%s' has an "
"invalid foreign key: %s.%s contains a value '%s' that "
"does not have a corresponding value in %s.%s." % (
table_name, bad_row[0], table_name, column_name,
bad_row[1], referenced_table_name, referenced_column_name,
)
)
def is_usable(self):
return True
def _start_transaction_under_autocommit(self):
"""
Start a transaction explicitly in autocommit mode.
Staying in autocommit mode works around a bug of sqlite3 that breaks
savepoints when autocommit is disabled.
"""
self.cursor().execute("BEGIN")
def is_in_memory_db(self):
return self.creation.is_in_memory_db(self.settings_dict['NAME'])
FORMAT_QMARK_REGEX = _lazy_re_compile(r'(?<!%)%s')
class SQLiteCursorWrapper(Database.Cursor):
"""
Django uses "format" style placeholders, but pysqlite2 uses "qmark" style.
This fixes it -- but note that if you want to use a literal "%s" in a query,
you'll need to use "%%s".
"""
def execute(self, query, params=None):
if params is None:
return Database.Cursor.execute(self, query)
query = self.convert_query(query)
return Database.Cursor.execute(self, query, params)
def executemany(self, query, param_list):
query = self.convert_query(query)
return Database.Cursor.executemany(self, query, param_list)
def convert_query(self, query):
return FORMAT_QMARK_REGEX.sub('?', query).replace('%%', '%')
|
5e09a72472278a98361c0823b26aee54495e059b26029fc3aac5e62a9d60cd50 | import datetime
import decimal
import uuid
from functools import lru_cache
from itertools import chain
from django.conf import settings
from django.core.exceptions import FieldError
from django.db import DatabaseError, NotSupportedError, models
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.models.constants import OnConflict
from django.db.models.expressions import Col
from django.utils import timezone
from django.utils.dateparse import parse_date, parse_datetime, parse_time
from django.utils.functional import cached_property
class DatabaseOperations(BaseDatabaseOperations):
cast_char_field_without_max_length = 'text'
cast_data_types = {
'DateField': 'TEXT',
'DateTimeField': 'TEXT',
}
explain_prefix = 'EXPLAIN QUERY PLAN'
# List of datatypes to that cannot be extracted with JSON_EXTRACT() on
# SQLite. Use JSON_TYPE() instead.
jsonfield_datatype_values = frozenset(['null', 'false', 'true'])
def bulk_batch_size(self, fields, objs):
"""
SQLite has a compile-time default (SQLITE_LIMIT_VARIABLE_NUMBER) of
999 variables per query.
If there's only a single field to insert, the limit is 500
(SQLITE_MAX_COMPOUND_SELECT).
"""
if len(fields) == 1:
return 500
elif len(fields) > 1:
return self.connection.features.max_query_params // len(fields)
else:
return len(objs)
def check_expression_support(self, expression):
bad_fields = (models.DateField, models.DateTimeField, models.TimeField)
bad_aggregates = (models.Sum, models.Avg, models.Variance, models.StdDev)
if isinstance(expression, bad_aggregates):
for expr in expression.get_source_expressions():
try:
output_field = expr.output_field
except (AttributeError, FieldError):
# Not every subexpression has an output_field which is fine
# to ignore.
pass
else:
if isinstance(output_field, bad_fields):
raise NotSupportedError(
'You cannot use Sum, Avg, StdDev, and Variance '
'aggregations on date/time fields in sqlite3 '
'since date/time is saved as text.'
)
if (
isinstance(expression, models.Aggregate) and
expression.distinct and
len(expression.source_expressions) > 1
):
raise NotSupportedError(
"SQLite doesn't support DISTINCT on aggregate functions "
"accepting multiple arguments."
)
def date_extract_sql(self, lookup_type, field_name):
"""
Support EXTRACT with a user-defined function django_date_extract()
that's registered in connect(). Use single quotes because this is a
string and could otherwise cause a collision with a field name.
"""
return "django_date_extract('%s', %s)" % (lookup_type.lower(), field_name)
def fetch_returned_insert_rows(self, cursor):
"""
Given a cursor object that has just performed an INSERT...RETURNING
statement into a table, return the list of returned data.
"""
return cursor.fetchall()
def format_for_duration_arithmetic(self, sql):
"""Do nothing since formatting is handled in the custom function."""
return sql
def date_trunc_sql(self, lookup_type, field_name, tzname=None):
return "django_date_trunc('%s', %s, %s, %s)" % (
lookup_type.lower(),
field_name,
*self._convert_tznames_to_sql(tzname),
)
def time_trunc_sql(self, lookup_type, field_name, tzname=None):
return "django_time_trunc('%s', %s, %s, %s)" % (
lookup_type.lower(),
field_name,
*self._convert_tznames_to_sql(tzname),
)
def _convert_tznames_to_sql(self, tzname):
if tzname and settings.USE_TZ:
return "'%s'" % tzname, "'%s'" % self.connection.timezone_name
return 'NULL', 'NULL'
def datetime_cast_date_sql(self, field_name, tzname):
return 'django_datetime_cast_date(%s, %s, %s)' % (
field_name, *self._convert_tznames_to_sql(tzname),
)
def datetime_cast_time_sql(self, field_name, tzname):
return 'django_datetime_cast_time(%s, %s, %s)' % (
field_name, *self._convert_tznames_to_sql(tzname),
)
def datetime_extract_sql(self, lookup_type, field_name, tzname):
return "django_datetime_extract('%s', %s, %s, %s)" % (
lookup_type.lower(), field_name, *self._convert_tznames_to_sql(tzname),
)
def datetime_trunc_sql(self, lookup_type, field_name, tzname):
return "django_datetime_trunc('%s', %s, %s, %s)" % (
lookup_type.lower(), field_name, *self._convert_tznames_to_sql(tzname),
)
def time_extract_sql(self, lookup_type, field_name):
return "django_time_extract('%s', %s)" % (lookup_type.lower(), field_name)
def pk_default_value(self):
return "NULL"
def _quote_params_for_last_executed_query(self, params):
"""
Only for last_executed_query! Don't use this to execute SQL queries!
"""
# This function is limited both by SQLITE_LIMIT_VARIABLE_NUMBER (the
# number of parameters, default = 999) and SQLITE_MAX_COLUMN (the
# number of return values, default = 2000). Since Python's sqlite3
# module doesn't expose the get_limit() C API, assume the default
# limits are in effect and split the work in batches if needed.
BATCH_SIZE = 999
if len(params) > BATCH_SIZE:
results = ()
for index in range(0, len(params), BATCH_SIZE):
chunk = params[index:index + BATCH_SIZE]
results += self._quote_params_for_last_executed_query(chunk)
return results
sql = 'SELECT ' + ', '.join(['QUOTE(?)'] * len(params))
# Bypass Django's wrappers and use the underlying sqlite3 connection
# to avoid logging this query - it would trigger infinite recursion.
cursor = self.connection.connection.cursor()
# Native sqlite3 cursors cannot be used as context managers.
try:
return cursor.execute(sql, params).fetchone()
finally:
cursor.close()
def last_executed_query(self, cursor, sql, params):
# Python substitutes parameters in Modules/_sqlite/cursor.c with:
# pysqlite_statement_bind_parameters(self->statement, parameters, allow_8bit_chars);
# Unfortunately there is no way to reach self->statement from Python,
# so we quote and substitute parameters manually.
if params:
if isinstance(params, (list, tuple)):
params = self._quote_params_for_last_executed_query(params)
else:
values = tuple(params.values())
values = self._quote_params_for_last_executed_query(values)
params = dict(zip(params, values))
return sql % params
# For consistency with SQLiteCursorWrapper.execute(), just return sql
# when there are no parameters. See #13648 and #17158.
else:
return sql
def quote_name(self, name):
if name.startswith('"') and name.endswith('"'):
return name # Quoting once is enough.
return '"%s"' % name
def no_limit_value(self):
return -1
def __references_graph(self, table_name):
query = """
WITH tables AS (
SELECT %s name
UNION
SELECT sqlite_master.name
FROM sqlite_master
JOIN tables ON (sql REGEXP %s || tables.name || %s)
) SELECT name FROM tables;
"""
params = (
table_name,
r'(?i)\s+references\s+("|\')?',
r'("|\')?\s*\(',
)
with self.connection.cursor() as cursor:
results = cursor.execute(query, params)
return [row[0] for row in results.fetchall()]
@cached_property
def _references_graph(self):
# 512 is large enough to fit the ~330 tables (as of this writing) in
# Django's test suite.
return lru_cache(maxsize=512)(self.__references_graph)
def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):
if tables and allow_cascade:
# Simulate TRUNCATE CASCADE by recursively collecting the tables
# referencing the tables to be flushed.
tables = set(chain.from_iterable(self._references_graph(table) for table in tables))
sql = ['%s %s %s;' % (
style.SQL_KEYWORD('DELETE'),
style.SQL_KEYWORD('FROM'),
style.SQL_FIELD(self.quote_name(table))
) for table in tables]
if reset_sequences:
sequences = [{'table': table} for table in tables]
sql.extend(self.sequence_reset_by_name_sql(style, sequences))
return sql
def sequence_reset_by_name_sql(self, style, sequences):
if not sequences:
return []
return [
'%s %s %s %s = 0 %s %s %s (%s);' % (
style.SQL_KEYWORD('UPDATE'),
style.SQL_TABLE(self.quote_name('sqlite_sequence')),
style.SQL_KEYWORD('SET'),
style.SQL_FIELD(self.quote_name('seq')),
style.SQL_KEYWORD('WHERE'),
style.SQL_FIELD(self.quote_name('name')),
style.SQL_KEYWORD('IN'),
', '.join([
"'%s'" % sequence_info['table'] for sequence_info in sequences
]),
),
]
def adapt_datetimefield_value(self, value):
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
# SQLite doesn't support tz-aware datetimes
if timezone.is_aware(value):
if settings.USE_TZ:
value = timezone.make_naive(value, self.connection.timezone)
else:
raise ValueError("SQLite backend does not support timezone-aware datetimes when USE_TZ is False.")
return str(value)
def adapt_timefield_value(self, value):
if value is None:
return None
# Expression values are adapted by the database.
if hasattr(value, 'resolve_expression'):
return value
# SQLite doesn't support tz-aware datetimes
if timezone.is_aware(value):
raise ValueError("SQLite backend does not support timezone-aware times.")
return str(value)
def get_db_converters(self, expression):
converters = super().get_db_converters(expression)
internal_type = expression.output_field.get_internal_type()
if internal_type == 'DateTimeField':
converters.append(self.convert_datetimefield_value)
elif internal_type == 'DateField':
converters.append(self.convert_datefield_value)
elif internal_type == 'TimeField':
converters.append(self.convert_timefield_value)
elif internal_type == 'DecimalField':
converters.append(self.get_decimalfield_converter(expression))
elif internal_type == 'UUIDField':
converters.append(self.convert_uuidfield_value)
elif internal_type == 'BooleanField':
converters.append(self.convert_booleanfield_value)
return converters
def convert_datetimefield_value(self, value, expression, connection):
if value is not None:
if not isinstance(value, datetime.datetime):
value = parse_datetime(value)
if settings.USE_TZ and not timezone.is_aware(value):
value = timezone.make_aware(value, self.connection.timezone)
return value
def convert_datefield_value(self, value, expression, connection):
if value is not None:
if not isinstance(value, datetime.date):
value = parse_date(value)
return value
def convert_timefield_value(self, value, expression, connection):
if value is not None:
if not isinstance(value, datetime.time):
value = parse_time(value)
return value
def get_decimalfield_converter(self, expression):
# SQLite stores only 15 significant digits. Digits coming from
# float inaccuracy must be removed.
create_decimal = decimal.Context(prec=15).create_decimal_from_float
if isinstance(expression, Col):
quantize_value = decimal.Decimal(1).scaleb(-expression.output_field.decimal_places)
def converter(value, expression, connection):
if value is not None:
return create_decimal(value).quantize(quantize_value, context=expression.output_field.context)
else:
def converter(value, expression, connection):
if value is not None:
return create_decimal(value)
return converter
def convert_uuidfield_value(self, value, expression, connection):
if value is not None:
value = uuid.UUID(value)
return value
def convert_booleanfield_value(self, value, expression, connection):
return bool(value) if value in (1, 0) else value
def bulk_insert_sql(self, fields, placeholder_rows):
placeholder_rows_sql = (', '.join(row) for row in placeholder_rows)
values_sql = ', '.join(f'({sql})' for sql in placeholder_rows_sql)
return f'VALUES {values_sql}'
def combine_expression(self, connector, sub_expressions):
# SQLite doesn't have a ^ operator, so use the user-defined POWER
# function that's registered in connect().
if connector == '^':
return 'POWER(%s)' % ','.join(sub_expressions)
elif connector == '#':
return 'BITXOR(%s)' % ','.join(sub_expressions)
return super().combine_expression(connector, sub_expressions)
def combine_duration_expression(self, connector, sub_expressions):
if connector not in ['+', '-', '*', '/']:
raise DatabaseError('Invalid connector for timedelta: %s.' % connector)
fn_params = ["'%s'" % connector] + sub_expressions
if len(fn_params) > 3:
raise ValueError('Too many params for timedelta operations.')
return "django_format_dtdelta(%s)" % ', '.join(fn_params)
def integer_field_range(self, internal_type):
# SQLite doesn't enforce any integer constraints
return (None, None)
def subtract_temporals(self, internal_type, lhs, rhs):
lhs_sql, lhs_params = lhs
rhs_sql, rhs_params = rhs
params = (*lhs_params, *rhs_params)
if internal_type == 'TimeField':
return 'django_time_diff(%s, %s)' % (lhs_sql, rhs_sql), params
return 'django_timestamp_diff(%s, %s)' % (lhs_sql, rhs_sql), params
def insert_statement(self, on_conflict=None):
if on_conflict == OnConflict.IGNORE:
return 'INSERT OR IGNORE INTO'
return super().insert_statement(on_conflict=on_conflict)
def return_insert_columns(self, fields):
# SQLite < 3.35 doesn't support an INSERT...RETURNING statement.
if not fields:
return '', ()
columns = [
'%s.%s' % (
self.quote_name(field.model._meta.db_table),
self.quote_name(field.column),
) for field in fields
]
return 'RETURNING %s' % ', '.join(columns), ()
def on_conflict_suffix_sql(self, fields, on_conflict, update_fields, unique_fields):
if (
on_conflict == OnConflict.UPDATE and
self.connection.features.supports_update_conflicts_with_target
):
return 'ON CONFLICT(%s) DO UPDATE SET %s' % (
', '.join(map(self.quote_name, unique_fields)),
', '.join([
f'{field} = EXCLUDED.{field}'
for field in map(self.quote_name, update_fields)
]),
)
return super().on_conflict_suffix_sql(
fields, on_conflict, update_fields, unique_fields,
)
|
70e0ea0441005cf5b4615ea636d6bc071b67855745098ad0183ba45190f9bf97 | import copy
from decimal import Decimal
from django.apps.registry import Apps
from django.db import NotSupportedError
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.backends.ddl_references import Statement
from django.db.backends.utils import strip_quotes
from django.db.models import UniqueConstraint
from django.db.transaction import atomic
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
sql_delete_table = "DROP TABLE %(table)s"
sql_create_fk = None
sql_create_inline_fk = "REFERENCES %(to_table)s (%(to_column)s) DEFERRABLE INITIALLY DEFERRED"
sql_create_column_inline_fk = sql_create_inline_fk
sql_create_unique = "CREATE UNIQUE INDEX %(name)s ON %(table)s (%(columns)s)"
sql_delete_unique = "DROP INDEX %(name)s"
def __enter__(self):
# Some SQLite schema alterations need foreign key constraints to be
# disabled. Enforce it here for the duration of the schema edition.
if not self.connection.disable_constraint_checking():
raise NotSupportedError(
'SQLite schema editor cannot be used while foreign key '
'constraint checks are enabled. Make sure to disable them '
'before entering a transaction.atomic() context because '
'SQLite does not support disabling them in the middle of '
'a multi-statement transaction.'
)
return super().__enter__()
def __exit__(self, exc_type, exc_value, traceback):
self.connection.check_constraints()
super().__exit__(exc_type, exc_value, traceback)
self.connection.enable_constraint_checking()
def quote_value(self, value):
# The backend "mostly works" without this function and there are use
# cases for compiling Python without the sqlite3 libraries (e.g.
# security hardening).
try:
import sqlite3
value = sqlite3.adapt(value)
except ImportError:
pass
except sqlite3.ProgrammingError:
pass
# Manual emulation of SQLite parameter quoting
if isinstance(value, bool):
return str(int(value))
elif isinstance(value, (Decimal, float, int)):
return str(value)
elif isinstance(value, str):
return "'%s'" % value.replace("\'", "\'\'")
elif value is None:
return "NULL"
elif isinstance(value, (bytes, bytearray, memoryview)):
# Bytes are only allowed for BLOB fields, encoded as string
# literals containing hexadecimal data and preceded by a single "X"
# character.
return "X'%s'" % value.hex()
else:
raise ValueError("Cannot quote parameter value %r of type %s" % (value, type(value)))
def prepare_default(self, value):
return self.quote_value(value)
def _is_referenced_by_fk_constraint(self, table_name, column_name=None, ignore_self=False):
"""
Return whether or not the provided table name is referenced by another
one. If `column_name` is specified, only references pointing to that
column are considered. If `ignore_self` is True, self-referential
constraints are ignored.
"""
with self.connection.cursor() as cursor:
for other_table in self.connection.introspection.get_table_list(cursor):
if ignore_self and other_table.name == table_name:
continue
relations = self.connection.introspection.get_relations(cursor, other_table.name)
for constraint_column, constraint_table in relations.values():
if (constraint_table == table_name and
(column_name is None or constraint_column == column_name)):
return True
return False
def alter_db_table(self, model, old_db_table, new_db_table, disable_constraints=True):
if (not self.connection.features.supports_atomic_references_rename and
disable_constraints and self._is_referenced_by_fk_constraint(old_db_table)):
if self.connection.in_atomic_block:
raise NotSupportedError((
'Renaming the %r table while in a transaction is not '
'supported on SQLite < 3.26 because it would break referential '
'integrity. Try adding `atomic = False` to the Migration class.'
) % old_db_table)
self.connection.enable_constraint_checking()
super().alter_db_table(model, old_db_table, new_db_table)
self.connection.disable_constraint_checking()
else:
super().alter_db_table(model, old_db_table, new_db_table)
def alter_field(self, model, old_field, new_field, strict=False):
if not self._field_should_be_altered(old_field, new_field):
return
old_field_name = old_field.name
table_name = model._meta.db_table
_, old_column_name = old_field.get_attname_column()
if (new_field.name != old_field_name and
not self.connection.features.supports_atomic_references_rename and
self._is_referenced_by_fk_constraint(table_name, old_column_name, ignore_self=True)):
if self.connection.in_atomic_block:
raise NotSupportedError((
'Renaming the %r.%r column while in a transaction is not '
'supported on SQLite < 3.26 because it would break referential '
'integrity. Try adding `atomic = False` to the Migration class.'
) % (model._meta.db_table, old_field_name))
with atomic(self.connection.alias):
super().alter_field(model, old_field, new_field, strict=strict)
# Follow SQLite's documented procedure for performing changes
# that don't affect the on-disk content.
# https://sqlite.org/lang_altertable.html#otheralter
with self.connection.cursor() as cursor:
schema_version = cursor.execute('PRAGMA schema_version').fetchone()[0]
cursor.execute('PRAGMA writable_schema = 1')
references_template = ' REFERENCES "%s" ("%%s") ' % table_name
new_column_name = new_field.get_attname_column()[1]
search = references_template % old_column_name
replacement = references_template % new_column_name
cursor.execute('UPDATE sqlite_master SET sql = replace(sql, %s, %s)', (search, replacement))
cursor.execute('PRAGMA schema_version = %d' % (schema_version + 1))
cursor.execute('PRAGMA writable_schema = 0')
# The integrity check will raise an exception and rollback
# the transaction if the sqlite_master updates corrupt the
# database.
cursor.execute('PRAGMA integrity_check')
# Perform a VACUUM to refresh the database representation from
# the sqlite_master table.
with self.connection.cursor() as cursor:
cursor.execute('VACUUM')
else:
super().alter_field(model, old_field, new_field, strict=strict)
def _remake_table(self, model, create_field=None, delete_field=None, alter_field=None):
"""
Shortcut to transform a model from old_model into new_model
This follows the correct procedure to perform non-rename or column
addition operations based on SQLite's documentation
https://www.sqlite.org/lang_altertable.html#caution
The essential steps are:
1. Create a table with the updated definition called "new__app_model"
2. Copy the data from the existing "app_model" table to the new table
3. Drop the "app_model" table
4. Rename the "new__app_model" table to "app_model"
5. Restore any index of the previous "app_model" table.
"""
# Self-referential fields must be recreated rather than copied from
# the old model to ensure their remote_field.field_name doesn't refer
# to an altered field.
def is_self_referential(f):
return f.is_relation and f.remote_field.model is model
# Work out the new fields dict / mapping
body = {
f.name: f.clone() if is_self_referential(f) else f
for f in model._meta.local_concrete_fields
}
# Since mapping might mix column names and default values,
# its values must be already quoted.
mapping = {f.column: self.quote_name(f.column) for f in model._meta.local_concrete_fields}
# This maps field names (not columns) for things like unique_together
rename_mapping = {}
# If any of the new or altered fields is introducing a new PK,
# remove the old one
restore_pk_field = None
if getattr(create_field, 'primary_key', False) or (
alter_field and getattr(alter_field[1], 'primary_key', False)):
for name, field in list(body.items()):
if field.primary_key:
field.primary_key = False
restore_pk_field = field
if field.auto_created:
del body[name]
del mapping[field.column]
# Add in any created fields
if create_field:
body[create_field.name] = create_field
# Choose a default and insert it into the copy map
if not create_field.many_to_many and create_field.concrete:
mapping[create_field.column] = self.prepare_default(
self.effective_default(create_field),
)
# Add in any altered fields
if alter_field:
old_field, new_field = alter_field
body.pop(old_field.name, None)
mapping.pop(old_field.column, None)
body[new_field.name] = new_field
if old_field.null and not new_field.null:
case_sql = "coalesce(%(col)s, %(default)s)" % {
'col': self.quote_name(old_field.column),
'default': self.prepare_default(self.effective_default(new_field)),
}
mapping[new_field.column] = case_sql
else:
mapping[new_field.column] = self.quote_name(old_field.column)
rename_mapping[old_field.name] = new_field.name
# Remove any deleted fields
if delete_field:
del body[delete_field.name]
del mapping[delete_field.column]
# Remove any implicit M2M tables
if delete_field.many_to_many and delete_field.remote_field.through._meta.auto_created:
return self.delete_model(delete_field.remote_field.through)
# Work inside a new app registry
apps = Apps()
# Work out the new value of unique_together, taking renames into
# account
unique_together = [
[rename_mapping.get(n, n) for n in unique]
for unique in model._meta.unique_together
]
# Work out the new value for index_together, taking renames into
# account
index_together = [
[rename_mapping.get(n, n) for n in index]
for index in model._meta.index_together
]
indexes = model._meta.indexes
if delete_field:
indexes = [
index for index in indexes
if delete_field.name not in index.fields
]
constraints = list(model._meta.constraints)
# Provide isolated instances of the fields to the new model body so
# that the existing model's internals aren't interfered with when
# the dummy model is constructed.
body_copy = copy.deepcopy(body)
# Construct a new model with the new fields to allow self referential
# primary key to resolve to. This model won't ever be materialized as a
# table and solely exists for foreign key reference resolution purposes.
# This wouldn't be required if the schema editor was operating on model
# states instead of rendered models.
meta_contents = {
'app_label': model._meta.app_label,
'db_table': model._meta.db_table,
'unique_together': unique_together,
'index_together': index_together,
'indexes': indexes,
'constraints': constraints,
'apps': apps,
}
meta = type("Meta", (), meta_contents)
body_copy['Meta'] = meta
body_copy['__module__'] = model.__module__
type(model._meta.object_name, model.__bases__, body_copy)
# Construct a model with a renamed table name.
body_copy = copy.deepcopy(body)
meta_contents = {
'app_label': model._meta.app_label,
'db_table': 'new__%s' % strip_quotes(model._meta.db_table),
'unique_together': unique_together,
'index_together': index_together,
'indexes': indexes,
'constraints': constraints,
'apps': apps,
}
meta = type("Meta", (), meta_contents)
body_copy['Meta'] = meta
body_copy['__module__'] = model.__module__
new_model = type('New%s' % model._meta.object_name, model.__bases__, body_copy)
# Create a new table with the updated schema.
self.create_model(new_model)
# Copy data from the old table into the new table
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
self.quote_name(new_model._meta.db_table),
', '.join(self.quote_name(x) for x in mapping),
', '.join(mapping.values()),
self.quote_name(model._meta.db_table),
))
# Delete the old table to make way for the new
self.delete_model(model, handle_autom2m=False)
# Rename the new table to take way for the old
self.alter_db_table(
new_model, new_model._meta.db_table, model._meta.db_table,
disable_constraints=False,
)
# Run deferred SQL on correct table
for sql in self.deferred_sql:
self.execute(sql)
self.deferred_sql = []
# Fix any PK-removed field
if restore_pk_field:
restore_pk_field.primary_key = True
def delete_model(self, model, handle_autom2m=True):
if handle_autom2m:
super().delete_model(model)
else:
# Delete the table (and only that)
self.execute(self.sql_delete_table % {
"table": self.quote_name(model._meta.db_table),
})
# Remove all deferred statements referencing the deleted table.
for sql in list(self.deferred_sql):
if isinstance(sql, Statement) and sql.references_table(model._meta.db_table):
self.deferred_sql.remove(sql)
def add_field(self, model, field):
"""Create a field on a model."""
if (
# Primary keys and unique fields are not supported in ALTER TABLE
# ADD COLUMN.
field.primary_key or field.unique or
# Fields with default values cannot by handled by ALTER TABLE ADD
# COLUMN statement because DROP DEFAULT is not supported in
# ALTER TABLE.
not field.null or self.effective_default(field) is not None
):
self._remake_table(model, create_field=field)
else:
super().add_field(model, field)
def remove_field(self, model, field):
"""
Remove a field from a model. Usually involves deleting a column,
but for M2Ms may involve deleting a table.
"""
# M2M fields are a special case
if field.many_to_many:
# For implicit M2M tables, delete the auto-created table
if field.remote_field.through._meta.auto_created:
self.delete_model(field.remote_field.through)
# For explicit "through" M2M fields, do nothing
# For everything else, remake.
else:
# It might not actually have a column behind it
if field.db_parameters(connection=self.connection)['type'] is None:
return
self._remake_table(model, delete_field=field)
def _alter_field(self, model, old_field, new_field, old_type, new_type,
old_db_params, new_db_params, strict=False):
"""Perform a "physical" (non-ManyToMany) field update."""
# Use "ALTER TABLE ... RENAME COLUMN" if only the column name
# changed and there aren't any constraints.
if (self.connection.features.can_alter_table_rename_column and
old_field.column != new_field.column and
self.column_sql(model, old_field) == self.column_sql(model, new_field) and
not (old_field.remote_field and old_field.db_constraint or
new_field.remote_field and new_field.db_constraint)):
return self.execute(self._rename_field_sql(model._meta.db_table, old_field, new_field, new_type))
# Alter by remaking table
self._remake_table(model, alter_field=(old_field, new_field))
# Rebuild tables with FKs pointing to this field.
if new_field.unique and old_type != new_type:
related_models = set()
opts = new_field.model._meta
for remote_field in opts.related_objects:
# Ignore self-relationship since the table was already rebuilt.
if remote_field.related_model == model:
continue
if not remote_field.many_to_many:
if remote_field.field_name == new_field.name:
related_models.add(remote_field.related_model)
elif new_field.primary_key and remote_field.through._meta.auto_created:
related_models.add(remote_field.through)
if new_field.primary_key:
for many_to_many in opts.many_to_many:
# Ignore self-relationship since the table was already rebuilt.
if many_to_many.related_model == model:
continue
if many_to_many.remote_field.through._meta.auto_created:
related_models.add(many_to_many.remote_field.through)
for related_model in related_models:
self._remake_table(related_model)
def _alter_many_to_many(self, model, old_field, new_field, strict):
"""Alter M2Ms to repoint their to= endpoints."""
if old_field.remote_field.through._meta.db_table == new_field.remote_field.through._meta.db_table:
# The field name didn't change, but some options did; we have to propagate this altering.
self._remake_table(
old_field.remote_field.through,
alter_field=(
# We need the field that points to the target model, so we can tell alter_field to change it -
# this is m2m_reverse_field_name() (as opposed to m2m_field_name, which points to our model)
old_field.remote_field.through._meta.get_field(old_field.m2m_reverse_field_name()),
new_field.remote_field.through._meta.get_field(new_field.m2m_reverse_field_name()),
),
)
return
# Make a new through table
self.create_model(new_field.remote_field.through)
# Copy the data across
self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
self.quote_name(new_field.remote_field.through._meta.db_table),
', '.join([
"id",
new_field.m2m_column_name(),
new_field.m2m_reverse_name(),
]),
', '.join([
"id",
old_field.m2m_column_name(),
old_field.m2m_reverse_name(),
]),
self.quote_name(old_field.remote_field.through._meta.db_table),
))
# Delete the old through table
self.delete_model(old_field.remote_field.through)
def add_constraint(self, model, constraint):
if isinstance(constraint, UniqueConstraint) and (
constraint.condition or
constraint.contains_expressions or
constraint.include or
constraint.deferrable
):
super().add_constraint(model, constraint)
else:
self._remake_table(model)
def remove_constraint(self, model, constraint):
if isinstance(constraint, UniqueConstraint) and (
constraint.condition or
constraint.contains_expressions or
constraint.include or
constraint.deferrable
):
super().remove_constraint(model, constraint)
else:
self._remake_table(model)
def _collate_sql(self, collation):
return 'COLLATE ' + collation
|
4796d82ed63ffdd34f3f83bfbab7213eb809563a7bc80bedd1c2aea1d6a68982 | """
Implementations of SQL functions for SQLite.
"""
import functools
import random
import statistics
from datetime import timedelta
from hashlib import sha1, sha224, sha256, sha384, sha512
from math import (
acos, asin, atan, atan2, ceil, cos, degrees, exp, floor, fmod, log, pi,
radians, sin, sqrt, tan,
)
from re import search as re_search
from django.db.backends.base.base import timezone_constructor
from django.db.backends.utils import (
split_tzname_delta, typecast_time, typecast_timestamp,
)
from django.utils import timezone
from django.utils.crypto import md5
from django.utils.duration import duration_microseconds
def register(connection):
create_deterministic_function = functools.partial(
connection.create_function,
deterministic=True,
)
create_deterministic_function('django_date_extract', 2, _sqlite_datetime_extract)
create_deterministic_function('django_date_trunc', 4, _sqlite_date_trunc)
create_deterministic_function('django_datetime_cast_date', 3, _sqlite_datetime_cast_date)
create_deterministic_function('django_datetime_cast_time', 3, _sqlite_datetime_cast_time)
create_deterministic_function('django_datetime_extract', 4, _sqlite_datetime_extract)
create_deterministic_function('django_datetime_trunc', 4, _sqlite_datetime_trunc)
create_deterministic_function('django_time_extract', 2, _sqlite_time_extract)
create_deterministic_function('django_time_trunc', 4, _sqlite_time_trunc)
create_deterministic_function('django_time_diff', 2, _sqlite_time_diff)
create_deterministic_function('django_timestamp_diff', 2, _sqlite_timestamp_diff)
create_deterministic_function('django_format_dtdelta', 3, _sqlite_format_dtdelta)
create_deterministic_function('regexp', 2, _sqlite_regexp)
create_deterministic_function('ACOS', 1, _sqlite_acos)
create_deterministic_function('ASIN', 1, _sqlite_asin)
create_deterministic_function('ATAN', 1, _sqlite_atan)
create_deterministic_function('ATAN2', 2, _sqlite_atan2)
create_deterministic_function('BITXOR', 2, _sqlite_bitxor)
create_deterministic_function('CEILING', 1, _sqlite_ceiling)
create_deterministic_function('COS', 1, _sqlite_cos)
create_deterministic_function('COT', 1, _sqlite_cot)
create_deterministic_function('DEGREES', 1, _sqlite_degrees)
create_deterministic_function('EXP', 1, _sqlite_exp)
create_deterministic_function('FLOOR', 1, _sqlite_floor)
create_deterministic_function('LN', 1, _sqlite_ln)
create_deterministic_function('LOG', 2, _sqlite_log)
create_deterministic_function('LPAD', 3, _sqlite_lpad)
create_deterministic_function('MD5', 1, _sqlite_md5)
create_deterministic_function('MOD', 2, _sqlite_mod)
create_deterministic_function('PI', 0, _sqlite_pi)
create_deterministic_function('POWER', 2, _sqlite_power)
create_deterministic_function('RADIANS', 1, _sqlite_radians)
create_deterministic_function('REPEAT', 2, _sqlite_repeat)
create_deterministic_function('REVERSE', 1, _sqlite_reverse)
create_deterministic_function('RPAD', 3, _sqlite_rpad)
create_deterministic_function('SHA1', 1, _sqlite_sha1)
create_deterministic_function('SHA224', 1, _sqlite_sha224)
create_deterministic_function('SHA256', 1, _sqlite_sha256)
create_deterministic_function('SHA384', 1, _sqlite_sha384)
create_deterministic_function('SHA512', 1, _sqlite_sha512)
create_deterministic_function('SIGN', 1, _sqlite_sign)
create_deterministic_function('SIN', 1, _sqlite_sin)
create_deterministic_function('SQRT', 1, _sqlite_sqrt)
create_deterministic_function('TAN', 1, _sqlite_tan)
# Don't use the built-in RANDOM() function because it returns a value
# in the range [-1 * 2^63, 2^63 - 1] instead of [0, 1).
connection.create_function('RAND', 0, random.random)
connection.create_aggregate('STDDEV_POP', 1, StdDevPop)
connection.create_aggregate('STDDEV_SAMP', 1, StdDevSamp)
connection.create_aggregate('VAR_POP', 1, VarPop)
connection.create_aggregate('VAR_SAMP', 1, VarSamp)
def _sqlite_datetime_parse(dt, tzname=None, conn_tzname=None):
if dt is None:
return None
try:
dt = typecast_timestamp(dt)
except (TypeError, ValueError):
return None
if conn_tzname:
dt = dt.replace(tzinfo=timezone_constructor(conn_tzname))
if tzname is not None and tzname != conn_tzname:
tzname, sign, offset = split_tzname_delta(tzname)
if offset:
hours, minutes = offset.split(':')
offset_delta = timedelta(hours=int(hours), minutes=int(minutes))
dt += offset_delta if sign == '+' else -offset_delta
dt = timezone.localtime(dt, timezone_constructor(tzname))
return dt
def _sqlite_date_trunc(lookup_type, dt, tzname, conn_tzname):
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
if dt is None:
return None
if lookup_type == 'year':
return f'{dt.year:04d}-01-01'
elif lookup_type == 'quarter':
month_in_quarter = dt.month - (dt.month - 1) % 3
return f'{dt.year:04d}-{month_in_quarter:02d}-01'
elif lookup_type == 'month':
return f'{dt.year:04d}-{dt.month:02d}-01'
elif lookup_type == 'week':
dt = dt - timedelta(days=dt.weekday())
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d}'
elif lookup_type == 'day':
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d}'
raise ValueError(f'Unsupported lookup type: {lookup_type!r}')
def _sqlite_time_trunc(lookup_type, dt, tzname, conn_tzname):
if dt is None:
return None
dt_parsed = _sqlite_datetime_parse(dt, tzname, conn_tzname)
if dt_parsed is None:
try:
dt = typecast_time(dt)
except (ValueError, TypeError):
return None
else:
dt = dt_parsed
if lookup_type == 'hour':
return f'{dt.hour:02d}:00:00'
elif lookup_type == 'minute':
return f'{dt.hour:02d}:{dt.minute:02d}:00'
elif lookup_type == 'second':
return f'{dt.hour:02d}:{dt.minute:02d}:{dt.second:02d}'
raise ValueError(f'Unsupported lookup type: {lookup_type!r}')
def _sqlite_datetime_cast_date(dt, tzname, conn_tzname):
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
if dt is None:
return None
return dt.date().isoformat()
def _sqlite_datetime_cast_time(dt, tzname, conn_tzname):
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
if dt is None:
return None
return dt.time().isoformat()
def _sqlite_datetime_extract(lookup_type, dt, tzname=None, conn_tzname=None):
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
if dt is None:
return None
if lookup_type == 'week_day':
return (dt.isoweekday() % 7) + 1
elif lookup_type == 'iso_week_day':
return dt.isoweekday()
elif lookup_type == 'week':
return dt.isocalendar()[1]
elif lookup_type == 'quarter':
return ceil(dt.month / 3)
elif lookup_type == 'iso_year':
return dt.isocalendar()[0]
else:
return getattr(dt, lookup_type)
def _sqlite_datetime_trunc(lookup_type, dt, tzname, conn_tzname):
dt = _sqlite_datetime_parse(dt, tzname, conn_tzname)
if dt is None:
return None
if lookup_type == 'year':
return f'{dt.year:04d}-01-01 00:00:00'
elif lookup_type == 'quarter':
month_in_quarter = dt.month - (dt.month - 1) % 3
return f'{dt.year:04d}-{month_in_quarter:02d}-01 00:00:00'
elif lookup_type == 'month':
return f'{dt.year:04d}-{dt.month:02d}-01 00:00:00'
elif lookup_type == 'week':
dt = dt - timedelta(days=dt.weekday())
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} 00:00:00'
elif lookup_type == 'day':
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} 00:00:00'
elif lookup_type == 'hour':
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} {dt.hour:02d}:00:00'
elif lookup_type == 'minute':
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} {dt.hour:02d}:{dt.minute:02d}:00'
elif lookup_type == 'second':
return f'{dt.year:04d}-{dt.month:02d}-{dt.day:02d} {dt.hour:02d}:{dt.minute:02d}:{dt.second:02d}'
raise ValueError(f'Unsupported lookup type: {lookup_type!r}')
def _sqlite_time_extract(lookup_type, dt):
if dt is None:
return None
try:
dt = typecast_time(dt)
except (ValueError, TypeError):
return None
return getattr(dt, lookup_type)
def _sqlite_prepare_dtdelta_param(conn, param):
if conn in ['+', '-']:
if isinstance(param, int):
return timedelta(0, 0, param)
else:
return typecast_timestamp(param)
return param
def _sqlite_format_dtdelta(connector, lhs, rhs):
"""
LHS and RHS can be either:
- An integer number of microseconds
- A string representing a datetime
- A scalar value, e.g. float
"""
if connector is None or lhs is None or rhs is None:
return None
connector = connector.strip()
try:
real_lhs = _sqlite_prepare_dtdelta_param(connector, lhs)
real_rhs = _sqlite_prepare_dtdelta_param(connector, rhs)
except (ValueError, TypeError):
return None
if connector == '+':
# typecast_timestamp() returns a date or a datetime without timezone.
# It will be formatted as "%Y-%m-%d" or "%Y-%m-%d %H:%M:%S[.%f]"
out = str(real_lhs + real_rhs)
elif connector == '-':
out = str(real_lhs - real_rhs)
elif connector == '*':
out = real_lhs * real_rhs
else:
out = real_lhs / real_rhs
return out
def _sqlite_time_diff(lhs, rhs):
if lhs is None or rhs is None:
return None
left = typecast_time(lhs)
right = typecast_time(rhs)
return (
(left.hour * 60 * 60 * 1000000) +
(left.minute * 60 * 1000000) +
(left.second * 1000000) +
(left.microsecond) -
(right.hour * 60 * 60 * 1000000) -
(right.minute * 60 * 1000000) -
(right.second * 1000000) -
(right.microsecond)
)
def _sqlite_timestamp_diff(lhs, rhs):
if lhs is None or rhs is None:
return None
left = typecast_timestamp(lhs)
right = typecast_timestamp(rhs)
return duration_microseconds(left - right)
def _sqlite_regexp(pattern, string):
if pattern is None or string is None:
return None
if not isinstance(string, str):
string = str(string)
return bool(re_search(pattern, string))
def _sqlite_acos(x):
if x is None:
return None
return acos(x)
def _sqlite_asin(x):
if x is None:
return None
return asin(x)
def _sqlite_atan(x):
if x is None:
return None
return atan(x)
def _sqlite_atan2(y, x):
if y is None or x is None:
return None
return atan2(y, x)
def _sqlite_bitxor(x, y):
if x is None or y is None:
return None
return x ^ y
def _sqlite_ceiling(x):
if x is None:
return None
return ceil(x)
def _sqlite_cos(x):
if x is None:
return None
return cos(x)
def _sqlite_cot(x):
if x is None:
return None
return 1 / tan(x)
def _sqlite_degrees(x):
if x is None:
return None
return degrees(x)
def _sqlite_exp(x):
if x is None:
return None
return exp(x)
def _sqlite_floor(x):
if x is None:
return None
return floor(x)
def _sqlite_ln(x):
if x is None:
return None
return log(x)
def _sqlite_log(base, x):
if base is None or x is None:
return None
# Arguments reversed to match SQL standard.
return log(x, base)
def _sqlite_lpad(text, length, fill_text):
if text is None or length is None or fill_text is None:
return None
delta = length - len(text)
if delta <= 0:
return text[:length]
return (fill_text * length)[:delta] + text
def _sqlite_md5(text):
if text is None:
return None
return md5(text.encode()).hexdigest()
def _sqlite_mod(x, y):
if x is None or y is None:
return None
return fmod(x, y)
def _sqlite_pi():
return pi
def _sqlite_power(x, y):
if x is None or y is None:
return None
return x ** y
def _sqlite_radians(x):
if x is None:
return None
return radians(x)
def _sqlite_repeat(text, count):
if text is None or count is None:
return None
return text * count
def _sqlite_reverse(text):
if text is None:
return None
return text[::-1]
def _sqlite_rpad(text, length, fill_text):
if text is None or length is None or fill_text is None:
return None
return (text + fill_text * length)[:length]
def _sqlite_sha1(text):
if text is None:
return None
return sha1(text.encode()).hexdigest()
def _sqlite_sha224(text):
if text is None:
return None
return sha224(text.encode()).hexdigest()
def _sqlite_sha256(text):
if text is None:
return None
return sha256(text.encode()).hexdigest()
def _sqlite_sha384(text):
if text is None:
return None
return sha384(text.encode()).hexdigest()
def _sqlite_sha512(text):
if text is None:
return None
return sha512(text.encode()).hexdigest()
def _sqlite_sign(x):
if x is None:
return None
return (x > 0) - (x < 0)
def _sqlite_sin(x):
if x is None:
return None
return sin(x)
def _sqlite_sqrt(x):
if x is None:
return None
return sqrt(x)
def _sqlite_tan(x):
if x is None:
return None
return tan(x)
class ListAggregate(list):
step = list.append
class StdDevPop(ListAggregate):
finalize = statistics.pstdev
class StdDevSamp(ListAggregate):
finalize = statistics.stdev
class VarPop(ListAggregate):
finalize = statistics.pvariance
class VarSamp(ListAggregate):
finalize = statistics.variance
|
d10064d63b76983bfeeb0ba0bce6e04a32d57be68c7de8eaba5b722cf45c7006 | """
Utility functions for handling images.
Requires Pillow as you might imagine.
"""
import struct
import zlib
from django.core.files import File
class ImageFile(File):
"""
A mixin for use alongside django.core.files.base.File, which provides
additional features for dealing with images.
"""
@property
def width(self):
return self._get_image_dimensions()[0]
@property
def height(self):
return self._get_image_dimensions()[1]
def _get_image_dimensions(self):
if not hasattr(self, '_dimensions_cache'):
close = self.closed
self.open()
self._dimensions_cache = get_image_dimensions(self, close=close)
return self._dimensions_cache
def get_image_dimensions(file_or_path, close=False):
"""
Return the (width, height) of an image, given an open file or a path. Set
'close' to True to close the file at the end if it is initially in an open
state.
"""
from PIL import ImageFile as PillowImageFile
p = PillowImageFile.Parser()
if hasattr(file_or_path, 'read'):
file = file_or_path
file_pos = file.tell()
file.seek(0)
else:
try:
file = open(file_or_path, 'rb')
except OSError:
return (None, None)
close = True
try:
# Most of the time Pillow only needs a small chunk to parse the image
# and get the dimensions, but with some TIFF files Pillow needs to
# parse the whole file.
chunk_size = 1024
while 1:
data = file.read(chunk_size)
if not data:
break
try:
p.feed(data)
except zlib.error as e:
# ignore zlib complaining on truncated stream, just feed more
# data to parser (ticket #19457).
if e.args[0].startswith("Error -5"):
pass
else:
raise
except struct.error:
# Ignore PIL failing on a too short buffer when reads return
# less bytes than expected. Skip and feed more data to the
# parser (ticket #24544).
pass
except RuntimeError:
# e.g. "RuntimeError: could not create decoder object" for
# WebP files. A different chunk_size may work.
pass
if p.image:
return p.image.size
chunk_size *= 2
return (None, None)
finally:
if close:
file.close()
else:
file.seek(file_pos)
|
a85a4ef25d9e5baf385cf93c70d4607192e11cc3fc09a012ab5520497e091c43 | import os
import pathlib
from datetime import datetime
from urllib.parse import urljoin
from django.conf import settings
from django.core.exceptions import SuspiciousFileOperation
from django.core.files import File, locks
from django.core.files.move import file_move_safe
from django.core.files.utils import validate_file_name
from django.core.signals import setting_changed
from django.utils import timezone
from django.utils._os import safe_join
from django.utils.crypto import get_random_string
from django.utils.deconstruct import deconstructible
from django.utils.encoding import filepath_to_uri
from django.utils.functional import LazyObject, cached_property
from django.utils.module_loading import import_string
from django.utils.text import get_valid_filename
__all__ = (
'Storage', 'FileSystemStorage', 'DefaultStorage', 'default_storage',
'get_storage_class',
)
class Storage:
"""
A base storage class, providing some default behaviors that all other
storage systems can inherit or override, as necessary.
"""
# The following methods represent a public interface to private methods.
# These shouldn't be overridden by subclasses unless absolutely necessary.
def open(self, name, mode='rb'):
"""Retrieve the specified file from storage."""
return self._open(name, mode)
def save(self, name, content, max_length=None):
"""
Save new content to the file specified by name. The content should be
a proper File object or any Python file-like object, ready to be read
from the beginning.
"""
# Get the proper name for the file, as it will actually be saved.
if name is None:
name = content.name
if not hasattr(content, 'chunks'):
content = File(content, name)
name = self.get_available_name(name, max_length=max_length)
name = self._save(name, content)
# Ensure that the name returned from the storage system is still valid.
validate_file_name(name, allow_relative_path=True)
return name
# These methods are part of the public API, with default implementations.
def get_valid_name(self, name):
"""
Return a filename, based on the provided filename, that's suitable for
use in the target storage system.
"""
return get_valid_filename(name)
def get_alternative_name(self, file_root, file_ext):
"""
Return an alternative filename, by adding an underscore and a random 7
character alphanumeric string (before the file extension, if one
exists) to the filename.
"""
return '%s_%s%s' % (file_root, get_random_string(7), file_ext)
def get_available_name(self, name, max_length=None):
"""
Return a filename that's free on the target storage system and
available for new content to be written to.
"""
name = str(name).replace('\\', '/')
dir_name, file_name = os.path.split(name)
if '..' in pathlib.PurePath(dir_name).parts:
raise SuspiciousFileOperation("Detected path traversal attempt in '%s'" % dir_name)
validate_file_name(file_name)
file_root, file_ext = os.path.splitext(file_name)
# If the filename already exists, generate an alternative filename
# until it doesn't exist.
# Truncate original name if required, so the new filename does not
# exceed the max_length.
while self.exists(name) or (max_length and len(name) > max_length):
# file_ext includes the dot.
name = os.path.join(dir_name, self.get_alternative_name(file_root, file_ext))
if max_length is None:
continue
# Truncate file_root if max_length exceeded.
truncation = len(name) - max_length
if truncation > 0:
file_root = file_root[:-truncation]
# Entire file_root was truncated in attempt to find an available filename.
if not file_root:
raise SuspiciousFileOperation(
'Storage can not find an available filename for "%s". '
'Please make sure that the corresponding file field '
'allows sufficient "max_length".' % name
)
name = os.path.join(dir_name, self.get_alternative_name(file_root, file_ext))
return name
def generate_filename(self, filename):
"""
Validate the filename by calling get_valid_name() and return a filename
to be passed to the save() method.
"""
filename = str(filename).replace('\\', '/')
# `filename` may include a path as returned by FileField.upload_to.
dirname, filename = os.path.split(filename)
if '..' in pathlib.PurePath(dirname).parts:
raise SuspiciousFileOperation("Detected path traversal attempt in '%s'" % dirname)
return os.path.normpath(os.path.join(dirname, self.get_valid_name(filename)))
def path(self, name):
"""
Return a local filesystem path where the file can be retrieved using
Python's built-in open() function. Storage systems that can't be
accessed using open() should *not* implement this method.
"""
raise NotImplementedError("This backend doesn't support absolute paths.")
# The following methods form the public API for storage systems, but with
# no default implementations. Subclasses must implement *all* of these.
def delete(self, name):
"""
Delete the specified file from the storage system.
"""
raise NotImplementedError('subclasses of Storage must provide a delete() method')
def exists(self, name):
"""
Return True if a file referenced by the given name already exists in the
storage system, or False if the name is available for a new file.
"""
raise NotImplementedError('subclasses of Storage must provide an exists() method')
def listdir(self, path):
"""
List the contents of the specified path. Return a 2-tuple of lists:
the first item being directories, the second item being files.
"""
raise NotImplementedError('subclasses of Storage must provide a listdir() method')
def size(self, name):
"""
Return the total size, in bytes, of the file specified by name.
"""
raise NotImplementedError('subclasses of Storage must provide a size() method')
def url(self, name):
"""
Return an absolute URL where the file's contents can be accessed
directly by a web browser.
"""
raise NotImplementedError('subclasses of Storage must provide a url() method')
def get_accessed_time(self, name):
"""
Return the last accessed time (as a datetime) of the file specified by
name. The datetime will be timezone-aware if USE_TZ=True.
"""
raise NotImplementedError('subclasses of Storage must provide a get_accessed_time() method')
def get_created_time(self, name):
"""
Return the creation time (as a datetime) of the file specified by name.
The datetime will be timezone-aware if USE_TZ=True.
"""
raise NotImplementedError('subclasses of Storage must provide a get_created_time() method')
def get_modified_time(self, name):
"""
Return the last modified time (as a datetime) of the file specified by
name. The datetime will be timezone-aware if USE_TZ=True.
"""
raise NotImplementedError('subclasses of Storage must provide a get_modified_time() method')
@deconstructible
class FileSystemStorage(Storage):
"""
Standard filesystem storage
"""
# The combination of O_CREAT and O_EXCL makes os.open() raise OSError if
# the file already exists before it's opened.
OS_OPEN_FLAGS = os.O_WRONLY | os.O_CREAT | os.O_EXCL | getattr(os, 'O_BINARY', 0)
def __init__(self, location=None, base_url=None, file_permissions_mode=None,
directory_permissions_mode=None):
self._location = location
self._base_url = base_url
self._file_permissions_mode = file_permissions_mode
self._directory_permissions_mode = directory_permissions_mode
setting_changed.connect(self._clear_cached_properties)
def _clear_cached_properties(self, setting, **kwargs):
"""Reset setting based property values."""
if setting == 'MEDIA_ROOT':
self.__dict__.pop('base_location', None)
self.__dict__.pop('location', None)
elif setting == 'MEDIA_URL':
self.__dict__.pop('base_url', None)
elif setting == 'FILE_UPLOAD_PERMISSIONS':
self.__dict__.pop('file_permissions_mode', None)
elif setting == 'FILE_UPLOAD_DIRECTORY_PERMISSIONS':
self.__dict__.pop('directory_permissions_mode', None)
def _value_or_setting(self, value, setting):
return setting if value is None else value
@cached_property
def base_location(self):
return self._value_or_setting(self._location, settings.MEDIA_ROOT)
@cached_property
def location(self):
return os.path.abspath(self.base_location)
@cached_property
def base_url(self):
if self._base_url is not None and not self._base_url.endswith('/'):
self._base_url += '/'
return self._value_or_setting(self._base_url, settings.MEDIA_URL)
@cached_property
def file_permissions_mode(self):
return self._value_or_setting(self._file_permissions_mode, settings.FILE_UPLOAD_PERMISSIONS)
@cached_property
def directory_permissions_mode(self):
return self._value_or_setting(self._directory_permissions_mode, settings.FILE_UPLOAD_DIRECTORY_PERMISSIONS)
def _open(self, name, mode='rb'):
return File(open(self.path(name), mode))
def _save(self, name, content):
full_path = self.path(name)
# Create any intermediate directories that do not exist.
directory = os.path.dirname(full_path)
try:
if self.directory_permissions_mode is not None:
# Set the umask because os.makedirs() doesn't apply the "mode"
# argument to intermediate-level directories.
old_umask = os.umask(0o777 & ~self.directory_permissions_mode)
try:
os.makedirs(directory, self.directory_permissions_mode, exist_ok=True)
finally:
os.umask(old_umask)
else:
os.makedirs(directory, exist_ok=True)
except FileExistsError:
raise FileExistsError('%s exists and is not a directory.' % directory)
# There's a potential race condition between get_available_name and
# saving the file; it's possible that two threads might return the
# same name, at which point all sorts of fun happens. So we need to
# try to create the file, but if it already exists we have to go back
# to get_available_name() and try again.
while True:
try:
# This file has a file path that we can move.
if hasattr(content, 'temporary_file_path'):
file_move_safe(content.temporary_file_path(), full_path)
# This is a normal uploadedfile that we can stream.
else:
# The current umask value is masked out by os.open!
fd = os.open(full_path, self.OS_OPEN_FLAGS, 0o666)
_file = None
try:
locks.lock(fd, locks.LOCK_EX)
for chunk in content.chunks():
if _file is None:
mode = 'wb' if isinstance(chunk, bytes) else 'wt'
_file = os.fdopen(fd, mode)
_file.write(chunk)
finally:
locks.unlock(fd)
if _file is not None:
_file.close()
else:
os.close(fd)
except FileExistsError:
# A new name is needed if the file exists.
name = self.get_available_name(name)
full_path = self.path(name)
else:
# OK, the file save worked. Break out of the loop.
break
if self.file_permissions_mode is not None:
os.chmod(full_path, self.file_permissions_mode)
# Ensure the saved path is always relative to the storage root.
name = os.path.relpath(full_path, self.location)
# Store filenames with forward slashes, even on Windows.
return str(name).replace('\\', '/')
def delete(self, name):
if not name:
raise ValueError('The name must be given to delete().')
name = self.path(name)
# If the file or directory exists, delete it from the filesystem.
try:
if os.path.isdir(name):
os.rmdir(name)
else:
os.remove(name)
except FileNotFoundError:
# FileNotFoundError is raised if the file or directory was removed
# concurrently.
pass
def exists(self, name):
return os.path.lexists(self.path(name))
def listdir(self, path):
path = self.path(path)
directories, files = [], []
with os.scandir(path) as entries:
for entry in entries:
if entry.is_dir():
directories.append(entry.name)
else:
files.append(entry.name)
return directories, files
def path(self, name):
return safe_join(self.location, name)
def size(self, name):
return os.path.getsize(self.path(name))
def url(self, name):
if self.base_url is None:
raise ValueError("This file is not accessible via a URL.")
url = filepath_to_uri(name)
if url is not None:
url = url.lstrip('/')
return urljoin(self.base_url, url)
def _datetime_from_timestamp(self, ts):
"""
If timezone support is enabled, make an aware datetime object in UTC;
otherwise make a naive one in the local timezone.
"""
tz = timezone.utc if settings.USE_TZ else None
return datetime.fromtimestamp(ts, tz=tz)
def get_accessed_time(self, name):
return self._datetime_from_timestamp(os.path.getatime(self.path(name)))
def get_created_time(self, name):
return self._datetime_from_timestamp(os.path.getctime(self.path(name)))
def get_modified_time(self, name):
return self._datetime_from_timestamp(os.path.getmtime(self.path(name)))
def get_storage_class(import_path=None):
return import_string(import_path or settings.DEFAULT_FILE_STORAGE)
class DefaultStorage(LazyObject):
def _setup(self):
self._wrapped = get_storage_class()()
default_storage = DefaultStorage()
|
9004d7e7823e07ec6cd318b4f1eb6a28d76447daf89ab0ae0480efcfb5de8602 | """
Portable file locking utilities.
Based partially on an example by Jonathan Feignberg in the Python
Cookbook [1] (licensed under the Python Software License) and a ctypes port by
Anatoly Techtonik for Roundup [2] (license [3]).
[1] https://code.activestate.com/recipes/65203/
[2] https://sourceforge.net/p/roundup/code/ci/default/tree/roundup/backends/portalocker.py
[3] https://sourceforge.net/p/roundup/code/ci/default/tree/COPYING.txt
Example Usage::
>>> from django.core.files import locks
>>> with open('./file', 'wb') as f:
... locks.lock(f, locks.LOCK_EX)
... f.write('Django')
"""
import os
__all__ = ('LOCK_EX', 'LOCK_SH', 'LOCK_NB', 'lock', 'unlock')
def _fd(f):
"""Get a filedescriptor from something which could be a file or an fd."""
return f.fileno() if hasattr(f, 'fileno') else f
if os.name == 'nt':
import msvcrt
from ctypes import (
POINTER, Structure, Union, byref, c_int64, c_ulong, c_void_p, sizeof,
windll,
)
from ctypes.wintypes import BOOL, DWORD, HANDLE
LOCK_SH = 0 # the default
LOCK_NB = 0x1 # LOCKFILE_FAIL_IMMEDIATELY
LOCK_EX = 0x2 # LOCKFILE_EXCLUSIVE_LOCK
# --- Adapted from the pyserial project ---
# detect size of ULONG_PTR
if sizeof(c_ulong) != sizeof(c_void_p):
ULONG_PTR = c_int64
else:
ULONG_PTR = c_ulong
PVOID = c_void_p
# --- Union inside Structure by stackoverflow:3480240 ---
class _OFFSET(Structure):
_fields_ = [
('Offset', DWORD),
('OffsetHigh', DWORD)]
class _OFFSET_UNION(Union):
_anonymous_ = ['_offset']
_fields_ = [
('_offset', _OFFSET),
('Pointer', PVOID)]
class OVERLAPPED(Structure):
_anonymous_ = ['_offset_union']
_fields_ = [
('Internal', ULONG_PTR),
('InternalHigh', ULONG_PTR),
('_offset_union', _OFFSET_UNION),
('hEvent', HANDLE)]
LPOVERLAPPED = POINTER(OVERLAPPED)
# --- Define function prototypes for extra safety ---
LockFileEx = windll.kernel32.LockFileEx
LockFileEx.restype = BOOL
LockFileEx.argtypes = [HANDLE, DWORD, DWORD, DWORD, DWORD, LPOVERLAPPED]
UnlockFileEx = windll.kernel32.UnlockFileEx
UnlockFileEx.restype = BOOL
UnlockFileEx.argtypes = [HANDLE, DWORD, DWORD, DWORD, LPOVERLAPPED]
def lock(f, flags):
hfile = msvcrt.get_osfhandle(_fd(f))
overlapped = OVERLAPPED()
ret = LockFileEx(hfile, flags, 0, 0, 0xFFFF0000, byref(overlapped))
return bool(ret)
def unlock(f):
hfile = msvcrt.get_osfhandle(_fd(f))
overlapped = OVERLAPPED()
ret = UnlockFileEx(hfile, 0, 0, 0xFFFF0000, byref(overlapped))
return bool(ret)
else:
try:
import fcntl
LOCK_SH = fcntl.LOCK_SH # shared lock
LOCK_NB = fcntl.LOCK_NB # non-blocking
LOCK_EX = fcntl.LOCK_EX
except (ImportError, AttributeError):
# File locking is not supported.
LOCK_EX = LOCK_SH = LOCK_NB = 0
# Dummy functions that don't do anything.
def lock(f, flags):
# File is not locked
return False
def unlock(f):
# File is unlocked
return True
else:
def lock(f, flags):
try:
fcntl.flock(_fd(f), flags)
return True
except BlockingIOError:
return False
def unlock(f):
fcntl.flock(_fd(f), fcntl.LOCK_UN)
return True
|
5da6f12bd5b1a4980892649d4e372c9eabb474604190c39b6bf1cb658fd57d2d | import copy
from collections import defaultdict
from django.conf import settings
from django.template.backends.django import get_template_tag_modules
from . import Error, Tags, register
E001 = Error(
"You have 'APP_DIRS': True in your TEMPLATES but also specify 'loaders' "
"in OPTIONS. Either remove APP_DIRS or remove the 'loaders' option.",
id='templates.E001',
)
E002 = Error(
"'string_if_invalid' in TEMPLATES OPTIONS must be a string but got: {} ({}).",
id="templates.E002",
)
E003 = Error(
'{} is used for multiple template tag modules: {}',
id='templates.E003',
)
@register(Tags.templates)
def check_setting_app_dirs_loaders(app_configs, **kwargs):
return [E001] if any(
conf.get('APP_DIRS') and 'loaders' in conf.get('OPTIONS', {})
for conf in settings.TEMPLATES
) else []
@register(Tags.templates)
def check_string_if_invalid_is_string(app_configs, **kwargs):
errors = []
for conf in settings.TEMPLATES:
string_if_invalid = conf.get('OPTIONS', {}).get('string_if_invalid', '')
if not isinstance(string_if_invalid, str):
error = copy.copy(E002)
error.msg = error.msg.format(string_if_invalid, type(string_if_invalid).__name__)
errors.append(error)
return errors
@register(Tags.templates)
def check_for_template_tags_with_the_same_name(app_configs, **kwargs):
errors = []
libraries = defaultdict(list)
for conf in settings.TEMPLATES:
custom_libraries = conf.get('OPTIONS', {}).get('libraries', {})
for module_name, module_path in custom_libraries.items():
libraries[module_name].append(module_path)
for module_name, module_path in get_template_tag_modules():
libraries[module_name].append(module_path)
for library_name, items in libraries.items():
if len(items) > 1:
errors.append(Error(
E003.msg.format(
repr(library_name),
', '.join(repr(item) for item in items),
),
id=E003.id,
))
return errors
|
c87a5c0ba25d0fa237968dd0dfd3dc8106ae9d6e6d451e938f7055b067501f67 | import functools
import os
import pkgutil
import sys
from argparse import (
_AppendConstAction, _CountAction, _StoreConstAction, _SubParsersAction,
)
from collections import defaultdict
from difflib import get_close_matches
from importlib import import_module
import django
from django.apps import apps
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.core.management.base import (
BaseCommand, CommandError, CommandParser, handle_default_options,
)
from django.core.management.color import color_style
from django.utils import autoreload
def find_commands(management_dir):
"""
Given a path to a management directory, return a list of all the command
names that are available.
"""
command_dir = os.path.join(management_dir, 'commands')
return [name for _, name, is_pkg in pkgutil.iter_modules([command_dir])
if not is_pkg and not name.startswith('_')]
def load_command_class(app_name, name):
"""
Given a command name and an application name, return the Command
class instance. Allow all errors raised by the import process
(ImportError, AttributeError) to propagate.
"""
module = import_module('%s.management.commands.%s' % (app_name, name))
return module.Command()
@functools.lru_cache(maxsize=None)
def get_commands():
"""
Return a dictionary mapping command names to their callback applications.
Look for a management.commands package in django.core, and in each
installed application -- if a commands package exists, register all
commands in that package.
Core commands are always included. If a settings module has been
specified, also include user-defined commands.
The dictionary is in the format {command_name: app_name}. Key-value
pairs from this dictionary can then be used in calls to
load_command_class(app_name, command_name)
If a specific version of a command must be loaded (e.g., with the
startapp command), the instantiated module can be placed in the
dictionary in place of the application name.
The dictionary is cached on the first call and reused on subsequent
calls.
"""
commands = {name: 'django.core' for name in find_commands(__path__[0])}
if not settings.configured:
return commands
for app_config in reversed(apps.get_app_configs()):
path = os.path.join(app_config.path, 'management')
commands.update({name: app_config.name for name in find_commands(path)})
return commands
def call_command(command_name, *args, **options):
"""
Call the given command, with the given options and args/kwargs.
This is the primary API you should use for calling specific commands.
`command_name` may be a string or a command object. Using a string is
preferred unless the command object is required for further processing or
testing.
Some examples:
call_command('migrate')
call_command('shell', plain=True)
call_command('sqlmigrate', 'myapp')
from django.core.management.commands import flush
cmd = flush.Command()
call_command(cmd, verbosity=0, interactive=False)
# Do something with cmd ...
"""
if isinstance(command_name, BaseCommand):
# Command object passed in.
command = command_name
command_name = command.__class__.__module__.split('.')[-1]
else:
# Load the command object by name.
try:
app_name = get_commands()[command_name]
except KeyError:
raise CommandError("Unknown command: %r" % command_name)
if isinstance(app_name, BaseCommand):
# If the command is already loaded, use it directly.
command = app_name
else:
command = load_command_class(app_name, command_name)
# Simulate argument parsing to get the option defaults (see #10080 for details).
parser = command.create_parser('', command_name)
# Use the `dest` option name from the parser option
opt_mapping = {
min(s_opt.option_strings).lstrip('-').replace('-', '_'): s_opt.dest
for s_opt in parser._actions if s_opt.option_strings
}
arg_options = {opt_mapping.get(key, key): value for key, value in options.items()}
parse_args = []
for arg in args:
if isinstance(arg, (list, tuple)):
parse_args += map(str, arg)
else:
parse_args.append(str(arg))
def get_actions(parser):
# Parser actions and actions from sub-parser choices.
for opt in parser._actions:
if isinstance(opt, _SubParsersAction):
for sub_opt in opt.choices.values():
yield from get_actions(sub_opt)
else:
yield opt
parser_actions = list(get_actions(parser))
mutually_exclusive_required_options = {
opt
for group in parser._mutually_exclusive_groups
for opt in group._group_actions if group.required
}
# Any required arguments which are passed in via **options must be passed
# to parse_args().
for opt in parser_actions:
if (
opt.dest in options and
(opt.required or opt in mutually_exclusive_required_options)
):
opt_dest_count = sum(v == opt.dest for v in opt_mapping.values())
if opt_dest_count > 1:
raise TypeError(
f'Cannot pass the dest {opt.dest!r} that matches multiple '
f'arguments via **options.'
)
parse_args.append(min(opt.option_strings))
if isinstance(opt, (_AppendConstAction, _CountAction, _StoreConstAction)):
continue
value = arg_options[opt.dest]
if isinstance(value, (list, tuple)):
parse_args += map(str, value)
else:
parse_args.append(str(value))
defaults = parser.parse_args(args=parse_args)
defaults = dict(defaults._get_kwargs(), **arg_options)
# Raise an error if any unknown options were passed.
stealth_options = set(command.base_stealth_options + command.stealth_options)
dest_parameters = {action.dest for action in parser_actions}
valid_options = (dest_parameters | stealth_options).union(opt_mapping)
unknown_options = set(options) - valid_options
if unknown_options:
raise TypeError(
"Unknown option(s) for %s command: %s. "
"Valid options are: %s." % (
command_name,
', '.join(sorted(unknown_options)),
', '.join(sorted(valid_options)),
)
)
# Move positional args out of options to mimic legacy optparse
args = defaults.pop('args', ())
if 'skip_checks' not in options:
defaults['skip_checks'] = True
return command.execute(*args, **defaults)
class ManagementUtility:
"""
Encapsulate the logic of the django-admin and manage.py utilities.
"""
def __init__(self, argv=None):
self.argv = argv or sys.argv[:]
self.prog_name = os.path.basename(self.argv[0])
if self.prog_name == '__main__.py':
self.prog_name = 'python -m django'
self.settings_exception = None
def main_help_text(self, commands_only=False):
"""Return the script's main help text, as a string."""
if commands_only:
usage = sorted(get_commands())
else:
usage = [
"",
"Type '%s help <subcommand>' for help on a specific subcommand." % self.prog_name,
"",
"Available subcommands:",
]
commands_dict = defaultdict(lambda: [])
for name, app in get_commands().items():
if app == 'django.core':
app = 'django'
else:
app = app.rpartition('.')[-1]
commands_dict[app].append(name)
style = color_style()
for app in sorted(commands_dict):
usage.append("")
usage.append(style.NOTICE("[%s]" % app))
for name in sorted(commands_dict[app]):
usage.append(" %s" % name)
# Output an extra note if settings are not properly configured
if self.settings_exception is not None:
usage.append(style.NOTICE(
"Note that only Django core commands are listed "
"as settings are not properly configured (error: %s)."
% self.settings_exception))
return '\n'.join(usage)
def fetch_command(self, subcommand):
"""
Try to fetch the given subcommand, printing a message with the
appropriate command called from the command line (usually
"django-admin" or "manage.py") if it can't be found.
"""
# Get commands outside of try block to prevent swallowing exceptions
commands = get_commands()
try:
app_name = commands[subcommand]
except KeyError:
if os.environ.get('DJANGO_SETTINGS_MODULE'):
# If `subcommand` is missing due to misconfigured settings, the
# following line will retrigger an ImproperlyConfigured exception
# (get_commands() swallows the original one) so the user is
# informed about it.
settings.INSTALLED_APPS
elif not settings.configured:
sys.stderr.write("No Django settings specified.\n")
possible_matches = get_close_matches(subcommand, commands)
sys.stderr.write('Unknown command: %r' % subcommand)
if possible_matches:
sys.stderr.write('. Did you mean %s?' % possible_matches[0])
sys.stderr.write("\nType '%s help' for usage.\n" % self.prog_name)
sys.exit(1)
if isinstance(app_name, BaseCommand):
# If the command is already loaded, use it directly.
klass = app_name
else:
klass = load_command_class(app_name, subcommand)
return klass
def autocomplete(self):
"""
Output completion suggestions for BASH.
The output of this function is passed to BASH's `COMREPLY` variable and
treated as completion suggestions. `COMREPLY` expects a space
separated string as the result.
The `COMP_WORDS` and `COMP_CWORD` BASH environment variables are used
to get information about the cli input. Please refer to the BASH
man-page for more information about this variables.
Subcommand options are saved as pairs. A pair consists of
the long option string (e.g. '--exclude') and a boolean
value indicating if the option requires arguments. When printing to
stdout, an equal sign is appended to options which require arguments.
Note: If debugging this function, it is recommended to write the debug
output in a separate file. Otherwise the debug output will be treated
and formatted as potential completion suggestions.
"""
# Don't complete if user hasn't sourced bash_completion file.
if 'DJANGO_AUTO_COMPLETE' not in os.environ:
return
cwords = os.environ['COMP_WORDS'].split()[1:]
cword = int(os.environ['COMP_CWORD'])
try:
curr = cwords[cword - 1]
except IndexError:
curr = ''
subcommands = [*get_commands(), 'help']
options = [('--help', False)]
# subcommand
if cword == 1:
print(' '.join(sorted(filter(lambda x: x.startswith(curr), subcommands))))
# subcommand options
# special case: the 'help' subcommand has no options
elif cwords[0] in subcommands and cwords[0] != 'help':
subcommand_cls = self.fetch_command(cwords[0])
# special case: add the names of installed apps to options
if cwords[0] in ('dumpdata', 'sqlmigrate', 'sqlsequencereset', 'test'):
try:
app_configs = apps.get_app_configs()
# Get the last part of the dotted path as the app name.
options.extend((app_config.label, 0) for app_config in app_configs)
except ImportError:
# Fail silently if DJANGO_SETTINGS_MODULE isn't set. The
# user will find out once they execute the command.
pass
parser = subcommand_cls.create_parser('', cwords[0])
options.extend(
(min(s_opt.option_strings), s_opt.nargs != 0)
for s_opt in parser._actions if s_opt.option_strings
)
# filter out previously specified options from available options
prev_opts = {x.split('=')[0] for x in cwords[1:cword - 1]}
options = (opt for opt in options if opt[0] not in prev_opts)
# filter options by current input
options = sorted((k, v) for k, v in options if k.startswith(curr))
for opt_label, require_arg in options:
# append '=' to options which require args
if require_arg:
opt_label += '='
print(opt_label)
# Exit code of the bash completion function is never passed back to
# the user, so it's safe to always exit with 0.
# For more details see #25420.
sys.exit(0)
def execute(self):
"""
Given the command-line arguments, figure out which subcommand is being
run, create a parser appropriate to that command, and run it.
"""
try:
subcommand = self.argv[1]
except IndexError:
subcommand = 'help' # Display help if no arguments were given.
# Preprocess options to extract --settings and --pythonpath.
# These options could affect the commands that are available, so they
# must be processed early.
parser = CommandParser(
prog=self.prog_name,
usage='%(prog)s subcommand [options] [args]',
add_help=False,
allow_abbrev=False,
)
parser.add_argument('--settings')
parser.add_argument('--pythonpath')
parser.add_argument('args', nargs='*') # catch-all
try:
options, args = parser.parse_known_args(self.argv[2:])
handle_default_options(options)
except CommandError:
pass # Ignore any option errors at this point.
try:
settings.INSTALLED_APPS
except ImproperlyConfigured as exc:
self.settings_exception = exc
except ImportError as exc:
self.settings_exception = exc
if settings.configured:
# Start the auto-reloading dev server even if the code is broken.
# The hardcoded condition is a code smell but we can't rely on a
# flag on the command class because we haven't located it yet.
if subcommand == 'runserver' and '--noreload' not in self.argv:
try:
autoreload.check_errors(django.setup)()
except Exception:
# The exception will be raised later in the child process
# started by the autoreloader. Pretend it didn't happen by
# loading an empty list of applications.
apps.all_models = defaultdict(dict)
apps.app_configs = {}
apps.apps_ready = apps.models_ready = apps.ready = True
# Remove options not compatible with the built-in runserver
# (e.g. options for the contrib.staticfiles' runserver).
# Changes here require manually testing as described in
# #27522.
_parser = self.fetch_command('runserver').create_parser('django', 'runserver')
_options, _args = _parser.parse_known_args(self.argv[2:])
for _arg in _args:
self.argv.remove(_arg)
# In all other cases, django.setup() is required to succeed.
else:
django.setup()
self.autocomplete()
if subcommand == 'help':
if '--commands' in args:
sys.stdout.write(self.main_help_text(commands_only=True) + '\n')
elif not options.args:
sys.stdout.write(self.main_help_text() + '\n')
else:
self.fetch_command(options.args[0]).print_help(self.prog_name, options.args[0])
# Special-cases: We want 'django-admin --version' and
# 'django-admin --help' to work, for backwards compatibility.
elif subcommand == 'version' or self.argv[1:] == ['--version']:
sys.stdout.write(django.get_version() + '\n')
elif self.argv[1:] in (['--help'], ['-h']):
sys.stdout.write(self.main_help_text() + '\n')
else:
self.fetch_command(subcommand).run_from_argv(self.argv)
def execute_from_command_line(argv=None):
"""Run a ManagementUtility."""
utility = ManagementUtility(argv)
utility.execute()
|
f03314d11e474df183bf5ec8d8ae5c415704e7002628e27e8184f6dfef44b47e | """
Base classes for writing management commands (named commands which can
be executed through ``django-admin`` or ``manage.py``).
"""
import argparse
import os
import sys
from argparse import ArgumentParser, HelpFormatter
from io import TextIOBase
import django
from django.core import checks
from django.core.exceptions import ImproperlyConfigured
from django.core.management.color import color_style, no_style
from django.db import DEFAULT_DB_ALIAS, connections
ALL_CHECKS = '__all__'
class CommandError(Exception):
"""
Exception class indicating a problem while executing a management
command.
If this exception is raised during the execution of a management
command, it will be caught and turned into a nicely-printed error
message to the appropriate output stream (i.e., stderr); as a
result, raising this exception (with a sensible description of the
error) is the preferred way to indicate that something has gone
wrong in the execution of a command.
"""
def __init__(self, *args, returncode=1, **kwargs):
self.returncode = returncode
super().__init__(*args, **kwargs)
class SystemCheckError(CommandError):
"""
The system check framework detected unrecoverable errors.
"""
pass
class CommandParser(ArgumentParser):
"""
Customized ArgumentParser class to improve some error messages and prevent
SystemExit in several occasions, as SystemExit is unacceptable when a
command is called programmatically.
"""
def __init__(self, *, missing_args_message=None, called_from_command_line=None, **kwargs):
self.missing_args_message = missing_args_message
self.called_from_command_line = called_from_command_line
super().__init__(**kwargs)
def parse_args(self, args=None, namespace=None):
# Catch missing argument for a better error message
if (self.missing_args_message and
not (args or any(not arg.startswith('-') for arg in args))):
self.error(self.missing_args_message)
return super().parse_args(args, namespace)
def error(self, message):
if self.called_from_command_line:
super().error(message)
else:
raise CommandError("Error: %s" % message)
def handle_default_options(options):
"""
Include any default options that all commands should accept here
so that ManagementUtility can handle them before searching for
user commands.
"""
if options.settings:
os.environ['DJANGO_SETTINGS_MODULE'] = options.settings
if options.pythonpath:
sys.path.insert(0, options.pythonpath)
def no_translations(handle_func):
"""Decorator that forces a command to run with translations deactivated."""
def wrapped(*args, **kwargs):
from django.utils import translation
saved_locale = translation.get_language()
translation.deactivate_all()
try:
res = handle_func(*args, **kwargs)
finally:
if saved_locale is not None:
translation.activate(saved_locale)
return res
return wrapped
class DjangoHelpFormatter(HelpFormatter):
"""
Customized formatter so that command-specific arguments appear in the
--help output before arguments common to all commands.
"""
show_last = {
'--version', '--verbosity', '--traceback', '--settings', '--pythonpath',
'--no-color', '--force-color', '--skip-checks',
}
def _reordered_actions(self, actions):
return sorted(
actions,
key=lambda a: set(a.option_strings) & self.show_last != set()
)
def add_usage(self, usage, actions, *args, **kwargs):
super().add_usage(usage, self._reordered_actions(actions), *args, **kwargs)
def add_arguments(self, actions):
super().add_arguments(self._reordered_actions(actions))
class OutputWrapper(TextIOBase):
"""
Wrapper around stdout/stderr
"""
@property
def style_func(self):
return self._style_func
@style_func.setter
def style_func(self, style_func):
if style_func and self.isatty():
self._style_func = style_func
else:
self._style_func = lambda x: x
def __init__(self, out, ending='\n'):
self._out = out
self.style_func = None
self.ending = ending
def __getattr__(self, name):
return getattr(self._out, name)
def flush(self):
if hasattr(self._out, 'flush'):
self._out.flush()
def isatty(self):
return hasattr(self._out, 'isatty') and self._out.isatty()
def write(self, msg='', style_func=None, ending=None):
ending = self.ending if ending is None else ending
if ending and not msg.endswith(ending):
msg += ending
style_func = style_func or self.style_func
self._out.write(style_func(msg))
class BaseCommand:
"""
The base class from which all management commands ultimately
derive.
Use this class if you want access to all of the mechanisms which
parse the command-line arguments and work out what code to call in
response; if you don't need to change any of that behavior,
consider using one of the subclasses defined in this file.
If you are interested in overriding/customizing various aspects of
the command-parsing and -execution behavior, the normal flow works
as follows:
1. ``django-admin`` or ``manage.py`` loads the command class
and calls its ``run_from_argv()`` method.
2. The ``run_from_argv()`` method calls ``create_parser()`` to get
an ``ArgumentParser`` for the arguments, parses them, performs
any environment changes requested by options like
``pythonpath``, and then calls the ``execute()`` method,
passing the parsed arguments.
3. The ``execute()`` method attempts to carry out the command by
calling the ``handle()`` method with the parsed arguments; any
output produced by ``handle()`` will be printed to standard
output and, if the command is intended to produce a block of
SQL statements, will be wrapped in ``BEGIN`` and ``COMMIT``.
4. If ``handle()`` or ``execute()`` raised any exception (e.g.
``CommandError``), ``run_from_argv()`` will instead print an error
message to ``stderr``.
Thus, the ``handle()`` method is typically the starting point for
subclasses; many built-in commands and command types either place
all of their logic in ``handle()``, or perform some additional
parsing work in ``handle()`` and then delegate from it to more
specialized methods as needed.
Several attributes affect behavior at various steps along the way:
``help``
A short description of the command, which will be printed in
help messages.
``output_transaction``
A boolean indicating whether the command outputs SQL
statements; if ``True``, the output will automatically be
wrapped with ``BEGIN;`` and ``COMMIT;``. Default value is
``False``.
``requires_migrations_checks``
A boolean; if ``True``, the command prints a warning if the set of
migrations on disk don't match the migrations in the database.
``requires_system_checks``
A list or tuple of tags, e.g. [Tags.staticfiles, Tags.models]. System
checks registered in the chosen tags will be checked for errors prior
to executing the command. The value '__all__' can be used to specify
that all system checks should be performed. Default value is '__all__'.
To validate an individual application's models
rather than all applications' models, call
``self.check(app_configs)`` from ``handle()``, where ``app_configs``
is the list of application's configuration provided by the
app registry.
``stealth_options``
A tuple of any options the command uses which aren't defined by the
argument parser.
"""
# Metadata about this command.
help = ''
# Configuration shortcuts that alter various logic.
_called_from_command_line = False
output_transaction = False # Whether to wrap the output in a "BEGIN; COMMIT;"
requires_migrations_checks = False
requires_system_checks = '__all__'
# Arguments, common to all commands, which aren't defined by the argument
# parser.
base_stealth_options = ('stderr', 'stdout')
# Command-specific options not defined by the argument parser.
stealth_options = ()
suppressed_base_arguments = set()
def __init__(self, stdout=None, stderr=None, no_color=False, force_color=False):
self.stdout = OutputWrapper(stdout or sys.stdout)
self.stderr = OutputWrapper(stderr or sys.stderr)
if no_color and force_color:
raise CommandError("'no_color' and 'force_color' can't be used together.")
if no_color:
self.style = no_style()
else:
self.style = color_style(force_color)
self.stderr.style_func = self.style.ERROR
if (
not isinstance(self.requires_system_checks, (list, tuple)) and
self.requires_system_checks != ALL_CHECKS
):
raise TypeError('requires_system_checks must be a list or tuple.')
def get_version(self):
"""
Return the Django version, which should be correct for all built-in
Django commands. User-supplied commands can override this method to
return their own version.
"""
return django.get_version()
def create_parser(self, prog_name, subcommand, **kwargs):
"""
Create and return the ``ArgumentParser`` which will be used to
parse the arguments to this command.
"""
parser = CommandParser(
prog='%s %s' % (os.path.basename(prog_name), subcommand),
description=self.help or None,
formatter_class=DjangoHelpFormatter,
missing_args_message=getattr(self, 'missing_args_message', None),
called_from_command_line=getattr(self, '_called_from_command_line', None),
**kwargs
)
self.add_base_argument(
parser, '--version', action='version', version=self.get_version(),
help="Show program's version number and exit.",
)
self.add_base_argument(
parser, '-v', '--verbosity', default=1,
type=int, choices=[0, 1, 2, 3],
help='Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, 3=very verbose output',
)
self.add_base_argument(
parser, '--settings',
help=(
'The Python path to a settings module, e.g. '
'"myproject.settings.main". If this isn\'t provided, the '
'DJANGO_SETTINGS_MODULE environment variable will be used.'
),
)
self.add_base_argument(
parser, '--pythonpath',
help='A directory to add to the Python path, e.g. "/home/djangoprojects/myproject".',
)
self.add_base_argument(
parser, '--traceback', action='store_true',
help='Raise on CommandError exceptions.',
)
self.add_base_argument(
parser, '--no-color', action='store_true',
help="Don't colorize the command output.",
)
self.add_base_argument(
parser, '--force-color', action='store_true',
help='Force colorization of the command output.',
)
if self.requires_system_checks:
parser.add_argument(
'--skip-checks', action='store_true',
help='Skip system checks.',
)
self.add_arguments(parser)
return parser
def add_arguments(self, parser):
"""
Entry point for subclassed commands to add custom arguments.
"""
pass
def add_base_argument(self, parser, *args, **kwargs):
"""
Call the parser's add_argument() method, suppressing the help text
according to BaseCommand.suppressed_base_arguments.
"""
for arg in args:
if arg in self.suppressed_base_arguments:
kwargs['help'] = argparse.SUPPRESS
break
parser.add_argument(*args, **kwargs)
def print_help(self, prog_name, subcommand):
"""
Print the help message for this command, derived from
``self.usage()``.
"""
parser = self.create_parser(prog_name, subcommand)
parser.print_help()
def run_from_argv(self, argv):
"""
Set up any environment changes requested (e.g., Python path
and Django settings), then run this command. If the
command raises a ``CommandError``, intercept it and print it sensibly
to stderr. If the ``--traceback`` option is present or the raised
``Exception`` is not ``CommandError``, raise it.
"""
self._called_from_command_line = True
parser = self.create_parser(argv[0], argv[1])
options = parser.parse_args(argv[2:])
cmd_options = vars(options)
# Move positional args out of options to mimic legacy optparse
args = cmd_options.pop('args', ())
handle_default_options(options)
try:
self.execute(*args, **cmd_options)
except CommandError as e:
if options.traceback:
raise
# SystemCheckError takes care of its own formatting.
if isinstance(e, SystemCheckError):
self.stderr.write(str(e), lambda x: x)
else:
self.stderr.write('%s: %s' % (e.__class__.__name__, e))
sys.exit(e.returncode)
finally:
try:
connections.close_all()
except ImproperlyConfigured:
# Ignore if connections aren't setup at this point (e.g. no
# configured settings).
pass
def execute(self, *args, **options):
"""
Try to execute this command, performing system checks if needed (as
controlled by the ``requires_system_checks`` attribute, except if
force-skipped).
"""
if options['force_color'] and options['no_color']:
raise CommandError("The --no-color and --force-color options can't be used together.")
if options['force_color']:
self.style = color_style(force_color=True)
elif options['no_color']:
self.style = no_style()
self.stderr.style_func = None
if options.get('stdout'):
self.stdout = OutputWrapper(options['stdout'])
if options.get('stderr'):
self.stderr = OutputWrapper(options['stderr'])
if self.requires_system_checks and not options['skip_checks']:
if self.requires_system_checks == ALL_CHECKS:
self.check()
else:
self.check(tags=self.requires_system_checks)
if self.requires_migrations_checks:
self.check_migrations()
output = self.handle(*args, **options)
if output:
if self.output_transaction:
connection = connections[options.get('database', DEFAULT_DB_ALIAS)]
output = '%s\n%s\n%s' % (
self.style.SQL_KEYWORD(connection.ops.start_transaction_sql()),
output,
self.style.SQL_KEYWORD(connection.ops.end_transaction_sql()),
)
self.stdout.write(output)
return output
def check(self, app_configs=None, tags=None, display_num_errors=False,
include_deployment_checks=False, fail_level=checks.ERROR,
databases=None):
"""
Use the system check framework to validate entire Django project.
Raise CommandError for any serious message (error or critical errors).
If there are only light messages (like warnings), print them to stderr
and don't raise an exception.
"""
all_issues = checks.run_checks(
app_configs=app_configs,
tags=tags,
include_deployment_checks=include_deployment_checks,
databases=databases,
)
header, body, footer = "", "", ""
visible_issue_count = 0 # excludes silenced warnings
if all_issues:
debugs = [e for e in all_issues if e.level < checks.INFO and not e.is_silenced()]
infos = [e for e in all_issues if checks.INFO <= e.level < checks.WARNING and not e.is_silenced()]
warnings = [e for e in all_issues if checks.WARNING <= e.level < checks.ERROR and not e.is_silenced()]
errors = [e for e in all_issues if checks.ERROR <= e.level < checks.CRITICAL and not e.is_silenced()]
criticals = [e for e in all_issues if checks.CRITICAL <= e.level and not e.is_silenced()]
sorted_issues = [
(criticals, 'CRITICALS'),
(errors, 'ERRORS'),
(warnings, 'WARNINGS'),
(infos, 'INFOS'),
(debugs, 'DEBUGS'),
]
for issues, group_name in sorted_issues:
if issues:
visible_issue_count += len(issues)
formatted = (
self.style.ERROR(str(e))
if e.is_serious()
else self.style.WARNING(str(e))
for e in issues)
formatted = "\n".join(sorted(formatted))
body += '\n%s:\n%s\n' % (group_name, formatted)
if visible_issue_count:
header = "System check identified some issues:\n"
if display_num_errors:
if visible_issue_count:
footer += '\n'
footer += "System check identified %s (%s silenced)." % (
"no issues" if visible_issue_count == 0 else
"1 issue" if visible_issue_count == 1 else
"%s issues" % visible_issue_count,
len(all_issues) - visible_issue_count,
)
if any(e.is_serious(fail_level) and not e.is_silenced() for e in all_issues):
msg = self.style.ERROR("SystemCheckError: %s" % header) + body + footer
raise SystemCheckError(msg)
else:
msg = header + body + footer
if msg:
if visible_issue_count:
self.stderr.write(msg, lambda x: x)
else:
self.stdout.write(msg)
def check_migrations(self):
"""
Print a warning if the set of migrations on disk don't match the
migrations in the database.
"""
from django.db.migrations.executor import MigrationExecutor
try:
executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
except ImproperlyConfigured:
# No databases are configured (or the dummy one)
return
plan = executor.migration_plan(executor.loader.graph.leaf_nodes())
if plan:
apps_waiting_migration = sorted({migration.app_label for migration, backwards in plan})
self.stdout.write(
self.style.NOTICE(
"\nYou have %(unapplied_migration_count)s unapplied migration(s). "
"Your project may not work properly until you apply the "
"migrations for app(s): %(apps_waiting_migration)s." % {
"unapplied_migration_count": len(plan),
"apps_waiting_migration": ", ".join(apps_waiting_migration),
}
)
)
self.stdout.write(self.style.NOTICE("Run 'python manage.py migrate' to apply them."))
def handle(self, *args, **options):
"""
The actual logic of the command. Subclasses must implement
this method.
"""
raise NotImplementedError('subclasses of BaseCommand must provide a handle() method')
class AppCommand(BaseCommand):
"""
A management command which takes one or more installed application labels
as arguments, and does something with each of them.
Rather than implementing ``handle()``, subclasses must implement
``handle_app_config()``, which will be called once for each application.
"""
missing_args_message = "Enter at least one application label."
def add_arguments(self, parser):
parser.add_argument('args', metavar='app_label', nargs='+', help='One or more application label.')
def handle(self, *app_labels, **options):
from django.apps import apps
try:
app_configs = [apps.get_app_config(app_label) for app_label in app_labels]
except (LookupError, ImportError) as e:
raise CommandError("%s. Are you sure your INSTALLED_APPS setting is correct?" % e)
output = []
for app_config in app_configs:
app_output = self.handle_app_config(app_config, **options)
if app_output:
output.append(app_output)
return '\n'.join(output)
def handle_app_config(self, app_config, **options):
"""
Perform the command's actions for app_config, an AppConfig instance
corresponding to an application label given on the command line.
"""
raise NotImplementedError(
"Subclasses of AppCommand must provide"
"a handle_app_config() method.")
class LabelCommand(BaseCommand):
"""
A management command which takes one or more arbitrary arguments
(labels) on the command line, and does something with each of
them.
Rather than implementing ``handle()``, subclasses must implement
``handle_label()``, which will be called once for each label.
If the arguments should be names of installed applications, use
``AppCommand`` instead.
"""
label = 'label'
missing_args_message = "Enter at least one %s." % label
def add_arguments(self, parser):
parser.add_argument('args', metavar=self.label, nargs='+')
def handle(self, *labels, **options):
output = []
for label in labels:
label_output = self.handle_label(label, **options)
if label_output:
output.append(label_output)
return '\n'.join(output)
def handle_label(self, label, **options):
"""
Perform the command's actions for ``label``, which will be the
string as given on the command line.
"""
raise NotImplementedError('subclasses of LabelCommand must provide a handle_label() method')
|
7ff76883682e9331f392cb92b17bf9d2278031b6a3de59658b2f065de3aeb82d | import fnmatch
import os
from pathlib import Path
from subprocess import run
from django.apps import apps as installed_apps
from django.utils.crypto import get_random_string
from django.utils.encoding import DEFAULT_LOCALE_ENCODING
from .base import CommandError, CommandParser
def popen_wrapper(args, stdout_encoding='utf-8'):
"""
Friendly wrapper around Popen.
Return stdout output, stderr output, and OS status code.
"""
try:
p = run(args, capture_output=True, close_fds=os.name != 'nt')
except OSError as err:
raise CommandError('Error executing %s' % args[0]) from err
return (
p.stdout.decode(stdout_encoding),
p.stderr.decode(DEFAULT_LOCALE_ENCODING, errors='replace'),
p.returncode
)
def handle_extensions(extensions):
"""
Organize multiple extensions that are separated with commas or passed by
using --extension/-e multiple times.
For example: running 'django-admin makemessages -e js,txt -e xhtml -a'
would result in an extension list: ['.js', '.txt', '.xhtml']
>>> handle_extensions(['.html', 'html,js,py,py,py,.py', 'py,.py'])
{'.html', '.js', '.py'}
>>> handle_extensions(['.html, txt,.tpl'])
{'.html', '.tpl', '.txt'}
"""
ext_list = []
for ext in extensions:
ext_list.extend(ext.replace(' ', '').split(','))
for i, ext in enumerate(ext_list):
if not ext.startswith('.'):
ext_list[i] = '.%s' % ext_list[i]
return set(ext_list)
def find_command(cmd, path=None, pathext=None):
if path is None:
path = os.environ.get('PATH', '').split(os.pathsep)
if isinstance(path, str):
path = [path]
# check if there are funny path extensions for executables, e.g. Windows
if pathext is None:
pathext = os.environ.get('PATHEXT', '.COM;.EXE;.BAT;.CMD').split(os.pathsep)
# don't use extensions if the command ends with one of them
for ext in pathext:
if cmd.endswith(ext):
pathext = ['']
break
# check if we find the command on PATH
for p in path:
f = os.path.join(p, cmd)
if os.path.isfile(f):
return f
for ext in pathext:
fext = f + ext
if os.path.isfile(fext):
return fext
return None
def get_random_secret_key():
"""
Return a 50 character random string usable as a SECRET_KEY setting value.
"""
chars = 'abcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*(-_=+)'
return get_random_string(50, chars)
def parse_apps_and_model_labels(labels):
"""
Parse a list of "app_label.ModelName" or "app_label" strings into actual
objects and return a two-element tuple:
(set of model classes, set of app_configs).
Raise a CommandError if some specified models or apps don't exist.
"""
apps = set()
models = set()
for label in labels:
if '.' in label:
try:
model = installed_apps.get_model(label)
except LookupError:
raise CommandError('Unknown model: %s' % label)
models.add(model)
else:
try:
app_config = installed_apps.get_app_config(label)
except LookupError as e:
raise CommandError(str(e))
apps.add(app_config)
return models, apps
def get_command_line_option(argv, option):
"""
Return the value of a command line option (which should include leading
dashes, e.g. '--testrunner') from an argument list. Return None if the
option wasn't passed or if the argument list couldn't be parsed.
"""
parser = CommandParser(add_help=False, allow_abbrev=False)
parser.add_argument(option, dest='value')
try:
options, _ = parser.parse_known_args(argv[2:])
except CommandError:
return None
else:
return options.value
def normalize_path_patterns(patterns):
"""Normalize an iterable of glob style patterns based on OS."""
patterns = [os.path.normcase(p) for p in patterns]
dir_suffixes = {'%s*' % path_sep for path_sep in {'/', os.sep}}
norm_patterns = []
for pattern in patterns:
for dir_suffix in dir_suffixes:
if pattern.endswith(dir_suffix):
norm_patterns.append(pattern[:-len(dir_suffix)])
break
else:
norm_patterns.append(pattern)
return norm_patterns
def is_ignored_path(path, ignore_patterns):
"""
Check if the given path should be ignored or not based on matching
one of the glob style `ignore_patterns`.
"""
path = Path(path)
def ignore(pattern):
return fnmatch.fnmatchcase(path.name, pattern) or fnmatch.fnmatchcase(str(path), pattern)
return any(ignore(pattern) for pattern in normalize_path_patterns(ignore_patterns))
|
4848bf8d6d412be13e9bb2d4148811abf0cd9614c0b31fdd0b9f464bd46ab12d | import argparse
import cgi
import mimetypes
import os
import posixpath
import shutil
import stat
import tempfile
from importlib import import_module
from urllib.request import build_opener
import django
from django.conf import settings
from django.core.management.base import BaseCommand, CommandError
from django.core.management.utils import handle_extensions
from django.template import Context, Engine
from django.utils import archive
from django.utils.version import get_docs_version
class TemplateCommand(BaseCommand):
"""
Copy either a Django application layout template or a Django project
layout template into the specified directory.
:param style: A color style object (see django.core.management.color).
:param app_or_project: The string 'app' or 'project'.
:param name: The name of the application or project.
:param directory: The directory to which the template should be copied.
:param options: The additional variables passed to project or app templates
"""
requires_system_checks = []
# The supported URL schemes
url_schemes = ['http', 'https', 'ftp']
# Rewrite the following suffixes when determining the target filename.
rewrite_template_suffixes = (
# Allow shipping invalid .py files without byte-compilation.
('.py-tpl', '.py'),
)
def add_arguments(self, parser):
parser.add_argument('name', help='Name of the application or project.')
parser.add_argument('directory', nargs='?', help='Optional destination directory')
parser.add_argument('--template', help='The path or URL to load the template from.')
parser.add_argument(
'--extension', '-e', dest='extensions',
action='append', default=['py'],
help='The file extension(s) to render (default: "py"). '
'Separate multiple extensions with commas, or use '
'-e multiple times.'
)
parser.add_argument(
'--name', '-n', dest='files',
action='append', default=[],
help='The file name(s) to render. Separate multiple file names '
'with commas, or use -n multiple times.'
)
parser.add_argument(
'--exclude', '-x',
action='append', default=argparse.SUPPRESS, nargs='?', const='',
help=(
'The directory name(s) to exclude, in addition to .git and '
'__pycache__. Can be used multiple times.'
),
)
def handle(self, app_or_project, name, target=None, **options):
self.app_or_project = app_or_project
self.a_or_an = 'an' if app_or_project == 'app' else 'a'
self.paths_to_remove = []
self.verbosity = options['verbosity']
self.validate_name(name)
# if some directory is given, make sure it's nicely expanded
if target is None:
top_dir = os.path.join(os.getcwd(), name)
try:
os.makedirs(top_dir)
except FileExistsError:
raise CommandError("'%s' already exists" % top_dir)
except OSError as e:
raise CommandError(e)
else:
top_dir = os.path.abspath(os.path.expanduser(target))
if app_or_project == 'app':
self.validate_name(os.path.basename(top_dir), 'directory')
if not os.path.exists(top_dir):
raise CommandError("Destination directory '%s' does not "
"exist, please create it first." % top_dir)
extensions = tuple(handle_extensions(options['extensions']))
extra_files = []
excluded_directories = ['.git', '__pycache__']
for file in options['files']:
extra_files.extend(map(lambda x: x.strip(), file.split(',')))
if exclude := options.get('exclude'):
for directory in exclude:
excluded_directories.append(directory.strip())
if self.verbosity >= 2:
self.stdout.write(
'Rendering %s template files with extensions: %s'
% (app_or_project, ', '.join(extensions))
)
self.stdout.write(
'Rendering %s template files with filenames: %s'
% (app_or_project, ', '.join(extra_files))
)
base_name = '%s_name' % app_or_project
base_subdir = '%s_template' % app_or_project
base_directory = '%s_directory' % app_or_project
camel_case_name = 'camel_case_%s_name' % app_or_project
camel_case_value = ''.join(x for x in name.title() if x != '_')
context = Context({
**options,
base_name: name,
base_directory: top_dir,
camel_case_name: camel_case_value,
'docs_version': get_docs_version(),
'django_version': django.__version__,
}, autoescape=False)
# Setup a stub settings environment for template rendering
if not settings.configured:
settings.configure()
django.setup()
template_dir = self.handle_template(options['template'],
base_subdir)
prefix_length = len(template_dir) + 1
for root, dirs, files in os.walk(template_dir):
path_rest = root[prefix_length:]
relative_dir = path_rest.replace(base_name, name)
if relative_dir:
target_dir = os.path.join(top_dir, relative_dir)
os.makedirs(target_dir, exist_ok=True)
for dirname in dirs[:]:
if 'exclude' not in options:
if dirname.startswith('.') or dirname == '__pycache__':
dirs.remove(dirname)
elif dirname in excluded_directories:
dirs.remove(dirname)
for filename in files:
if filename.endswith(('.pyo', '.pyc', '.py.class')):
# Ignore some files as they cause various breakages.
continue
old_path = os.path.join(root, filename)
new_path = os.path.join(
top_dir, relative_dir, filename.replace(base_name, name)
)
for old_suffix, new_suffix in self.rewrite_template_suffixes:
if new_path.endswith(old_suffix):
new_path = new_path[:-len(old_suffix)] + new_suffix
break # Only rewrite once
if os.path.exists(new_path):
raise CommandError(
"%s already exists. Overlaying %s %s into an existing "
"directory won't replace conflicting files." % (
new_path, self.a_or_an, app_or_project,
)
)
# Only render the Python files, as we don't want to
# accidentally render Django templates files
if new_path.endswith(extensions) or filename in extra_files:
with open(old_path, encoding='utf-8') as template_file:
content = template_file.read()
template = Engine().from_string(content)
content = template.render(context)
with open(new_path, 'w', encoding='utf-8') as new_file:
new_file.write(content)
else:
shutil.copyfile(old_path, new_path)
if self.verbosity >= 2:
self.stdout.write('Creating %s' % new_path)
try:
self.apply_umask(old_path, new_path)
self.make_writeable(new_path)
except OSError:
self.stderr.write(
"Notice: Couldn't set permission bits on %s. You're "
"probably using an uncommon filesystem setup. No "
"problem." % new_path, self.style.NOTICE)
if self.paths_to_remove:
if self.verbosity >= 2:
self.stdout.write('Cleaning up temporary files.')
for path_to_remove in self.paths_to_remove:
if os.path.isfile(path_to_remove):
os.remove(path_to_remove)
else:
shutil.rmtree(path_to_remove)
def handle_template(self, template, subdir):
"""
Determine where the app or project templates are.
Use django.__path__[0] as the default because the Django install
directory isn't known.
"""
if template is None:
return os.path.join(django.__path__[0], 'conf', subdir)
else:
if template.startswith('file://'):
template = template[7:]
expanded_template = os.path.expanduser(template)
expanded_template = os.path.normpath(expanded_template)
if os.path.isdir(expanded_template):
return expanded_template
if self.is_url(template):
# downloads the file and returns the path
absolute_path = self.download(template)
else:
absolute_path = os.path.abspath(expanded_template)
if os.path.exists(absolute_path):
return self.extract(absolute_path)
raise CommandError("couldn't handle %s template %s." %
(self.app_or_project, template))
def validate_name(self, name, name_or_dir='name'):
if name is None:
raise CommandError('you must provide {an} {app} name'.format(
an=self.a_or_an,
app=self.app_or_project,
))
# Check it's a valid directory name.
if not name.isidentifier():
raise CommandError(
"'{name}' is not a valid {app} {type}. Please make sure the "
"{type} is a valid identifier.".format(
name=name,
app=self.app_or_project,
type=name_or_dir,
)
)
# Check it cannot be imported.
try:
import_module(name)
except ImportError:
pass
else:
raise CommandError(
"'{name}' conflicts with the name of an existing Python "
"module and cannot be used as {an} {app} {type}. Please try "
"another {type}.".format(
name=name,
an=self.a_or_an,
app=self.app_or_project,
type=name_or_dir,
)
)
def download(self, url):
"""
Download the given URL and return the file name.
"""
def cleanup_url(url):
tmp = url.rstrip('/')
filename = tmp.split('/')[-1]
if url.endswith('/'):
display_url = tmp + '/'
else:
display_url = url
return filename, display_url
prefix = 'django_%s_template_' % self.app_or_project
tempdir = tempfile.mkdtemp(prefix=prefix, suffix='_download')
self.paths_to_remove.append(tempdir)
filename, display_url = cleanup_url(url)
if self.verbosity >= 2:
self.stdout.write('Downloading %s' % display_url)
the_path = os.path.join(tempdir, filename)
opener = build_opener()
opener.addheaders = [('User-Agent', f'Django/{django.__version__}')]
try:
with opener.open(url) as source, open(the_path, 'wb') as target:
headers = source.info()
target.write(source.read())
except OSError as e:
raise CommandError("couldn't download URL %s to %s: %s" %
(url, filename, e))
used_name = the_path.split('/')[-1]
# Trying to get better name from response headers
content_disposition = headers['content-disposition']
if content_disposition:
_, params = cgi.parse_header(content_disposition)
guessed_filename = params.get('filename') or used_name
else:
guessed_filename = used_name
# Falling back to content type guessing
ext = self.splitext(guessed_filename)[1]
content_type = headers['content-type']
if not ext and content_type:
ext = mimetypes.guess_extension(content_type)
if ext:
guessed_filename += ext
# Move the temporary file to a filename that has better
# chances of being recognized by the archive utils
if used_name != guessed_filename:
guessed_path = os.path.join(tempdir, guessed_filename)
shutil.move(the_path, guessed_path)
return guessed_path
# Giving up
return the_path
def splitext(self, the_path):
"""
Like os.path.splitext, but takes off .tar, too
"""
base, ext = posixpath.splitext(the_path)
if base.lower().endswith('.tar'):
ext = base[-4:] + ext
base = base[:-4]
return base, ext
def extract(self, filename):
"""
Extract the given file to a temporary directory and return
the path of the directory with the extracted content.
"""
prefix = 'django_%s_template_' % self.app_or_project
tempdir = tempfile.mkdtemp(prefix=prefix, suffix='_extract')
self.paths_to_remove.append(tempdir)
if self.verbosity >= 2:
self.stdout.write('Extracting %s' % filename)
try:
archive.extract(filename, tempdir)
return tempdir
except (archive.ArchiveException, OSError) as e:
raise CommandError("couldn't extract file %s to %s: %s" %
(filename, tempdir, e))
def is_url(self, template):
"""Return True if the name looks like a URL."""
if ':' not in template:
return False
scheme = template.split(':', 1)[0].lower()
return scheme in self.url_schemes
def apply_umask(self, old_path, new_path):
current_umask = os.umask(0)
os.umask(current_umask)
current_mode = stat.S_IMODE(os.stat(old_path).st_mode)
os.chmod(new_path, current_mode & ~current_umask)
def make_writeable(self, filename):
"""
Make sure that the file is writeable.
Useful if our source is read-only.
"""
if not os.access(filename, os.W_OK):
st = os.stat(filename)
new_permissions = stat.S_IMODE(st.st_mode) | stat.S_IWUSR
os.chmod(filename, new_permissions)
|
5adf6cfe23d8fdc76214df1fc74964e204daa2005fd9fd0bfa52fafc531df0bf | from django.utils.crypto import md5
TEMPLATE_FRAGMENT_KEY_TEMPLATE = 'template.cache.%s.%s'
def make_template_fragment_key(fragment_name, vary_on=None):
hasher = md5(usedforsecurity=False)
if vary_on is not None:
for arg in vary_on:
hasher.update(str(arg).encode())
hasher.update(b':')
return TEMPLATE_FRAGMENT_KEY_TEMPLATE % (fragment_name, hasher.hexdigest())
|
557b99859bf553a53ead971ab4996bba34e8ff5a599869018e045895dafd0833 | """
Module for abstract serializer/unserializer base classes.
"""
import pickle
import warnings
from io import StringIO
from django.core.exceptions import ObjectDoesNotExist
from django.db import models
from django.utils.deprecation import RemovedInDjango50Warning
DEFER_FIELD = object()
class PickleSerializer:
"""
Simple wrapper around pickle to be used in signing.dumps()/loads() and
cache backends.
"""
def __init__(self, protocol=None):
warnings.warn(
'PickleSerializer is deprecated due to its security risk. Use '
'JSONSerializer instead.',
RemovedInDjango50Warning,
)
self.protocol = pickle.HIGHEST_PROTOCOL if protocol is None else protocol
def dumps(self, obj):
return pickle.dumps(obj, self.protocol)
def loads(self, data):
return pickle.loads(data)
class SerializerDoesNotExist(KeyError):
"""The requested serializer was not found."""
pass
class SerializationError(Exception):
"""Something bad happened during serialization."""
pass
class DeserializationError(Exception):
"""Something bad happened during deserialization."""
@classmethod
def WithData(cls, original_exc, model, fk, field_value):
"""
Factory method for creating a deserialization error which has a more
explanatory message.
"""
return cls("%s: (%s:pk=%s) field_value was '%s'" % (original_exc, model, fk, field_value))
class M2MDeserializationError(Exception):
"""Something bad happened during deserialization of a ManyToManyField."""
def __init__(self, original_exc, pk):
self.original_exc = original_exc
self.pk = pk
class ProgressBar:
progress_width = 75
def __init__(self, output, total_count):
self.output = output
self.total_count = total_count
self.prev_done = 0
def update(self, count):
if not self.output:
return
perc = count * 100 // self.total_count
done = perc * self.progress_width // 100
if self.prev_done >= done:
return
self.prev_done = done
cr = '' if self.total_count == 1 else '\r'
self.output.write(cr + '[' + '.' * done + ' ' * (self.progress_width - done) + ']')
if done == self.progress_width:
self.output.write('\n')
self.output.flush()
class Serializer:
"""
Abstract serializer base class.
"""
# Indicates if the implemented serializer is only available for
# internal Django use.
internal_use_only = False
progress_class = ProgressBar
stream_class = StringIO
def serialize(self, queryset, *, stream=None, fields=None, use_natural_foreign_keys=False,
use_natural_primary_keys=False, progress_output=None, object_count=0, **options):
"""
Serialize a queryset.
"""
self.options = options
self.stream = stream if stream is not None else self.stream_class()
self.selected_fields = fields
self.use_natural_foreign_keys = use_natural_foreign_keys
self.use_natural_primary_keys = use_natural_primary_keys
progress_bar = self.progress_class(progress_output, object_count)
self.start_serialization()
self.first = True
for count, obj in enumerate(queryset, start=1):
self.start_object(obj)
# Use the concrete parent class' _meta instead of the object's _meta
# This is to avoid local_fields problems for proxy models. Refs #17717.
concrete_model = obj._meta.concrete_model
# When using natural primary keys, retrieve the pk field of the
# parent for multi-table inheritance child models. That field must
# be serialized, otherwise deserialization isn't possible.
if self.use_natural_primary_keys:
pk = concrete_model._meta.pk
pk_parent = pk if pk.remote_field and pk.remote_field.parent_link else None
else:
pk_parent = None
for field in concrete_model._meta.local_fields:
if field.serialize or field is pk_parent:
if field.remote_field is None:
if self.selected_fields is None or field.attname in self.selected_fields:
self.handle_field(obj, field)
else:
if self.selected_fields is None or field.attname[:-3] in self.selected_fields:
self.handle_fk_field(obj, field)
for field in concrete_model._meta.local_many_to_many:
if field.serialize:
if self.selected_fields is None or field.attname in self.selected_fields:
self.handle_m2m_field(obj, field)
self.end_object(obj)
progress_bar.update(count)
self.first = self.first and False
self.end_serialization()
return self.getvalue()
def start_serialization(self):
"""
Called when serializing of the queryset starts.
"""
raise NotImplementedError('subclasses of Serializer must provide a start_serialization() method')
def end_serialization(self):
"""
Called when serializing of the queryset ends.
"""
pass
def start_object(self, obj):
"""
Called when serializing of an object starts.
"""
raise NotImplementedError('subclasses of Serializer must provide a start_object() method')
def end_object(self, obj):
"""
Called when serializing of an object ends.
"""
pass
def handle_field(self, obj, field):
"""
Called to handle each individual (non-relational) field on an object.
"""
raise NotImplementedError('subclasses of Serializer must provide a handle_field() method')
def handle_fk_field(self, obj, field):
"""
Called to handle a ForeignKey field.
"""
raise NotImplementedError('subclasses of Serializer must provide a handle_fk_field() method')
def handle_m2m_field(self, obj, field):
"""
Called to handle a ManyToManyField.
"""
raise NotImplementedError('subclasses of Serializer must provide a handle_m2m_field() method')
def getvalue(self):
"""
Return the fully serialized queryset (or None if the output stream is
not seekable).
"""
if callable(getattr(self.stream, 'getvalue', None)):
return self.stream.getvalue()
class Deserializer:
"""
Abstract base deserializer class.
"""
def __init__(self, stream_or_string, **options):
"""
Init this serializer given a stream or a string
"""
self.options = options
if isinstance(stream_or_string, str):
self.stream = StringIO(stream_or_string)
else:
self.stream = stream_or_string
def __iter__(self):
return self
def __next__(self):
"""Iteration interface -- return the next item in the stream"""
raise NotImplementedError('subclasses of Deserializer must provide a __next__() method')
class DeserializedObject:
"""
A deserialized model.
Basically a container for holding the pre-saved deserialized data along
with the many-to-many data saved with the object.
Call ``save()`` to save the object (with the many-to-many data) to the
database; call ``save(save_m2m=False)`` to save just the object fields
(and not touch the many-to-many stuff.)
"""
def __init__(self, obj, m2m_data=None, deferred_fields=None):
self.object = obj
self.m2m_data = m2m_data
self.deferred_fields = deferred_fields
def __repr__(self):
return "<%s: %s(pk=%s)>" % (
self.__class__.__name__,
self.object._meta.label,
self.object.pk,
)
def save(self, save_m2m=True, using=None, **kwargs):
# Call save on the Model baseclass directly. This bypasses any
# model-defined save. The save is also forced to be raw.
# raw=True is passed to any pre/post_save signals.
models.Model.save_base(self.object, using=using, raw=True, **kwargs)
if self.m2m_data and save_m2m:
for accessor_name, object_list in self.m2m_data.items():
getattr(self.object, accessor_name).set(object_list)
# prevent a second (possibly accidental) call to save() from saving
# the m2m data twice.
self.m2m_data = None
def save_deferred_fields(self, using=None):
self.m2m_data = {}
for field, field_value in self.deferred_fields.items():
opts = self.object._meta
label = opts.app_label + '.' + opts.model_name
if isinstance(field.remote_field, models.ManyToManyRel):
try:
values = deserialize_m2m_values(field, field_value, using, handle_forward_references=False)
except M2MDeserializationError as e:
raise DeserializationError.WithData(e.original_exc, label, self.object.pk, e.pk)
self.m2m_data[field.name] = values
elif isinstance(field.remote_field, models.ManyToOneRel):
try:
value = deserialize_fk_value(field, field_value, using, handle_forward_references=False)
except Exception as e:
raise DeserializationError.WithData(e, label, self.object.pk, field_value)
setattr(self.object, field.attname, value)
self.save()
def build_instance(Model, data, db):
"""
Build a model instance.
If the model instance doesn't have a primary key and the model supports
natural keys, try to retrieve it from the database.
"""
default_manager = Model._meta.default_manager
pk = data.get(Model._meta.pk.attname)
if (pk is None and hasattr(default_manager, 'get_by_natural_key') and
hasattr(Model, 'natural_key')):
natural_key = Model(**data).natural_key()
try:
data[Model._meta.pk.attname] = Model._meta.pk.to_python(
default_manager.db_manager(db).get_by_natural_key(*natural_key).pk
)
except Model.DoesNotExist:
pass
return Model(**data)
def deserialize_m2m_values(field, field_value, using, handle_forward_references):
model = field.remote_field.model
if hasattr(model._default_manager, 'get_by_natural_key'):
def m2m_convert(value):
if hasattr(value, '__iter__') and not isinstance(value, str):
return model._default_manager.db_manager(using).get_by_natural_key(*value).pk
else:
return model._meta.pk.to_python(value)
else:
def m2m_convert(v):
return model._meta.pk.to_python(v)
try:
pks_iter = iter(field_value)
except TypeError as e:
raise M2MDeserializationError(e, field_value)
try:
values = []
for pk in pks_iter:
values.append(m2m_convert(pk))
return values
except Exception as e:
if isinstance(e, ObjectDoesNotExist) and handle_forward_references:
return DEFER_FIELD
else:
raise M2MDeserializationError(e, pk)
def deserialize_fk_value(field, field_value, using, handle_forward_references):
if field_value is None:
return None
model = field.remote_field.model
default_manager = model._default_manager
field_name = field.remote_field.field_name
if (hasattr(default_manager, 'get_by_natural_key') and
hasattr(field_value, '__iter__') and not isinstance(field_value, str)):
try:
obj = default_manager.db_manager(using).get_by_natural_key(*field_value)
except ObjectDoesNotExist:
if handle_forward_references:
return DEFER_FIELD
else:
raise
value = getattr(obj, field_name)
# If this is a natural foreign key to an object that has a FK/O2O as
# the foreign key, use the FK value.
if model._meta.pk.remote_field:
value = value.pk
return value
return model._meta.get_field(field_name).to_python(field_value)
|
d58cfcf8b39b0d0f6b09bb913864bc2cb24d2e028663441cf69c96363efe0107 | import logging
import sys
import tempfile
import traceback
from asgiref.sync import ThreadSensitiveContext, sync_to_async
from django.conf import settings
from django.core import signals
from django.core.exceptions import RequestAborted, RequestDataTooBig
from django.core.handlers import base
from django.http import (
FileResponse, HttpRequest, HttpResponse, HttpResponseBadRequest,
HttpResponseServerError, QueryDict, parse_cookie,
)
from django.urls import set_script_prefix
from django.utils.functional import cached_property
logger = logging.getLogger('django.request')
class ASGIRequest(HttpRequest):
"""
Custom request subclass that decodes from an ASGI-standard request dict
and wraps request body handling.
"""
# Number of seconds until a Request gives up on trying to read a request
# body and aborts.
body_receive_timeout = 60
def __init__(self, scope, body_file):
self.scope = scope
self._post_parse_error = False
self._read_started = False
self.resolver_match = None
self.script_name = self.scope.get('root_path', '')
if self.script_name and scope['path'].startswith(self.script_name):
# TODO: Better is-prefix checking, slash handling?
self.path_info = scope['path'][len(self.script_name):]
else:
self.path_info = scope['path']
# The Django path is different from ASGI scope path args, it should
# combine with script name.
if self.script_name:
self.path = '%s/%s' % (
self.script_name.rstrip('/'),
self.path_info.replace('/', '', 1),
)
else:
self.path = scope['path']
# HTTP basics.
self.method = self.scope['method'].upper()
# Ensure query string is encoded correctly.
query_string = self.scope.get('query_string', '')
if isinstance(query_string, bytes):
query_string = query_string.decode()
self.META = {
'REQUEST_METHOD': self.method,
'QUERY_STRING': query_string,
'SCRIPT_NAME': self.script_name,
'PATH_INFO': self.path_info,
# WSGI-expecting code will need these for a while
'wsgi.multithread': True,
'wsgi.multiprocess': True,
}
if self.scope.get('client'):
self.META['REMOTE_ADDR'] = self.scope['client'][0]
self.META['REMOTE_HOST'] = self.META['REMOTE_ADDR']
self.META['REMOTE_PORT'] = self.scope['client'][1]
if self.scope.get('server'):
self.META['SERVER_NAME'] = self.scope['server'][0]
self.META['SERVER_PORT'] = str(self.scope['server'][1])
else:
self.META['SERVER_NAME'] = 'unknown'
self.META['SERVER_PORT'] = '0'
# Headers go into META.
for name, value in self.scope.get('headers', []):
name = name.decode('latin1')
if name == 'content-length':
corrected_name = 'CONTENT_LENGTH'
elif name == 'content-type':
corrected_name = 'CONTENT_TYPE'
else:
corrected_name = 'HTTP_%s' % name.upper().replace('-', '_')
# HTTP/2 say only ASCII chars are allowed in headers, but decode
# latin1 just in case.
value = value.decode('latin1')
if corrected_name in self.META:
value = self.META[corrected_name] + ',' + value
self.META[corrected_name] = value
# Pull out request encoding, if provided.
self._set_content_type_params(self.META)
# Directly assign the body file to be our stream.
self._stream = body_file
# Other bits.
self.resolver_match = None
@cached_property
def GET(self):
return QueryDict(self.META['QUERY_STRING'])
def _get_scheme(self):
return self.scope.get('scheme') or super()._get_scheme()
def _get_post(self):
if not hasattr(self, '_post'):
self._load_post_and_files()
return self._post
def _set_post(self, post):
self._post = post
def _get_files(self):
if not hasattr(self, '_files'):
self._load_post_and_files()
return self._files
POST = property(_get_post, _set_post)
FILES = property(_get_files)
@cached_property
def COOKIES(self):
return parse_cookie(self.META.get('HTTP_COOKIE', ''))
class ASGIHandler(base.BaseHandler):
"""Handler for ASGI requests."""
request_class = ASGIRequest
# Size to chunk response bodies into for multiple response messages.
chunk_size = 2 ** 16
def __init__(self):
super().__init__()
self.load_middleware(is_async=True)
async def __call__(self, scope, receive, send):
"""
Async entrypoint - parses the request and hands off to get_response.
"""
# Serve only HTTP connections.
# FIXME: Allow to override this.
if scope['type'] != 'http':
raise ValueError(
'Django can only handle ASGI/HTTP connections, not %s.'
% scope['type']
)
async with ThreadSensitiveContext():
await self.handle(scope, receive, send)
async def handle(self, scope, receive, send):
"""
Handles the ASGI request. Called via the __call__ method.
"""
# Receive the HTTP request body as a stream object.
try:
body_file = await self.read_body(receive)
except RequestAborted:
return
# Request is complete and can be served.
set_script_prefix(self.get_script_prefix(scope))
await sync_to_async(signals.request_started.send, thread_sensitive=True)(sender=self.__class__, scope=scope)
# Get the request and check for basic issues.
request, error_response = self.create_request(scope, body_file)
if request is None:
await self.send_response(error_response, send)
return
# Get the response, using the async mode of BaseHandler.
response = await self.get_response_async(request)
response._handler_class = self.__class__
# Increase chunk size on file responses (ASGI servers handles low-level
# chunking).
if isinstance(response, FileResponse):
response.block_size = self.chunk_size
# Send the response.
await self.send_response(response, send)
async def read_body(self, receive):
"""Reads an HTTP body from an ASGI connection."""
# Use the tempfile that auto rolls-over to a disk file as it fills up.
body_file = tempfile.SpooledTemporaryFile(max_size=settings.FILE_UPLOAD_MAX_MEMORY_SIZE, mode='w+b')
while True:
message = await receive()
if message['type'] == 'http.disconnect':
# Early client disconnect.
raise RequestAborted()
# Add a body chunk from the message, if provided.
if 'body' in message:
body_file.write(message['body'])
# Quit out if that's the end.
if not message.get('more_body', False):
break
body_file.seek(0)
return body_file
def create_request(self, scope, body_file):
"""
Create the Request object and returns either (request, None) or
(None, response) if there is an error response.
"""
try:
return self.request_class(scope, body_file), None
except UnicodeDecodeError:
logger.warning(
'Bad Request (UnicodeDecodeError)',
exc_info=sys.exc_info(),
extra={'status_code': 400},
)
return None, HttpResponseBadRequest()
except RequestDataTooBig:
return None, HttpResponse('413 Payload too large', status=413)
def handle_uncaught_exception(self, request, resolver, exc_info):
"""Last-chance handler for exceptions."""
# There's no WSGI server to catch the exception further up
# if this fails, so translate it into a plain text response.
try:
return super().handle_uncaught_exception(request, resolver, exc_info)
except Exception:
return HttpResponseServerError(
traceback.format_exc() if settings.DEBUG else 'Internal Server Error',
content_type='text/plain',
)
async def send_response(self, response, send):
"""Encode and send a response out over ASGI."""
# Collect cookies into headers. Have to preserve header case as there
# are some non-RFC compliant clients that require e.g. Content-Type.
response_headers = []
for header, value in response.items():
if isinstance(header, str):
header = header.encode('ascii')
if isinstance(value, str):
value = value.encode('latin1')
response_headers.append((bytes(header), bytes(value)))
for c in response.cookies.values():
response_headers.append(
(b'Set-Cookie', c.output(header='').encode('ascii').strip())
)
# Initial response message.
await send({
'type': 'http.response.start',
'status': response.status_code,
'headers': response_headers,
})
# Streaming responses need to be pinned to their iterator.
if response.streaming:
# Access `__iter__` and not `streaming_content` directly in case
# it has been overridden in a subclass.
for part in response:
for chunk, _ in self.chunk_bytes(part):
await send({
'type': 'http.response.body',
'body': chunk,
# Ignore "more" as there may be more parts; instead,
# use an empty final closing message with False.
'more_body': True,
})
# Final closing message.
await send({'type': 'http.response.body'})
# Other responses just need chunking.
else:
# Yield chunks of response.
for chunk, last in self.chunk_bytes(response.content):
await send({
'type': 'http.response.body',
'body': chunk,
'more_body': not last,
})
await sync_to_async(response.close, thread_sensitive=True)()
@classmethod
def chunk_bytes(cls, data):
"""
Chunks some data up so it can be sent in reasonable size messages.
Yields (chunk, last_chunk) tuples.
"""
position = 0
if not data:
yield data, True
return
while position < len(data):
yield (
data[position:position + cls.chunk_size],
(position + cls.chunk_size) >= len(data),
)
position += cls.chunk_size
def get_script_prefix(self, scope):
"""
Return the script prefix to use from either the scope or a setting.
"""
if settings.FORCE_SCRIPT_NAME:
return settings.FORCE_SCRIPT_NAME
return scope.get('root_path', '') or ''
|
cfb771227664a69e4476e89be2ccb86b77ba123d8d1a1c320e9890cbd1f82597 | from io import BytesIO
from django.conf import settings
from django.core import signals
from django.core.handlers import base
from django.http import HttpRequest, QueryDict, parse_cookie
from django.urls import set_script_prefix
from django.utils.encoding import repercent_broken_unicode
from django.utils.functional import cached_property
from django.utils.regex_helper import _lazy_re_compile
_slashes_re = _lazy_re_compile(br'/+')
class LimitedStream:
"""Wrap another stream to disallow reading it past a number of bytes."""
def __init__(self, stream, limit):
self.stream = stream
self.remaining = limit
self.buffer = b''
def _read_limited(self, size=None):
if size is None or size > self.remaining:
size = self.remaining
if size == 0:
return b''
result = self.stream.read(size)
self.remaining -= len(result)
return result
def read(self, size=None):
if size is None:
result = self.buffer + self._read_limited()
self.buffer = b''
elif size < len(self.buffer):
result = self.buffer[:size]
self.buffer = self.buffer[size:]
else: # size >= len(self.buffer)
result = self.buffer + self._read_limited(size - len(self.buffer))
self.buffer = b''
return result
def readline(self, size=None):
while b'\n' not in self.buffer and \
(size is None or len(self.buffer) < size):
if size:
# since size is not None here, len(self.buffer) < size
chunk = self._read_limited(size - len(self.buffer))
else:
chunk = self._read_limited()
if not chunk:
break
self.buffer += chunk
sio = BytesIO(self.buffer)
if size:
line = sio.readline(size)
else:
line = sio.readline()
self.buffer = sio.read()
return line
class WSGIRequest(HttpRequest):
def __init__(self, environ):
script_name = get_script_name(environ)
# If PATH_INFO is empty (e.g. accessing the SCRIPT_NAME URL without a
# trailing slash), operate as if '/' was requested.
path_info = get_path_info(environ) or '/'
self.environ = environ
self.path_info = path_info
# be careful to only replace the first slash in the path because of
# http://test/something and http://test//something being different as
# stated in https://www.ietf.org/rfc/rfc2396.txt
self.path = '%s/%s' % (script_name.rstrip('/'),
path_info.replace('/', '', 1))
self.META = environ
self.META['PATH_INFO'] = path_info
self.META['SCRIPT_NAME'] = script_name
self.method = environ['REQUEST_METHOD'].upper()
# Set content_type, content_params, and encoding.
self._set_content_type_params(environ)
try:
content_length = int(environ.get('CONTENT_LENGTH'))
except (ValueError, TypeError):
content_length = 0
self._stream = LimitedStream(self.environ['wsgi.input'], content_length)
self._read_started = False
self.resolver_match = None
def _get_scheme(self):
return self.environ.get('wsgi.url_scheme')
@cached_property
def GET(self):
# The WSGI spec says 'QUERY_STRING' may be absent.
raw_query_string = get_bytes_from_wsgi(self.environ, 'QUERY_STRING', '')
return QueryDict(raw_query_string, encoding=self._encoding)
def _get_post(self):
if not hasattr(self, '_post'):
self._load_post_and_files()
return self._post
def _set_post(self, post):
self._post = post
@cached_property
def COOKIES(self):
raw_cookie = get_str_from_wsgi(self.environ, 'HTTP_COOKIE', '')
return parse_cookie(raw_cookie)
@property
def FILES(self):
if not hasattr(self, '_files'):
self._load_post_and_files()
return self._files
POST = property(_get_post, _set_post)
class WSGIHandler(base.BaseHandler):
request_class = WSGIRequest
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.load_middleware()
def __call__(self, environ, start_response):
set_script_prefix(get_script_name(environ))
signals.request_started.send(sender=self.__class__, environ=environ)
request = self.request_class(environ)
response = self.get_response(request)
response._handler_class = self.__class__
status = '%d %s' % (response.status_code, response.reason_phrase)
response_headers = [
*response.items(),
*(('Set-Cookie', c.output(header='')) for c in response.cookies.values()),
]
start_response(status, response_headers)
if getattr(response, 'file_to_stream', None) is not None and environ.get('wsgi.file_wrapper'):
# If `wsgi.file_wrapper` is used the WSGI server does not call
# .close on the response, but on the file wrapper. Patch it to use
# response.close instead which takes care of closing all files.
response.file_to_stream.close = response.close
response = environ['wsgi.file_wrapper'](response.file_to_stream, response.block_size)
return response
def get_path_info(environ):
"""Return the HTTP request's PATH_INFO as a string."""
path_info = get_bytes_from_wsgi(environ, 'PATH_INFO', '/')
return repercent_broken_unicode(path_info).decode()
def get_script_name(environ):
"""
Return the equivalent of the HTTP request's SCRIPT_NAME environment
variable. If Apache mod_rewrite is used, return what would have been
the script name prior to any rewriting (so it's the script name as seen
from the client's perspective), unless the FORCE_SCRIPT_NAME setting is
set (to anything).
"""
if settings.FORCE_SCRIPT_NAME is not None:
return settings.FORCE_SCRIPT_NAME
# If Apache's mod_rewrite had a whack at the URL, Apache set either
# SCRIPT_URL or REDIRECT_URL to the full resource URL before applying any
# rewrites. Unfortunately not every web server (lighttpd!) passes this
# information through all the time, so FORCE_SCRIPT_NAME, above, is still
# needed.
script_url = get_bytes_from_wsgi(environ, 'SCRIPT_URL', '') or get_bytes_from_wsgi(environ, 'REDIRECT_URL', '')
if script_url:
if b'//' in script_url:
# mod_wsgi squashes multiple successive slashes in PATH_INFO,
# do the same with script_url before manipulating paths (#17133).
script_url = _slashes_re.sub(b'/', script_url)
path_info = get_bytes_from_wsgi(environ, 'PATH_INFO', '')
script_name = script_url[:-len(path_info)] if path_info else script_url
else:
script_name = get_bytes_from_wsgi(environ, 'SCRIPT_NAME', '')
return script_name.decode()
def get_bytes_from_wsgi(environ, key, default):
"""
Get a value from the WSGI environ dictionary as bytes.
key and default should be strings.
"""
value = environ.get(key, default)
# Non-ASCII values in the WSGI environ are arbitrarily decoded with
# ISO-8859-1. This is wrong for Django websites where UTF-8 is the default.
# Re-encode to recover the original bytestring.
return value.encode('iso-8859-1')
def get_str_from_wsgi(environ, key, default):
"""
Get a value from the WSGI environ dictionary as str.
key and default should be str objects.
"""
value = get_bytes_from_wsgi(environ, key, default)
return value.decode(errors='replace')
|
6a6bb38ed814349575ef0041e52fca630bbb6da22ef1e2ff14d3ee010451350e | import asyncio
import logging
import sys
from functools import wraps
from asgiref.sync import sync_to_async
from django.conf import settings
from django.core import signals
from django.core.exceptions import (
BadRequest, PermissionDenied, RequestDataTooBig, SuspiciousOperation,
TooManyFieldsSent,
)
from django.http import Http404
from django.http.multipartparser import MultiPartParserError
from django.urls import get_resolver, get_urlconf
from django.utils.log import log_response
from django.views import debug
def convert_exception_to_response(get_response):
"""
Wrap the given get_response callable in exception-to-response conversion.
All exceptions will be converted. All known 4xx exceptions (Http404,
PermissionDenied, MultiPartParserError, SuspiciousOperation) will be
converted to the appropriate response, and all other exceptions will be
converted to 500 responses.
This decorator is automatically applied to all middleware to ensure that
no middleware leaks an exception and that the next middleware in the stack
can rely on getting a response instead of an exception.
"""
if asyncio.iscoroutinefunction(get_response):
@wraps(get_response)
async def inner(request):
try:
response = await get_response(request)
except Exception as exc:
response = await sync_to_async(response_for_exception, thread_sensitive=False)(request, exc)
return response
return inner
else:
@wraps(get_response)
def inner(request):
try:
response = get_response(request)
except Exception as exc:
response = response_for_exception(request, exc)
return response
return inner
def response_for_exception(request, exc):
if isinstance(exc, Http404):
if settings.DEBUG:
response = debug.technical_404_response(request, exc)
else:
response = get_exception_response(request, get_resolver(get_urlconf()), 404, exc)
elif isinstance(exc, PermissionDenied):
response = get_exception_response(request, get_resolver(get_urlconf()), 403, exc)
log_response(
'Forbidden (Permission denied): %s', request.path,
response=response,
request=request,
exception=exc,
)
elif isinstance(exc, MultiPartParserError):
response = get_exception_response(request, get_resolver(get_urlconf()), 400, exc)
log_response(
'Bad request (Unable to parse request body): %s', request.path,
response=response,
request=request,
exception=exc,
)
elif isinstance(exc, BadRequest):
if settings.DEBUG:
response = debug.technical_500_response(request, *sys.exc_info(), status_code=400)
else:
response = get_exception_response(request, get_resolver(get_urlconf()), 400, exc)
log_response(
'%s: %s', str(exc), request.path,
response=response,
request=request,
exception=exc,
)
elif isinstance(exc, SuspiciousOperation):
if isinstance(exc, (RequestDataTooBig, TooManyFieldsSent)):
# POST data can't be accessed again, otherwise the original
# exception would be raised.
request._mark_post_parse_error()
# The request logger receives events for any problematic request
# The security logger receives events for all SuspiciousOperations
security_logger = logging.getLogger('django.security.%s' % exc.__class__.__name__)
security_logger.error(
str(exc),
exc_info=exc,
extra={'status_code': 400, 'request': request},
)
if settings.DEBUG:
response = debug.technical_500_response(request, *sys.exc_info(), status_code=400)
else:
response = get_exception_response(request, get_resolver(get_urlconf()), 400, exc)
else:
signals.got_request_exception.send(sender=None, request=request)
response = handle_uncaught_exception(request, get_resolver(get_urlconf()), sys.exc_info())
log_response(
'%s: %s', response.reason_phrase, request.path,
response=response,
request=request,
exception=exc,
)
# Force a TemplateResponse to be rendered.
if not getattr(response, 'is_rendered', True) and callable(getattr(response, 'render', None)):
response = response.render()
return response
def get_exception_response(request, resolver, status_code, exception):
try:
callback = resolver.resolve_error_handler(status_code)
response = callback(request, exception=exception)
except Exception:
signals.got_request_exception.send(sender=None, request=request)
response = handle_uncaught_exception(request, resolver, sys.exc_info())
return response
def handle_uncaught_exception(request, resolver, exc_info):
"""
Processing for any otherwise uncaught exceptions (those that will
generate HTTP 500 responses).
"""
if settings.DEBUG_PROPAGATE_EXCEPTIONS:
raise
if settings.DEBUG:
return debug.technical_500_response(request, *exc_info)
# Return an HttpResponse that displays a friendly error message.
callback = resolver.resolve_error_handler(500)
return callback(request)
|
d7c40b6b2ade98c93837996de0e2c8f13f98e6af36c93724b262a803af137ca7 | import sys
import time
from importlib import import_module
from django.apps import apps
from django.core.management.base import (
BaseCommand, CommandError, no_translations,
)
from django.core.management.sql import (
emit_post_migrate_signal, emit_pre_migrate_signal,
)
from django.db import DEFAULT_DB_ALIAS, connections, router
from django.db.migrations.autodetector import MigrationAutodetector
from django.db.migrations.executor import MigrationExecutor
from django.db.migrations.loader import AmbiguityError
from django.db.migrations.state import ModelState, ProjectState
from django.utils.module_loading import module_has_submodule
from django.utils.text import Truncator
class Command(BaseCommand):
help = "Updates database schema. Manages both apps with migrations and those without."
requires_system_checks = []
def add_arguments(self, parser):
parser.add_argument(
'--skip-checks', action='store_true',
help='Skip system checks.',
)
parser.add_argument(
'app_label', nargs='?',
help='App label of an application to synchronize the state.',
)
parser.add_argument(
'migration_name', nargs='?',
help='Database state will be brought to the state after that '
'migration. Use the name "zero" to unapply all migrations.',
)
parser.add_argument(
'--noinput', '--no-input', action='store_false', dest='interactive',
help='Tells Django to NOT prompt the user for input of any kind.',
)
parser.add_argument(
'--database',
default=DEFAULT_DB_ALIAS,
help='Nominates a database to synchronize. Defaults to the "default" database.',
)
parser.add_argument(
'--fake', action='store_true',
help='Mark migrations as run without actually running them.',
)
parser.add_argument(
'--fake-initial', action='store_true',
help='Detect if tables already exist and fake-apply initial migrations if so. Make sure '
'that the current database schema matches your initial migration before using this '
'flag. Django will only check for an existing table name.',
)
parser.add_argument(
'--plan', action='store_true',
help='Shows a list of the migration actions that will be performed.',
)
parser.add_argument(
'--run-syncdb', action='store_true',
help='Creates tables for apps without migrations.',
)
parser.add_argument(
'--check', action='store_true', dest='check_unapplied',
help='Exits with a non-zero status if unapplied migrations exist.',
)
parser.add_argument(
'--prune', action='store_true', dest='prune',
help='Delete nonexistent migrations from the django_migrations table.',
)
@no_translations
def handle(self, *args, **options):
database = options['database']
if not options['skip_checks']:
self.check(databases=[database])
self.verbosity = options['verbosity']
self.interactive = options['interactive']
# Import the 'management' module within each installed app, to register
# dispatcher events.
for app_config in apps.get_app_configs():
if module_has_submodule(app_config.module, "management"):
import_module('.management', app_config.name)
# Get the database we're operating from
connection = connections[database]
# Hook for backends needing any database preparation
connection.prepare_database()
# Work out which apps have migrations and which do not
executor = MigrationExecutor(connection, self.migration_progress_callback)
# Raise an error if any migrations are applied before their dependencies.
executor.loader.check_consistent_history(connection)
# Before anything else, see if there's conflicting apps and drop out
# hard if there are any
conflicts = executor.loader.detect_conflicts()
if conflicts:
name_str = "; ".join(
"%s in %s" % (", ".join(names), app)
for app, names in conflicts.items()
)
raise CommandError(
"Conflicting migrations detected; multiple leaf nodes in the "
"migration graph: (%s).\nTo fix them run "
"'python manage.py makemigrations --merge'" % name_str
)
# If they supplied command line arguments, work out what they mean.
run_syncdb = options['run_syncdb']
target_app_labels_only = True
if options['app_label']:
# Validate app_label.
app_label = options['app_label']
try:
apps.get_app_config(app_label)
except LookupError as err:
raise CommandError(str(err))
if run_syncdb:
if app_label in executor.loader.migrated_apps:
raise CommandError("Can't use run_syncdb with app '%s' as it has migrations." % app_label)
elif app_label not in executor.loader.migrated_apps:
raise CommandError("App '%s' does not have migrations." % app_label)
if options['app_label'] and options['migration_name']:
migration_name = options['migration_name']
if migration_name == "zero":
targets = [(app_label, None)]
else:
try:
migration = executor.loader.get_migration_by_prefix(app_label, migration_name)
except AmbiguityError:
raise CommandError(
"More than one migration matches '%s' in app '%s'. "
"Please be more specific." %
(migration_name, app_label)
)
except KeyError:
raise CommandError("Cannot find a migration matching '%s' from app '%s'." % (
migration_name, app_label))
target = (app_label, migration.name)
# Partially applied squashed migrations are not included in the
# graph, use the last replacement instead.
if (
target not in executor.loader.graph.nodes and
target in executor.loader.replacements
):
incomplete_migration = executor.loader.replacements[target]
target = incomplete_migration.replaces[-1]
targets = [target]
target_app_labels_only = False
elif options['app_label']:
targets = [key for key in executor.loader.graph.leaf_nodes() if key[0] == app_label]
else:
targets = executor.loader.graph.leaf_nodes()
if options['prune']:
if not options['app_label']:
raise CommandError(
'Migrations can be pruned only when an app is specified.'
)
if self.verbosity > 0:
self.stdout.write('Pruning migrations:', self.style.MIGRATE_HEADING)
to_prune = set(executor.loader.applied_migrations) - set(executor.loader.disk_migrations)
squashed_migrations_with_deleted_replaced_migrations = [
migration_key
for migration_key, migration_obj in executor.loader.replacements.items()
if any(replaced in to_prune for replaced in migration_obj.replaces)
]
if squashed_migrations_with_deleted_replaced_migrations:
self.stdout.write(self.style.NOTICE(
" Cannot use --prune because the following squashed "
"migrations have their 'replaces' attributes and may not "
"be recorded as applied:"
))
for migration in squashed_migrations_with_deleted_replaced_migrations:
app, name = migration
self.stdout.write(f' {app}.{name}')
self.stdout.write(self.style.NOTICE(
" Re-run 'manage.py migrate' if they are not marked as "
"applied, and remove 'replaces' attributes in their "
"Migration classes."
))
else:
to_prune = sorted(
migration
for migration in to_prune
if migration[0] == app_label
)
if to_prune:
for migration in to_prune:
app, name = migration
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_LABEL(
f' Pruning {app}.{name}'
), ending='')
executor.recorder.record_unapplied(app, name)
if self.verbosity > 0:
self.stdout.write(self.style.SUCCESS(' OK'))
elif self.verbosity > 0:
self.stdout.write(' No migrations to prune.')
plan = executor.migration_plan(targets)
exit_dry = plan and options['check_unapplied']
if options['plan']:
self.stdout.write('Planned operations:', self.style.MIGRATE_LABEL)
if not plan:
self.stdout.write(' No planned migration operations.')
for migration, backwards in plan:
self.stdout.write(str(migration), self.style.MIGRATE_HEADING)
for operation in migration.operations:
message, is_error = self.describe_operation(operation, backwards)
style = self.style.WARNING if is_error else None
self.stdout.write(' ' + message, style)
if exit_dry:
sys.exit(1)
return
if exit_dry:
sys.exit(1)
if options['prune']:
return
# At this point, ignore run_syncdb if there aren't any apps to sync.
run_syncdb = options['run_syncdb'] and executor.loader.unmigrated_apps
# Print some useful info
if self.verbosity >= 1:
self.stdout.write(self.style.MIGRATE_HEADING("Operations to perform:"))
if run_syncdb:
if options['app_label']:
self.stdout.write(
self.style.MIGRATE_LABEL(" Synchronize unmigrated app: %s" % app_label)
)
else:
self.stdout.write(
self.style.MIGRATE_LABEL(" Synchronize unmigrated apps: ") +
(", ".join(sorted(executor.loader.unmigrated_apps)))
)
if target_app_labels_only:
self.stdout.write(
self.style.MIGRATE_LABEL(" Apply all migrations: ") +
(", ".join(sorted({a for a, n in targets})) or "(none)")
)
else:
if targets[0][1] is None:
self.stdout.write(
self.style.MIGRATE_LABEL(' Unapply all migrations: ') +
str(targets[0][0])
)
else:
self.stdout.write(self.style.MIGRATE_LABEL(
" Target specific migration: ") + "%s, from %s"
% (targets[0][1], targets[0][0])
)
pre_migrate_state = executor._create_project_state(with_applied_migrations=True)
pre_migrate_apps = pre_migrate_state.apps
emit_pre_migrate_signal(
self.verbosity, self.interactive, connection.alias, stdout=self.stdout, apps=pre_migrate_apps, plan=plan,
)
# Run the syncdb phase.
if run_syncdb:
if self.verbosity >= 1:
self.stdout.write(self.style.MIGRATE_HEADING("Synchronizing apps without migrations:"))
if options['app_label']:
self.sync_apps(connection, [app_label])
else:
self.sync_apps(connection, executor.loader.unmigrated_apps)
# Migrate!
if self.verbosity >= 1:
self.stdout.write(self.style.MIGRATE_HEADING("Running migrations:"))
if not plan:
if self.verbosity >= 1:
self.stdout.write(" No migrations to apply.")
# If there's changes that aren't in migrations yet, tell them how to fix it.
autodetector = MigrationAutodetector(
executor.loader.project_state(),
ProjectState.from_apps(apps),
)
changes = autodetector.changes(graph=executor.loader.graph)
if changes:
self.stdout.write(self.style.NOTICE(
" Your models in app(s): %s have changes that are not "
"yet reflected in a migration, and so won't be "
"applied." % ", ".join(repr(app) for app in sorted(changes))
))
self.stdout.write(self.style.NOTICE(
" Run 'manage.py makemigrations' to make new "
"migrations, and then re-run 'manage.py migrate' to "
"apply them."
))
fake = False
fake_initial = False
else:
fake = options['fake']
fake_initial = options['fake_initial']
post_migrate_state = executor.migrate(
targets, plan=plan, state=pre_migrate_state.clone(), fake=fake,
fake_initial=fake_initial,
)
# post_migrate signals have access to all models. Ensure that all models
# are reloaded in case any are delayed.
post_migrate_state.clear_delayed_apps_cache()
post_migrate_apps = post_migrate_state.apps
# Re-render models of real apps to include relationships now that
# we've got a final state. This wouldn't be necessary if real apps
# models were rendered with relationships in the first place.
with post_migrate_apps.bulk_update():
model_keys = []
for model_state in post_migrate_apps.real_models:
model_key = model_state.app_label, model_state.name_lower
model_keys.append(model_key)
post_migrate_apps.unregister_model(*model_key)
post_migrate_apps.render_multiple([
ModelState.from_model(apps.get_model(*model)) for model in model_keys
])
# Send the post_migrate signal, so individual apps can do whatever they need
# to do at this point.
emit_post_migrate_signal(
self.verbosity, self.interactive, connection.alias, stdout=self.stdout, apps=post_migrate_apps, plan=plan,
)
def migration_progress_callback(self, action, migration=None, fake=False):
if self.verbosity >= 1:
compute_time = self.verbosity > 1
if action == "apply_start":
if compute_time:
self.start = time.monotonic()
self.stdout.write(" Applying %s..." % migration, ending="")
self.stdout.flush()
elif action == "apply_success":
elapsed = " (%.3fs)" % (time.monotonic() - self.start) if compute_time else ""
if fake:
self.stdout.write(self.style.SUCCESS(" FAKED" + elapsed))
else:
self.stdout.write(self.style.SUCCESS(" OK" + elapsed))
elif action == "unapply_start":
if compute_time:
self.start = time.monotonic()
self.stdout.write(" Unapplying %s..." % migration, ending="")
self.stdout.flush()
elif action == "unapply_success":
elapsed = " (%.3fs)" % (time.monotonic() - self.start) if compute_time else ""
if fake:
self.stdout.write(self.style.SUCCESS(" FAKED" + elapsed))
else:
self.stdout.write(self.style.SUCCESS(" OK" + elapsed))
elif action == "render_start":
if compute_time:
self.start = time.monotonic()
self.stdout.write(" Rendering model states...", ending="")
self.stdout.flush()
elif action == "render_success":
elapsed = " (%.3fs)" % (time.monotonic() - self.start) if compute_time else ""
self.stdout.write(self.style.SUCCESS(" DONE" + elapsed))
def sync_apps(self, connection, app_labels):
"""Run the old syncdb-style operation on a list of app_labels."""
with connection.cursor() as cursor:
tables = connection.introspection.table_names(cursor)
# Build the manifest of apps and models that are to be synchronized.
all_models = [
(
app_config.label,
router.get_migratable_models(app_config, connection.alias, include_auto_created=False),
)
for app_config in apps.get_app_configs()
if app_config.models_module is not None and app_config.label in app_labels
]
def model_installed(model):
opts = model._meta
converter = connection.introspection.identifier_converter
return not (
(converter(opts.db_table) in tables) or
(opts.auto_created and converter(opts.auto_created._meta.db_table) in tables)
)
manifest = {
app_name: list(filter(model_installed, model_list))
for app_name, model_list in all_models
}
# Create the tables for each model
if self.verbosity >= 1:
self.stdout.write(' Creating tables...')
with connection.schema_editor() as editor:
for app_name, model_list in manifest.items():
for model in model_list:
# Never install unmanaged models, etc.
if not model._meta.can_migrate(connection):
continue
if self.verbosity >= 3:
self.stdout.write(
' Processing %s.%s model' % (app_name, model._meta.object_name)
)
if self.verbosity >= 1:
self.stdout.write(' Creating table %s' % model._meta.db_table)
editor.create_model(model)
# Deferred SQL is executed when exiting the editor's context.
if self.verbosity >= 1:
self.stdout.write(' Running deferred SQL...')
@staticmethod
def describe_operation(operation, backwards):
"""Return a string that describes a migration operation for --plan."""
prefix = ''
is_error = False
if hasattr(operation, 'code'):
code = operation.reverse_code if backwards else operation.code
action = (code.__doc__ or '') if code else None
elif hasattr(operation, 'sql'):
action = operation.reverse_sql if backwards else operation.sql
else:
action = ''
if backwards:
prefix = 'Undo '
if action is not None:
action = str(action).replace('\n', '')
elif backwards:
action = 'IRREVERSIBLE'
is_error = True
if action:
action = ' -> ' + action
truncated = Truncator(action)
return prefix + operation.describe() + truncated.chars(40), is_error
|
7e3e471cfd39186620a47124ee8e54fcd59b9387f008f5bd9c6da83e2d8bffc9 | import errno
import os
import re
import socket
import sys
from datetime import datetime
from django.conf import settings
from django.core.management.base import BaseCommand, CommandError
from django.core.servers.basehttp import (
WSGIServer, get_internal_wsgi_application, run,
)
from django.utils import autoreload
from django.utils.regex_helper import _lazy_re_compile
naiveip_re = _lazy_re_compile(r"""^(?:
(?P<addr>
(?P<ipv4>\d{1,3}(?:\.\d{1,3}){3}) | # IPv4 address
(?P<ipv6>\[[a-fA-F0-9:]+\]) | # IPv6 address
(?P<fqdn>[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*) # FQDN
):)?(?P<port>\d+)$""", re.X)
class Command(BaseCommand):
help = "Starts a lightweight web server for development."
# Validation is called explicitly each time the server is reloaded.
requires_system_checks = []
stealth_options = ('shutdown_message',)
suppressed_base_arguments = {'--verbosity', '--traceback'}
default_addr = '127.0.0.1'
default_addr_ipv6 = '::1'
default_port = '8000'
protocol = 'http'
server_cls = WSGIServer
def add_arguments(self, parser):
parser.add_argument(
'addrport', nargs='?',
help='Optional port number, or ipaddr:port'
)
parser.add_argument(
'--ipv6', '-6', action='store_true', dest='use_ipv6',
help='Tells Django to use an IPv6 address.',
)
parser.add_argument(
'--nothreading', action='store_false', dest='use_threading',
help='Tells Django to NOT use threading.',
)
parser.add_argument(
'--noreload', action='store_false', dest='use_reloader',
help='Tells Django to NOT use the auto-reloader.',
)
parser.add_argument(
'--skip-checks', action='store_true',
help='Skip system checks.',
)
def execute(self, *args, **options):
if options['no_color']:
# We rely on the environment because it's currently the only
# way to reach WSGIRequestHandler. This seems an acceptable
# compromise considering `runserver` runs indefinitely.
os.environ["DJANGO_COLORS"] = "nocolor"
super().execute(*args, **options)
def get_handler(self, *args, **options):
"""Return the default WSGI handler for the runner."""
return get_internal_wsgi_application()
def handle(self, *args, **options):
if not settings.DEBUG and not settings.ALLOWED_HOSTS:
raise CommandError('You must set settings.ALLOWED_HOSTS if DEBUG is False.')
self.use_ipv6 = options['use_ipv6']
if self.use_ipv6 and not socket.has_ipv6:
raise CommandError('Your Python does not support IPv6.')
self._raw_ipv6 = False
if not options['addrport']:
self.addr = ''
self.port = self.default_port
else:
m = re.match(naiveip_re, options['addrport'])
if m is None:
raise CommandError('"%s" is not a valid port number '
'or address:port pair.' % options['addrport'])
self.addr, _ipv4, _ipv6, _fqdn, self.port = m.groups()
if not self.port.isdigit():
raise CommandError("%r is not a valid port number." % self.port)
if self.addr:
if _ipv6:
self.addr = self.addr[1:-1]
self.use_ipv6 = True
self._raw_ipv6 = True
elif self.use_ipv6 and not _fqdn:
raise CommandError('"%s" is not a valid IPv6 address.' % self.addr)
if not self.addr:
self.addr = self.default_addr_ipv6 if self.use_ipv6 else self.default_addr
self._raw_ipv6 = self.use_ipv6
self.run(**options)
def run(self, **options):
"""Run the server, using the autoreloader if needed."""
use_reloader = options['use_reloader']
if use_reloader:
autoreload.run_with_reloader(self.inner_run, **options)
else:
self.inner_run(None, **options)
def inner_run(self, *args, **options):
# If an exception was silenced in ManagementUtility.execute in order
# to be raised in the child process, raise it now.
autoreload.raise_last_exception()
threading = options['use_threading']
# 'shutdown_message' is a stealth option.
shutdown_message = options.get('shutdown_message', '')
quit_command = 'CTRL-BREAK' if sys.platform == 'win32' else 'CONTROL-C'
if not options['skip_checks']:
self.stdout.write('Performing system checks...\n\n')
self.check(display_num_errors=True)
# Need to check migrations here, so can't use the
# requires_migrations_check attribute.
self.check_migrations()
now = datetime.now().strftime('%B %d, %Y - %X')
self.stdout.write(now)
self.stdout.write((
"Django version %(version)s, using settings %(settings)r\n"
"Starting development server at %(protocol)s://%(addr)s:%(port)s/\n"
"Quit the server with %(quit_command)s."
) % {
"version": self.get_version(),
"settings": settings.SETTINGS_MODULE,
"protocol": self.protocol,
"addr": '[%s]' % self.addr if self._raw_ipv6 else self.addr,
"port": self.port,
"quit_command": quit_command,
})
try:
handler = self.get_handler(*args, **options)
run(self.addr, int(self.port), handler,
ipv6=self.use_ipv6, threading=threading, server_cls=self.server_cls)
except OSError as e:
# Use helpful error messages instead of ugly tracebacks.
ERRORS = {
errno.EACCES: "You don't have permission to access that port.",
errno.EADDRINUSE: "That port is already in use.",
errno.EADDRNOTAVAIL: "That IP address can't be assigned to.",
}
try:
error_text = ERRORS[e.errno]
except KeyError:
error_text = e
self.stderr.write("Error: %s" % error_text)
# Need to use an OS exit because sys.exit doesn't work in a thread
os._exit(1)
except KeyboardInterrupt:
if shutdown_message:
self.stdout.write(shutdown_message)
sys.exit(0)
|
5597cb62f79e797d2f58ee62156a293ffe53acd669cbed2c8ff0c3979e4cebaf | import os
from django.apps import apps
from django.conf import settings
from django.core.management.base import BaseCommand, CommandError
from django.db import DEFAULT_DB_ALIAS, connections, migrations
from django.db.migrations.loader import AmbiguityError, MigrationLoader
from django.db.migrations.migration import SwappableTuple
from django.db.migrations.optimizer import MigrationOptimizer
from django.db.migrations.writer import MigrationWriter
from django.utils.version import get_docs_version
class Command(BaseCommand):
help = "Squashes an existing set of migrations (from first until specified) into a single new one."
def add_arguments(self, parser):
parser.add_argument(
'app_label',
help='App label of the application to squash migrations for.',
)
parser.add_argument(
'start_migration_name', nargs='?',
help='Migrations will be squashed starting from and including this migration.',
)
parser.add_argument(
'migration_name',
help='Migrations will be squashed until and including this migration.',
)
parser.add_argument(
'--no-optimize', action='store_true',
help='Do not try to optimize the squashed operations.',
)
parser.add_argument(
'--noinput', '--no-input', action='store_false', dest='interactive',
help='Tells Django to NOT prompt the user for input of any kind.',
)
parser.add_argument(
'--squashed-name',
help='Sets the name of the new squashed migration.',
)
parser.add_argument(
'--no-header', action='store_false', dest='include_header',
help='Do not add a header comment to the new squashed migration.',
)
def handle(self, **options):
self.verbosity = options['verbosity']
self.interactive = options['interactive']
app_label = options['app_label']
start_migration_name = options['start_migration_name']
migration_name = options['migration_name']
no_optimize = options['no_optimize']
squashed_name = options['squashed_name']
include_header = options['include_header']
# Validate app_label.
try:
apps.get_app_config(app_label)
except LookupError as err:
raise CommandError(str(err))
# Load the current graph state, check the app and migration they asked for exists
loader = MigrationLoader(connections[DEFAULT_DB_ALIAS])
if app_label not in loader.migrated_apps:
raise CommandError(
"App '%s' does not have migrations (so squashmigrations on "
"it makes no sense)" % app_label
)
migration = self.find_migration(loader, app_label, migration_name)
# Work out the list of predecessor migrations
migrations_to_squash = [
loader.get_migration(al, mn)
for al, mn in loader.graph.forwards_plan((migration.app_label, migration.name))
if al == migration.app_label
]
if start_migration_name:
start_migration = self.find_migration(loader, app_label, start_migration_name)
start = loader.get_migration(start_migration.app_label, start_migration.name)
try:
start_index = migrations_to_squash.index(start)
migrations_to_squash = migrations_to_squash[start_index:]
except ValueError:
raise CommandError(
"The migration '%s' cannot be found. Maybe it comes after "
"the migration '%s'?\n"
"Have a look at:\n"
" python manage.py showmigrations %s\n"
"to debug this issue." % (start_migration, migration, app_label)
)
# Tell them what we're doing and optionally ask if we should proceed
if self.verbosity > 0 or self.interactive:
self.stdout.write(self.style.MIGRATE_HEADING("Will squash the following migrations:"))
for migration in migrations_to_squash:
self.stdout.write(" - %s" % migration.name)
if self.interactive:
answer = None
while not answer or answer not in "yn":
answer = input("Do you wish to proceed? [yN] ")
if not answer:
answer = "n"
break
else:
answer = answer[0].lower()
if answer != "y":
return
# Load the operations from all those migrations and concat together,
# along with collecting external dependencies and detecting
# double-squashing
operations = []
dependencies = set()
# We need to take all dependencies from the first migration in the list
# as it may be 0002 depending on 0001
first_migration = True
for smigration in migrations_to_squash:
if smigration.replaces:
raise CommandError(
"You cannot squash squashed migrations! Please transition "
"it to a normal migration first: "
"https://docs.djangoproject.com/en/%s/topics/migrations/#squashing-migrations" % get_docs_version()
)
operations.extend(smigration.operations)
for dependency in smigration.dependencies:
if isinstance(dependency, SwappableTuple):
if settings.AUTH_USER_MODEL == dependency.setting:
dependencies.add(("__setting__", "AUTH_USER_MODEL"))
else:
dependencies.add(dependency)
elif dependency[0] != smigration.app_label or first_migration:
dependencies.add(dependency)
first_migration = False
if no_optimize:
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("(Skipping optimization.)"))
new_operations = operations
else:
if self.verbosity > 0:
self.stdout.write(self.style.MIGRATE_HEADING("Optimizing..."))
optimizer = MigrationOptimizer()
new_operations = optimizer.optimize(operations, migration.app_label)
if self.verbosity > 0:
if len(new_operations) == len(operations):
self.stdout.write(" No optimizations possible.")
else:
self.stdout.write(
" Optimized from %s operations to %s operations." %
(len(operations), len(new_operations))
)
# Work out the value of replaces (any squashed ones we're re-squashing)
# need to feed their replaces into ours
replaces = []
for migration in migrations_to_squash:
if migration.replaces:
replaces.extend(migration.replaces)
else:
replaces.append((migration.app_label, migration.name))
# Make a new migration with those operations
subclass = type("Migration", (migrations.Migration,), {
"dependencies": dependencies,
"operations": new_operations,
"replaces": replaces,
})
if start_migration_name:
if squashed_name:
# Use the name from --squashed-name.
prefix, _ = start_migration.name.split('_', 1)
name = '%s_%s' % (prefix, squashed_name)
else:
# Generate a name.
name = '%s_squashed_%s' % (start_migration.name, migration.name)
new_migration = subclass(name, app_label)
else:
name = '0001_%s' % (squashed_name or 'squashed_%s' % migration.name)
new_migration = subclass(name, app_label)
new_migration.initial = True
# Write out the new migration file
writer = MigrationWriter(new_migration, include_header)
if os.path.exists(writer.path):
raise CommandError(
f'Migration {new_migration.name} already exists. Use a different name.'
)
with open(writer.path, "w", encoding='utf-8') as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.stdout.write(
self.style.MIGRATE_HEADING('Created new squashed migration %s' % writer.path) + '\n'
' You should commit this migration but leave the old ones in place;\n'
' the new migration will be used for new installs. Once you are sure\n'
' all instances of the codebase have applied the migrations you squashed,\n'
' you can delete them.'
)
if writer.needs_manual_porting:
self.stdout.write(
self.style.MIGRATE_HEADING('Manual porting required') + '\n'
' Your migrations contained functions that must be manually copied over,\n'
' as we could not safely copy their implementation.\n'
' See the comment at the top of the squashed migration for details.'
)
def find_migration(self, loader, app_label, name):
try:
return loader.get_migration_by_prefix(app_label, name)
except AmbiguityError:
raise CommandError(
"More than one migration matches '%s' in app '%s'. Please be "
"more specific." % (name, app_label)
)
except KeyError:
raise CommandError(
"Cannot find a migration matching '%s' from app '%s'." %
(name, app_label)
)
|
504068a178ba8855e5fe5dd6997a6b59f8238f9df0aee36e3ea8432e3f5eeaae | import sys
from django.conf import settings
from django.core.management.base import BaseCommand
from django.core.management.utils import get_command_line_option
from django.test.runner import get_max_test_processes
from django.test.utils import NullTimeKeeper, TimeKeeper, get_runner
class Command(BaseCommand):
help = 'Discover and run tests in the specified modules or the current directory.'
# DiscoverRunner runs the checks after databases are set up.
requires_system_checks = []
test_runner = None
def run_from_argv(self, argv):
"""
Pre-parse the command line to extract the value of the --testrunner
option. This allows a test runner to define additional command line
arguments.
"""
self.test_runner = get_command_line_option(argv, '--testrunner')
super().run_from_argv(argv)
def add_arguments(self, parser):
parser.add_argument(
'args', metavar='test_label', nargs='*',
help='Module paths to test; can be modulename, modulename.TestCase or modulename.TestCase.test_method'
)
parser.add_argument(
'--noinput', '--no-input', action='store_false', dest='interactive',
help='Tells Django to NOT prompt the user for input of any kind.',
)
parser.add_argument(
'--failfast', action='store_true',
help='Tells Django to stop running the test suite after first failed test.',
)
parser.add_argument(
'--testrunner',
help='Tells Django to use specified test runner class instead of '
'the one specified by the TEST_RUNNER setting.',
)
test_runner_class = get_runner(settings, self.test_runner)
if hasattr(test_runner_class, 'add_arguments'):
test_runner_class.add_arguments(parser)
def handle(self, *test_labels, **options):
TestRunner = get_runner(settings, options['testrunner'])
time_keeper = TimeKeeper() if options.get('timing', False) else NullTimeKeeper()
parallel = options.get('parallel')
if parallel == 'auto':
options['parallel'] = get_max_test_processes()
test_runner = TestRunner(**options)
with time_keeper.timed('Total run'):
failures = test_runner.run_tests(test_labels)
time_keeper.print_results()
if failures:
sys.exit(1)
|
b0d55e0c1990d6a8bdf2e0701c78dbebb08cfa9412d2de5f168741dc7deee565 | import glob
import os
import re
import sys
from functools import total_ordering
from itertools import dropwhile
from pathlib import Path
import django
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.core.files.temp import NamedTemporaryFile
from django.core.management.base import BaseCommand, CommandError
from django.core.management.utils import (
find_command, handle_extensions, is_ignored_path, popen_wrapper,
)
from django.utils.encoding import DEFAULT_LOCALE_ENCODING
from django.utils.functional import cached_property
from django.utils.jslex import prepare_js_for_gettext
from django.utils.regex_helper import _lazy_re_compile
from django.utils.text import get_text_list
from django.utils.translation import templatize
plural_forms_re = _lazy_re_compile(r'^(?P<value>"Plural-Forms.+?\\n")\s*$', re.MULTILINE | re.DOTALL)
STATUS_OK = 0
NO_LOCALE_DIR = object()
def check_programs(*programs):
for program in programs:
if find_command(program) is None:
raise CommandError(
"Can't find %s. Make sure you have GNU gettext tools 0.15 or "
"newer installed." % program
)
@total_ordering
class TranslatableFile:
def __init__(self, dirpath, file_name, locale_dir):
self.file = file_name
self.dirpath = dirpath
self.locale_dir = locale_dir
def __repr__(self):
return "<%s: %s>" % (
self.__class__.__name__,
os.sep.join([self.dirpath, self.file]),
)
def __eq__(self, other):
return self.path == other.path
def __lt__(self, other):
return self.path < other.path
@property
def path(self):
return os.path.join(self.dirpath, self.file)
class BuildFile:
"""
Represent the state of a translatable file during the build process.
"""
def __init__(self, command, domain, translatable):
self.command = command
self.domain = domain
self.translatable = translatable
@cached_property
def is_templatized(self):
if self.domain == 'djangojs':
return self.command.gettext_version < (0, 18, 3)
elif self.domain == 'django':
file_ext = os.path.splitext(self.translatable.file)[1]
return file_ext != '.py'
return False
@cached_property
def path(self):
return self.translatable.path
@cached_property
def work_path(self):
"""
Path to a file which is being fed into GNU gettext pipeline. This may
be either a translatable or its preprocessed version.
"""
if not self.is_templatized:
return self.path
extension = {
'djangojs': 'c',
'django': 'py',
}.get(self.domain)
filename = '%s.%s' % (self.translatable.file, extension)
return os.path.join(self.translatable.dirpath, filename)
def preprocess(self):
"""
Preprocess (if necessary) a translatable file before passing it to
xgettext GNU gettext utility.
"""
if not self.is_templatized:
return
with open(self.path, encoding='utf-8') as fp:
src_data = fp.read()
if self.domain == 'djangojs':
content = prepare_js_for_gettext(src_data)
elif self.domain == 'django':
content = templatize(src_data, origin=self.path[2:])
with open(self.work_path, 'w', encoding='utf-8') as fp:
fp.write(content)
def postprocess_messages(self, msgs):
"""
Postprocess messages generated by xgettext GNU gettext utility.
Transform paths as if these messages were generated from original
translatable files rather than from preprocessed versions.
"""
if not self.is_templatized:
return msgs
# Remove '.py' suffix
if os.name == 'nt':
# Preserve '.\' prefix on Windows to respect gettext behavior
old_path = self.work_path
new_path = self.path
else:
old_path = self.work_path[2:]
new_path = self.path[2:]
return re.sub(
r'^(#: .*)(' + re.escape(old_path) + r')',
lambda match: match[0].replace(old_path, new_path),
msgs,
flags=re.MULTILINE
)
def cleanup(self):
"""
Remove a preprocessed copy of a translatable file (if any).
"""
if self.is_templatized:
# This check is needed for the case of a symlinked file and its
# source being processed inside a single group (locale dir);
# removing either of those two removes both.
if os.path.exists(self.work_path):
os.unlink(self.work_path)
def normalize_eols(raw_contents):
"""
Take a block of raw text that will be passed through str.splitlines() to
get universal newlines treatment.
Return the resulting block of text with normalized `\n` EOL sequences ready
to be written to disk using current platform's native EOLs.
"""
lines_list = raw_contents.splitlines()
# Ensure last line has its EOL
if lines_list and lines_list[-1]:
lines_list.append('')
return '\n'.join(lines_list)
def write_pot_file(potfile, msgs):
"""
Write the `potfile` with the `msgs` contents, making sure its format is
valid.
"""
pot_lines = msgs.splitlines()
if os.path.exists(potfile):
# Strip the header
lines = dropwhile(len, pot_lines)
else:
lines = []
found, header_read = False, False
for line in pot_lines:
if not found and not header_read:
if 'charset=CHARSET' in line:
found = True
line = line.replace('charset=CHARSET', 'charset=UTF-8')
if not line and not found:
header_read = True
lines.append(line)
msgs = '\n'.join(lines)
# Force newlines of POT files to '\n' to work around
# https://savannah.gnu.org/bugs/index.php?52395
with open(potfile, 'a', encoding='utf-8', newline='\n') as fp:
fp.write(msgs)
class Command(BaseCommand):
help = (
"Runs over the entire source tree of the current directory and "
"pulls out all strings marked for translation. It creates (or updates) a message "
"file in the conf/locale (in the django tree) or locale (for projects and "
"applications) directory.\n\nYou must run this command with one of either the "
"--locale, --exclude, or --all options."
)
translatable_file_class = TranslatableFile
build_file_class = BuildFile
requires_system_checks = []
msgmerge_options = ['-q', '--backup=none', '--previous', '--update']
msguniq_options = ['--to-code=utf-8']
msgattrib_options = ['--no-obsolete']
xgettext_options = ['--from-code=UTF-8', '--add-comments=Translators']
def add_arguments(self, parser):
parser.add_argument(
'--locale', '-l', default=[], action='append',
help='Creates or updates the message files for the given locale(s) (e.g. pt_BR). '
'Can be used multiple times.',
)
parser.add_argument(
'--exclude', '-x', default=[], action='append',
help='Locales to exclude. Default is none. Can be used multiple times.',
)
parser.add_argument(
'--domain', '-d', default='django',
help='The domain of the message files (default: "django").',
)
parser.add_argument(
'--all', '-a', action='store_true',
help='Updates the message files for all existing locales.',
)
parser.add_argument(
'--extension', '-e', dest='extensions', action='append',
help='The file extension(s) to examine (default: "html,txt,py", or "js" '
'if the domain is "djangojs"). Separate multiple extensions with '
'commas, or use -e multiple times.',
)
parser.add_argument(
'--symlinks', '-s', action='store_true',
help='Follows symlinks to directories when examining source code '
'and templates for translation strings.',
)
parser.add_argument(
'--ignore', '-i', action='append', dest='ignore_patterns',
default=[], metavar='PATTERN',
help='Ignore files or directories matching this glob-style pattern. '
'Use multiple times to ignore more.',
)
parser.add_argument(
'--no-default-ignore', action='store_false', dest='use_default_ignore_patterns',
help="Don't ignore the common glob-style patterns 'CVS', '.*', '*~' and '*.pyc'.",
)
parser.add_argument(
'--no-wrap', action='store_true',
help="Don't break long message lines into several lines.",
)
parser.add_argument(
'--no-location', action='store_true',
help="Don't write '#: filename:line' lines.",
)
parser.add_argument(
'--add-location',
choices=('full', 'file', 'never'), const='full', nargs='?',
help=(
"Controls '#: filename:line' lines. If the option is 'full' "
"(the default if not given), the lines include both file name "
"and line number. If it's 'file', the line number is omitted. If "
"it's 'never', the lines are suppressed (same as --no-location). "
"--add-location requires gettext 0.19 or newer."
),
)
parser.add_argument(
'--no-obsolete', action='store_true',
help="Remove obsolete message strings.",
)
parser.add_argument(
'--keep-pot', action='store_true',
help="Keep .pot file after making messages. Useful when debugging.",
)
def handle(self, *args, **options):
locale = options['locale']
exclude = options['exclude']
self.domain = options['domain']
self.verbosity = options['verbosity']
process_all = options['all']
extensions = options['extensions']
self.symlinks = options['symlinks']
ignore_patterns = options['ignore_patterns']
if options['use_default_ignore_patterns']:
ignore_patterns += ['CVS', '.*', '*~', '*.pyc']
self.ignore_patterns = list(set(ignore_patterns))
# Avoid messing with mutable class variables
if options['no_wrap']:
self.msgmerge_options = self.msgmerge_options[:] + ['--no-wrap']
self.msguniq_options = self.msguniq_options[:] + ['--no-wrap']
self.msgattrib_options = self.msgattrib_options[:] + ['--no-wrap']
self.xgettext_options = self.xgettext_options[:] + ['--no-wrap']
if options['no_location']:
self.msgmerge_options = self.msgmerge_options[:] + ['--no-location']
self.msguniq_options = self.msguniq_options[:] + ['--no-location']
self.msgattrib_options = self.msgattrib_options[:] + ['--no-location']
self.xgettext_options = self.xgettext_options[:] + ['--no-location']
if options['add_location']:
if self.gettext_version < (0, 19):
raise CommandError(
"The --add-location option requires gettext 0.19 or later. "
"You have %s." % '.'.join(str(x) for x in self.gettext_version)
)
arg_add_location = "--add-location=%s" % options['add_location']
self.msgmerge_options = self.msgmerge_options[:] + [arg_add_location]
self.msguniq_options = self.msguniq_options[:] + [arg_add_location]
self.msgattrib_options = self.msgattrib_options[:] + [arg_add_location]
self.xgettext_options = self.xgettext_options[:] + [arg_add_location]
self.no_obsolete = options['no_obsolete']
self.keep_pot = options['keep_pot']
if self.domain not in ('django', 'djangojs'):
raise CommandError("currently makemessages only supports domains "
"'django' and 'djangojs'")
if self.domain == 'djangojs':
exts = extensions or ['js']
else:
exts = extensions or ['html', 'txt', 'py']
self.extensions = handle_extensions(exts)
if (not locale and not exclude and not process_all) or self.domain is None:
raise CommandError(
"Type '%s help %s' for usage information."
% (os.path.basename(sys.argv[0]), sys.argv[1])
)
if self.verbosity > 1:
self.stdout.write(
'examining files with the extensions: %s'
% get_text_list(list(self.extensions), 'and')
)
self.invoked_for_django = False
self.locale_paths = []
self.default_locale_path = None
if os.path.isdir(os.path.join('conf', 'locale')):
self.locale_paths = [os.path.abspath(os.path.join('conf', 'locale'))]
self.default_locale_path = self.locale_paths[0]
self.invoked_for_django = True
else:
if self.settings_available:
self.locale_paths.extend(settings.LOCALE_PATHS)
# Allow to run makemessages inside an app dir
if os.path.isdir('locale'):
self.locale_paths.append(os.path.abspath('locale'))
if self.locale_paths:
self.default_locale_path = self.locale_paths[0]
os.makedirs(self.default_locale_path, exist_ok=True)
# Build locale list
looks_like_locale = re.compile(r'[a-z]{2}')
locale_dirs = filter(os.path.isdir, glob.glob('%s/*' % self.default_locale_path))
all_locales = [
lang_code for lang_code in map(os.path.basename, locale_dirs)
if looks_like_locale.match(lang_code)
]
# Account for excluded locales
if process_all:
locales = all_locales
else:
locales = locale or all_locales
locales = set(locales).difference(exclude)
if locales:
check_programs('msguniq', 'msgmerge', 'msgattrib')
check_programs('xgettext')
try:
potfiles = self.build_potfiles()
# Build po files for each selected locale
for locale in locales:
if '-' in locale:
self.stdout.write(
'invalid locale %s, did you mean %s?' % (
locale,
locale.replace('-', '_'),
),
)
continue
if self.verbosity > 0:
self.stdout.write('processing locale %s' % locale)
for potfile in potfiles:
self.write_po_file(potfile, locale)
finally:
if not self.keep_pot:
self.remove_potfiles()
@cached_property
def gettext_version(self):
# Gettext tools will output system-encoded bytestrings instead of UTF-8,
# when looking up the version. It's especially a problem on Windows.
out, err, status = popen_wrapper(
['xgettext', '--version'],
stdout_encoding=DEFAULT_LOCALE_ENCODING,
)
m = re.search(r'(\d+)\.(\d+)\.?(\d+)?', out)
if m:
return tuple(int(d) for d in m.groups() if d is not None)
else:
raise CommandError("Unable to get gettext version. Is it installed?")
@cached_property
def settings_available(self):
try:
settings.LOCALE_PATHS
except ImproperlyConfigured:
if self.verbosity > 1:
self.stderr.write("Running without configured settings.")
return False
return True
def build_potfiles(self):
"""
Build pot files and apply msguniq to them.
"""
file_list = self.find_files(".")
self.remove_potfiles()
self.process_files(file_list)
potfiles = []
for path in self.locale_paths:
potfile = os.path.join(path, '%s.pot' % self.domain)
if not os.path.exists(potfile):
continue
args = ['msguniq'] + self.msguniq_options + [potfile]
msgs, errors, status = popen_wrapper(args)
if errors:
if status != STATUS_OK:
raise CommandError(
"errors happened while running msguniq\n%s" % errors)
elif self.verbosity > 0:
self.stdout.write(errors)
msgs = normalize_eols(msgs)
with open(potfile, 'w', encoding='utf-8') as fp:
fp.write(msgs)
potfiles.append(potfile)
return potfiles
def remove_potfiles(self):
for path in self.locale_paths:
pot_path = os.path.join(path, '%s.pot' % self.domain)
if os.path.exists(pot_path):
os.unlink(pot_path)
def find_files(self, root):
"""
Get all files in the given root. Also check that there is a matching
locale dir for each file.
"""
all_files = []
ignored_roots = []
if self.settings_available:
ignored_roots = [os.path.normpath(p) for p in (settings.MEDIA_ROOT, settings.STATIC_ROOT) if p]
for dirpath, dirnames, filenames in os.walk(root, topdown=True, followlinks=self.symlinks):
for dirname in dirnames[:]:
if (is_ignored_path(os.path.normpath(os.path.join(dirpath, dirname)), self.ignore_patterns) or
os.path.join(os.path.abspath(dirpath), dirname) in ignored_roots):
dirnames.remove(dirname)
if self.verbosity > 1:
self.stdout.write('ignoring directory %s' % dirname)
elif dirname == 'locale':
dirnames.remove(dirname)
self.locale_paths.insert(0, os.path.join(os.path.abspath(dirpath), dirname))
for filename in filenames:
file_path = os.path.normpath(os.path.join(dirpath, filename))
file_ext = os.path.splitext(filename)[1]
if file_ext not in self.extensions or is_ignored_path(file_path, self.ignore_patterns):
if self.verbosity > 1:
self.stdout.write('ignoring file %s in %s' % (filename, dirpath))
else:
locale_dir = None
for path in self.locale_paths:
if os.path.abspath(dirpath).startswith(os.path.dirname(path)):
locale_dir = path
break
locale_dir = locale_dir or self.default_locale_path or NO_LOCALE_DIR
all_files.append(self.translatable_file_class(dirpath, filename, locale_dir))
return sorted(all_files)
def process_files(self, file_list):
"""
Group translatable files by locale directory and run pot file build
process for each group.
"""
file_groups = {}
for translatable in file_list:
file_group = file_groups.setdefault(translatable.locale_dir, [])
file_group.append(translatable)
for locale_dir, files in file_groups.items():
self.process_locale_dir(locale_dir, files)
def process_locale_dir(self, locale_dir, files):
"""
Extract translatable literals from the specified files, creating or
updating the POT file for a given locale directory.
Use the xgettext GNU gettext utility.
"""
build_files = []
for translatable in files:
if self.verbosity > 1:
self.stdout.write('processing file %s in %s' % (
translatable.file, translatable.dirpath
))
if self.domain not in ('djangojs', 'django'):
continue
build_file = self.build_file_class(self, self.domain, translatable)
try:
build_file.preprocess()
except UnicodeDecodeError as e:
self.stdout.write(
'UnicodeDecodeError: skipped file %s in %s (reason: %s)' % (
translatable.file, translatable.dirpath, e,
)
)
continue
except BaseException:
# Cleanup before exit.
for build_file in build_files:
build_file.cleanup()
raise
build_files.append(build_file)
if self.domain == 'djangojs':
is_templatized = build_file.is_templatized
args = [
'xgettext',
'-d', self.domain,
'--language=%s' % ('C' if is_templatized else 'JavaScript',),
'--keyword=gettext_noop',
'--keyword=gettext_lazy',
'--keyword=ngettext_lazy:1,2',
'--keyword=pgettext:1c,2',
'--keyword=npgettext:1c,2,3',
'--output=-',
]
elif self.domain == 'django':
args = [
'xgettext',
'-d', self.domain,
'--language=Python',
'--keyword=gettext_noop',
'--keyword=gettext_lazy',
'--keyword=ngettext_lazy:1,2',
'--keyword=pgettext:1c,2',
'--keyword=npgettext:1c,2,3',
'--keyword=pgettext_lazy:1c,2',
'--keyword=npgettext_lazy:1c,2,3',
'--output=-',
]
else:
return
input_files = [bf.work_path for bf in build_files]
with NamedTemporaryFile(mode='w+') as input_files_list:
input_files_list.write('\n'.join(input_files))
input_files_list.flush()
args.extend(['--files-from', input_files_list.name])
args.extend(self.xgettext_options)
msgs, errors, status = popen_wrapper(args)
if errors:
if status != STATUS_OK:
for build_file in build_files:
build_file.cleanup()
raise CommandError(
'errors happened while running xgettext on %s\n%s' %
('\n'.join(input_files), errors)
)
elif self.verbosity > 0:
# Print warnings
self.stdout.write(errors)
if msgs:
if locale_dir is NO_LOCALE_DIR:
for build_file in build_files:
build_file.cleanup()
file_path = os.path.normpath(build_files[0].path)
raise CommandError(
"Unable to find a locale path to store translations for "
"file %s. Make sure the 'locale' directory exists in an "
"app or LOCALE_PATHS setting is set." % file_path
)
for build_file in build_files:
msgs = build_file.postprocess_messages(msgs)
potfile = os.path.join(locale_dir, '%s.pot' % self.domain)
write_pot_file(potfile, msgs)
for build_file in build_files:
build_file.cleanup()
def write_po_file(self, potfile, locale):
"""
Create or update the PO file for self.domain and `locale`.
Use contents of the existing `potfile`.
Use msgmerge and msgattrib GNU gettext utilities.
"""
basedir = os.path.join(os.path.dirname(potfile), locale, 'LC_MESSAGES')
os.makedirs(basedir, exist_ok=True)
pofile = os.path.join(basedir, '%s.po' % self.domain)
if os.path.exists(pofile):
args = ['msgmerge'] + self.msgmerge_options + [pofile, potfile]
_, errors, status = popen_wrapper(args)
if errors:
if status != STATUS_OK:
raise CommandError(
"errors happened while running msgmerge\n%s" % errors)
elif self.verbosity > 0:
self.stdout.write(errors)
msgs = Path(pofile).read_text(encoding='utf-8')
else:
with open(potfile, encoding='utf-8') as fp:
msgs = fp.read()
if not self.invoked_for_django:
msgs = self.copy_plural_forms(msgs, locale)
msgs = normalize_eols(msgs)
msgs = msgs.replace(
"#. #-#-#-#-# %s.pot (PACKAGE VERSION) #-#-#-#-#\n" % self.domain, "")
with open(pofile, 'w', encoding='utf-8') as fp:
fp.write(msgs)
if self.no_obsolete:
args = ['msgattrib'] + self.msgattrib_options + ['-o', pofile, pofile]
msgs, errors, status = popen_wrapper(args)
if errors:
if status != STATUS_OK:
raise CommandError(
"errors happened while running msgattrib\n%s" % errors)
elif self.verbosity > 0:
self.stdout.write(errors)
def copy_plural_forms(self, msgs, locale):
"""
Copy plural forms header contents from a Django catalog of locale to
the msgs string, inserting it at the right place. msgs should be the
contents of a newly created .po file.
"""
django_dir = os.path.normpath(os.path.join(os.path.dirname(django.__file__)))
if self.domain == 'djangojs':
domains = ('djangojs', 'django')
else:
domains = ('django',)
for domain in domains:
django_po = os.path.join(django_dir, 'conf', 'locale', locale, 'LC_MESSAGES', '%s.po' % domain)
if os.path.exists(django_po):
with open(django_po, encoding='utf-8') as fp:
m = plural_forms_re.search(fp.read())
if m:
plural_form_line = m['value']
if self.verbosity > 1:
self.stdout.write('copying plural forms: %s' % plural_form_line)
lines = []
found = False
for line in msgs.splitlines():
if not found and (not line or plural_forms_re.search(line)):
line = plural_form_line
found = True
lines.append(line)
msgs = '\n'.join(lines)
break
return msgs
|
7c2859df2784edbf06fd0e3780dbe441d2172b138fccfd23d5f6b1d5dc03047e | import keyword
import re
from django.core.management.base import BaseCommand, CommandError
from django.db import DEFAULT_DB_ALIAS, connections
from django.db.models.constants import LOOKUP_SEP
class Command(BaseCommand):
help = "Introspects the database tables in the given database and outputs a Django model module."
requires_system_checks = []
stealth_options = ('table_name_filter',)
db_module = 'django.db'
def add_arguments(self, parser):
parser.add_argument(
'table', nargs='*', type=str,
help='Selects what tables or views should be introspected.',
)
parser.add_argument(
'--database', default=DEFAULT_DB_ALIAS,
help='Nominates a database to introspect. Defaults to using the "default" database.',
)
parser.add_argument(
'--include-partitions', action='store_true', help='Also output models for partition tables.',
)
parser.add_argument(
'--include-views', action='store_true', help='Also output models for database views.',
)
def handle(self, **options):
try:
for line in self.handle_inspection(options):
self.stdout.write(line)
except NotImplementedError:
raise CommandError("Database inspection isn't supported for the currently selected database backend.")
def handle_inspection(self, options):
connection = connections[options['database']]
# 'table_name_filter' is a stealth option
table_name_filter = options.get('table_name_filter')
def table2model(table_name):
return re.sub(r'[^a-zA-Z0-9]', '', table_name.title())
with connection.cursor() as cursor:
yield "# This is an auto-generated Django model module."
yield "# You'll have to do the following manually to clean this up:"
yield "# * Rearrange models' order"
yield "# * Make sure each model has one field with primary_key=True"
yield "# * Make sure each ForeignKey and OneToOneField has `on_delete` set to the desired behavior"
yield (
"# * Remove `managed = False` lines if you wish to allow "
"Django to create, modify, and delete the table"
)
yield "# Feel free to rename the models, but don't rename db_table values or field names."
yield 'from %s import models' % self.db_module
known_models = []
table_info = connection.introspection.get_table_list(cursor)
# Determine types of tables and/or views to be introspected.
types = {'t'}
if options['include_partitions']:
types.add('p')
if options['include_views']:
types.add('v')
for table_name in (options['table'] or sorted(info.name for info in table_info if info.type in types)):
if table_name_filter is not None and callable(table_name_filter):
if not table_name_filter(table_name):
continue
try:
try:
relations = connection.introspection.get_relations(cursor, table_name)
except NotImplementedError:
relations = {}
try:
constraints = connection.introspection.get_constraints(cursor, table_name)
except NotImplementedError:
constraints = {}
primary_key_column = connection.introspection.get_primary_key_column(cursor, table_name)
unique_columns = [
c['columns'][0] for c in constraints.values()
if c['unique'] and len(c['columns']) == 1
]
table_description = connection.introspection.get_table_description(cursor, table_name)
except Exception as e:
yield "# Unable to inspect table '%s'" % table_name
yield "# The error was: %s" % e
continue
yield ''
yield ''
yield 'class %s(models.Model):' % table2model(table_name)
known_models.append(table2model(table_name))
used_column_names = [] # Holds column names used in the table so far
column_to_field_name = {} # Maps column names to names of model fields
for row in table_description:
comment_notes = [] # Holds Field notes, to be displayed in a Python comment.
extra_params = {} # Holds Field parameters such as 'db_column'.
column_name = row.name
is_relation = column_name in relations
att_name, params, notes = self.normalize_col_name(
column_name, used_column_names, is_relation)
extra_params.update(params)
comment_notes.extend(notes)
used_column_names.append(att_name)
column_to_field_name[column_name] = att_name
# Add primary_key and unique, if necessary.
if column_name == primary_key_column:
extra_params['primary_key'] = True
elif column_name in unique_columns:
extra_params['unique'] = True
if is_relation:
ref_db_column, ref_db_table = relations[column_name]
if extra_params.pop('unique', False) or extra_params.get('primary_key'):
rel_type = 'OneToOneField'
else:
rel_type = 'ForeignKey'
ref_pk_column = connection.introspection.get_primary_key_column(cursor, ref_db_table)
if ref_pk_column and ref_pk_column != ref_db_column:
extra_params['to_field'] = ref_db_column
rel_to = (
'self' if ref_db_table == table_name
else table2model(ref_db_table)
)
if rel_to in known_models:
field_type = '%s(%s' % (rel_type, rel_to)
else:
field_type = "%s('%s'" % (rel_type, rel_to)
else:
# Calling `get_field_type` to get the field type string and any
# additional parameters and notes.
field_type, field_params, field_notes = self.get_field_type(connection, table_name, row)
extra_params.update(field_params)
comment_notes.extend(field_notes)
field_type += '('
# Don't output 'id = meta.AutoField(primary_key=True)', because
# that's assumed if it doesn't exist.
if att_name == 'id' and extra_params == {'primary_key': True}:
if field_type == 'AutoField(':
continue
elif field_type == connection.features.introspected_field_types['AutoField'] + '(':
comment_notes.append('AutoField?')
# Add 'null' and 'blank', if the 'null_ok' flag was present in the
# table description.
if row.null_ok: # If it's NULL...
extra_params['blank'] = True
extra_params['null'] = True
field_desc = '%s = %s%s' % (
att_name,
# Custom fields will have a dotted path
'' if '.' in field_type else 'models.',
field_type,
)
if field_type.startswith(('ForeignKey(', 'OneToOneField(')):
field_desc += ', models.DO_NOTHING'
if extra_params:
if not field_desc.endswith('('):
field_desc += ', '
field_desc += ', '.join('%s=%r' % (k, v) for k, v in extra_params.items())
field_desc += ')'
if comment_notes:
field_desc += ' # ' + ' '.join(comment_notes)
yield ' %s' % field_desc
is_view = any(info.name == table_name and info.type == 'v' for info in table_info)
is_partition = any(info.name == table_name and info.type == 'p' for info in table_info)
yield from self.get_meta(table_name, constraints, column_to_field_name, is_view, is_partition)
def normalize_col_name(self, col_name, used_column_names, is_relation):
"""
Modify the column name to make it Python-compatible as a field name
"""
field_params = {}
field_notes = []
new_name = col_name.lower()
if new_name != col_name:
field_notes.append('Field name made lowercase.')
if is_relation:
if new_name.endswith('_id'):
new_name = new_name[:-3]
else:
field_params['db_column'] = col_name
new_name, num_repl = re.subn(r'\W', '_', new_name)
if num_repl > 0:
field_notes.append('Field renamed to remove unsuitable characters.')
if new_name.find(LOOKUP_SEP) >= 0:
while new_name.find(LOOKUP_SEP) >= 0:
new_name = new_name.replace(LOOKUP_SEP, '_')
if col_name.lower().find(LOOKUP_SEP) >= 0:
# Only add the comment if the double underscore was in the original name
field_notes.append("Field renamed because it contained more than one '_' in a row.")
if new_name.startswith('_'):
new_name = 'field%s' % new_name
field_notes.append("Field renamed because it started with '_'.")
if new_name.endswith('_'):
new_name = '%sfield' % new_name
field_notes.append("Field renamed because it ended with '_'.")
if keyword.iskeyword(new_name):
new_name += '_field'
field_notes.append('Field renamed because it was a Python reserved word.')
if new_name[0].isdigit():
new_name = 'number_%s' % new_name
field_notes.append("Field renamed because it wasn't a valid Python identifier.")
if new_name in used_column_names:
num = 0
while '%s_%d' % (new_name, num) in used_column_names:
num += 1
new_name = '%s_%d' % (new_name, num)
field_notes.append('Field renamed because of name conflict.')
if col_name != new_name and field_notes:
field_params['db_column'] = col_name
return new_name, field_params, field_notes
def get_field_type(self, connection, table_name, row):
"""
Given the database connection, the table name, and the cursor row
description, this routine will return the given field type name, as
well as any additional keyword parameters and notes for the field.
"""
field_params = {}
field_notes = []
try:
field_type = connection.introspection.get_field_type(row.type_code, row)
except KeyError:
field_type = 'TextField'
field_notes.append('This field type is a guess.')
# Add max_length for all CharFields.
if field_type == 'CharField' and row.internal_size:
field_params['max_length'] = int(row.internal_size)
if field_type in {'CharField', 'TextField'} and row.collation:
field_params['db_collation'] = row.collation
if field_type == 'DecimalField':
if row.precision is None or row.scale is None:
field_notes.append(
'max_digits and decimal_places have been guessed, as this '
'database handles decimal fields as float')
field_params['max_digits'] = row.precision if row.precision is not None else 10
field_params['decimal_places'] = row.scale if row.scale is not None else 5
else:
field_params['max_digits'] = row.precision
field_params['decimal_places'] = row.scale
return field_type, field_params, field_notes
def get_meta(self, table_name, constraints, column_to_field_name, is_view, is_partition):
"""
Return a sequence comprising the lines of code necessary
to construct the inner Meta class for the model corresponding
to the given database table name.
"""
unique_together = []
has_unsupported_constraint = False
for params in constraints.values():
if params['unique']:
columns = params['columns']
if None in columns:
has_unsupported_constraint = True
columns = [x for x in columns if x is not None]
if len(columns) > 1:
unique_together.append(str(tuple(column_to_field_name[c] for c in columns)))
if is_view:
managed_comment = " # Created from a view. Don't remove."
elif is_partition:
managed_comment = " # Created from a partition. Don't remove."
else:
managed_comment = ''
meta = ['']
if has_unsupported_constraint:
meta.append(' # A unique constraint could not be introspected.')
meta += [
' class Meta:',
' managed = False%s' % managed_comment,
' db_table = %r' % table_name
]
if unique_together:
tup = '(' + ', '.join(unique_together) + ',)'
meta += [" unique_together = %s" % tup]
return meta
|
4c12ba2e88279a83af8c55db6ddb7c85c5f19d95f67c0689a2de801d566340bd | import os
import sys
import warnings
from itertools import takewhile
from django.apps import apps
from django.conf import settings
from django.core.management.base import (
BaseCommand, CommandError, no_translations,
)
from django.db import DEFAULT_DB_ALIAS, OperationalError, connections, router
from django.db.migrations import Migration
from django.db.migrations.autodetector import MigrationAutodetector
from django.db.migrations.loader import MigrationLoader
from django.db.migrations.questioner import (
InteractiveMigrationQuestioner, MigrationQuestioner,
NonInteractiveMigrationQuestioner,
)
from django.db.migrations.state import ProjectState
from django.db.migrations.utils import get_migration_name_timestamp
from django.db.migrations.writer import MigrationWriter
class Command(BaseCommand):
help = "Creates new migration(s) for apps."
def add_arguments(self, parser):
parser.add_argument(
'args', metavar='app_label', nargs='*',
help='Specify the app label(s) to create migrations for.',
)
parser.add_argument(
'--dry-run', action='store_true',
help="Just show what migrations would be made; don't actually write them.",
)
parser.add_argument(
'--merge', action='store_true',
help="Enable fixing of migration conflicts.",
)
parser.add_argument(
'--empty', action='store_true',
help="Create an empty migration.",
)
parser.add_argument(
'--noinput', '--no-input', action='store_false', dest='interactive',
help='Tells Django to NOT prompt the user for input of any kind.',
)
parser.add_argument(
'-n', '--name',
help="Use this name for migration file(s).",
)
parser.add_argument(
'--no-header', action='store_false', dest='include_header',
help='Do not add header comments to new migration file(s).',
)
parser.add_argument(
'--check', action='store_true', dest='check_changes',
help='Exit with a non-zero status if model changes are missing migrations.',
)
parser.add_argument(
'--scriptable', action='store_true', dest='scriptable',
help=(
'Divert log output and input prompts to stderr, writing only '
'paths of generated migration files to stdout.'
),
)
@property
def log_output(self):
return self.stderr if self.scriptable else self.stdout
def log(self, msg):
self.log_output.write(msg)
@no_translations
def handle(self, *app_labels, **options):
self.verbosity = options['verbosity']
self.interactive = options['interactive']
self.dry_run = options['dry_run']
self.merge = options['merge']
self.empty = options['empty']
self.migration_name = options['name']
if self.migration_name and not self.migration_name.isidentifier():
raise CommandError('The migration name must be a valid Python identifier.')
self.include_header = options['include_header']
check_changes = options['check_changes']
self.scriptable = options['scriptable']
# If logs and prompts are diverted to stderr, remove the ERROR style.
if self.scriptable:
self.stderr.style_func = None
# Make sure the app they asked for exists
app_labels = set(app_labels)
has_bad_labels = False
for app_label in app_labels:
try:
apps.get_app_config(app_label)
except LookupError as err:
self.stderr.write(str(err))
has_bad_labels = True
if has_bad_labels:
sys.exit(2)
# Load the current graph state. Pass in None for the connection so
# the loader doesn't try to resolve replaced migrations from DB.
loader = MigrationLoader(None, ignore_no_migrations=True)
# Raise an error if any migrations are applied before their dependencies.
consistency_check_labels = {config.label for config in apps.get_app_configs()}
# Non-default databases are only checked if database routers used.
aliases_to_check = connections if settings.DATABASE_ROUTERS else [DEFAULT_DB_ALIAS]
for alias in sorted(aliases_to_check):
connection = connections[alias]
if (connection.settings_dict['ENGINE'] != 'django.db.backends.dummy' and any(
# At least one model must be migrated to the database.
router.allow_migrate(connection.alias, app_label, model_name=model._meta.object_name)
for app_label in consistency_check_labels
for model in apps.get_app_config(app_label).get_models()
)):
try:
loader.check_consistent_history(connection)
except OperationalError as error:
warnings.warn(
"Got an error checking a consistent migration history "
"performed for database connection '%s': %s"
% (alias, error),
RuntimeWarning,
)
# Before anything else, see if there's conflicting apps and drop out
# hard if there are any and they don't want to merge
conflicts = loader.detect_conflicts()
# If app_labels is specified, filter out conflicting migrations for unspecified apps
if app_labels:
conflicts = {
app_label: conflict for app_label, conflict in conflicts.items()
if app_label in app_labels
}
if conflicts and not self.merge:
name_str = "; ".join(
"%s in %s" % (", ".join(names), app)
for app, names in conflicts.items()
)
raise CommandError(
"Conflicting migrations detected; multiple leaf nodes in the "
"migration graph: (%s).\nTo fix them run "
"'python manage.py makemigrations --merge'" % name_str
)
# If they want to merge and there's nothing to merge, then politely exit
if self.merge and not conflicts:
self.log('No conflicts detected to merge.')
return
# If they want to merge and there is something to merge, then
# divert into the merge code
if self.merge and conflicts:
return self.handle_merge(loader, conflicts)
if self.interactive:
questioner = InteractiveMigrationQuestioner(
specified_apps=app_labels,
dry_run=self.dry_run,
prompt_output=self.log_output,
)
else:
questioner = NonInteractiveMigrationQuestioner(
specified_apps=app_labels,
dry_run=self.dry_run,
verbosity=self.verbosity,
log=self.log,
)
# Set up autodetector
autodetector = MigrationAutodetector(
loader.project_state(),
ProjectState.from_apps(apps),
questioner,
)
# If they want to make an empty migration, make one for each app
if self.empty:
if not app_labels:
raise CommandError("You must supply at least one app label when using --empty.")
# Make a fake changes() result we can pass to arrange_for_graph
changes = {
app: [Migration("custom", app)]
for app in app_labels
}
changes = autodetector.arrange_for_graph(
changes=changes,
graph=loader.graph,
migration_name=self.migration_name,
)
self.write_migration_files(changes)
return
# Detect changes
changes = autodetector.changes(
graph=loader.graph,
trim_to_apps=app_labels or None,
convert_apps=app_labels or None,
migration_name=self.migration_name,
)
if not changes:
# No changes? Tell them.
if self.verbosity >= 1:
if app_labels:
if len(app_labels) == 1:
self.log("No changes detected in app '%s'" % app_labels.pop())
else:
self.log("No changes detected in apps '%s'" % ("', '".join(app_labels)))
else:
self.log('No changes detected')
else:
self.write_migration_files(changes)
if check_changes:
sys.exit(1)
def write_migration_files(self, changes):
"""
Take a changes dict and write them out as migration files.
"""
directory_created = {}
for app_label, app_migrations in changes.items():
if self.verbosity >= 1:
self.log(self.style.MIGRATE_HEADING("Migrations for '%s':" % app_label))
for migration in app_migrations:
# Describe the migration
writer = MigrationWriter(migration, self.include_header)
if self.verbosity >= 1:
# Display a relative path if it's below the current working
# directory, or an absolute path otherwise.
try:
migration_string = os.path.relpath(writer.path)
except ValueError:
migration_string = writer.path
if migration_string.startswith('..'):
migration_string = writer.path
self.log(' %s\n' % self.style.MIGRATE_LABEL(migration_string))
for operation in migration.operations:
self.log(' - %s' % operation.describe())
if self.scriptable:
self.stdout.write(migration_string)
if not self.dry_run:
# Write the migrations file to the disk.
migrations_directory = os.path.dirname(writer.path)
if not directory_created.get(app_label):
os.makedirs(migrations_directory, exist_ok=True)
init_path = os.path.join(migrations_directory, "__init__.py")
if not os.path.isfile(init_path):
open(init_path, "w").close()
# We just do this once per app
directory_created[app_label] = True
migration_string = writer.as_string()
with open(writer.path, "w", encoding='utf-8') as fh:
fh.write(migration_string)
elif self.verbosity == 3:
# Alternatively, makemigrations --dry-run --verbosity 3
# will log the migrations rather than saving the file to
# the disk.
self.log(self.style.MIGRATE_HEADING(
"Full migrations file '%s':" % writer.filename
))
self.log(writer.as_string())
def handle_merge(self, loader, conflicts):
"""
Handles merging together conflicted migrations interactively,
if it's safe; otherwise, advises on how to fix it.
"""
if self.interactive:
questioner = InteractiveMigrationQuestioner(prompt_output=self.log_output)
else:
questioner = MigrationQuestioner(defaults={'ask_merge': True})
for app_label, migration_names in conflicts.items():
# Grab out the migrations in question, and work out their
# common ancestor.
merge_migrations = []
for migration_name in migration_names:
migration = loader.get_migration(app_label, migration_name)
migration.ancestry = [
mig for mig in loader.graph.forwards_plan((app_label, migration_name))
if mig[0] == migration.app_label
]
merge_migrations.append(migration)
def all_items_equal(seq):
return all(item == seq[0] for item in seq[1:])
merge_migrations_generations = zip(*(m.ancestry for m in merge_migrations))
common_ancestor_count = sum(1 for common_ancestor_generation
in takewhile(all_items_equal, merge_migrations_generations))
if not common_ancestor_count:
raise ValueError("Could not find common ancestor of %s" % migration_names)
# Now work out the operations along each divergent branch
for migration in merge_migrations:
migration.branch = migration.ancestry[common_ancestor_count:]
migrations_ops = (loader.get_migration(node_app, node_name).operations
for node_app, node_name in migration.branch)
migration.merged_operations = sum(migrations_ops, [])
# In future, this could use some of the Optimizer code
# (can_optimize_through) to automatically see if they're
# mergeable. For now, we always just prompt the user.
if self.verbosity > 0:
self.log(self.style.MIGRATE_HEADING('Merging %s' % app_label))
for migration in merge_migrations:
self.log(self.style.MIGRATE_LABEL(' Branch %s' % migration.name))
for operation in migration.merged_operations:
self.log(' - %s' % operation.describe())
if questioner.ask_merge(app_label):
# If they still want to merge it, then write out an empty
# file depending on the migrations needing merging.
numbers = [
MigrationAutodetector.parse_number(migration.name)
for migration in merge_migrations
]
try:
biggest_number = max(x for x in numbers if x is not None)
except ValueError:
biggest_number = 1
subclass = type("Migration", (Migration,), {
"dependencies": [(app_label, migration.name) for migration in merge_migrations],
})
parts = ['%04i' % (biggest_number + 1)]
if self.migration_name:
parts.append(self.migration_name)
else:
parts.append('merge')
leaf_names = '_'.join(sorted(migration.name for migration in merge_migrations))
if len(leaf_names) > 47:
parts.append(get_migration_name_timestamp())
else:
parts.append(leaf_names)
migration_name = '_'.join(parts)
new_migration = subclass(migration_name, app_label)
writer = MigrationWriter(new_migration, self.include_header)
if not self.dry_run:
# Write the merge migrations file to the disk
with open(writer.path, "w", encoding='utf-8') as fh:
fh.write(writer.as_string())
if self.verbosity > 0:
self.log('\nCreated new merge migration %s' % writer.path)
if self.scriptable:
self.stdout.write(writer.path)
elif self.verbosity == 3:
# Alternatively, makemigrations --merge --dry-run --verbosity 3
# will log the merge migrations rather than saving the file
# to the disk.
self.log(self.style.MIGRATE_HEADING(
"Full merge migrations file '%s':" % writer.filename
))
self.log(writer.as_string())
|
181025f572892699dd3b4cf7f034153af81f5693203983672526da1654ed4c6d | import os
import select
import sys
import traceback
from django.core.management import BaseCommand, CommandError
from django.utils.datastructures import OrderedSet
class Command(BaseCommand):
help = (
"Runs a Python interactive interpreter. Tries to use IPython or "
"bpython, if one of them is available. Any standard input is executed "
"as code."
)
requires_system_checks = []
shells = ['ipython', 'bpython', 'python']
def add_arguments(self, parser):
parser.add_argument(
'--no-startup', action='store_true',
help='When using plain Python, ignore the PYTHONSTARTUP environment variable and ~/.pythonrc.py script.',
)
parser.add_argument(
'-i', '--interface', choices=self.shells,
help='Specify an interactive interpreter interface. Available options: "ipython", "bpython", and "python"',
)
parser.add_argument(
'-c', '--command',
help='Instead of opening an interactive shell, run a command as Django and exit.',
)
def ipython(self, options):
from IPython import start_ipython
start_ipython(argv=[])
def bpython(self, options):
import bpython
bpython.embed()
def python(self, options):
import code
# Set up a dictionary to serve as the environment for the shell.
imported_objects = {}
# We want to honor both $PYTHONSTARTUP and .pythonrc.py, so follow system
# conventions and get $PYTHONSTARTUP first then .pythonrc.py.
if not options['no_startup']:
for pythonrc in OrderedSet([os.environ.get("PYTHONSTARTUP"), os.path.expanduser('~/.pythonrc.py')]):
if not pythonrc:
continue
if not os.path.isfile(pythonrc):
continue
with open(pythonrc) as handle:
pythonrc_code = handle.read()
# Match the behavior of the cpython shell where an error in
# PYTHONSTARTUP prints an exception and continues.
try:
exec(compile(pythonrc_code, pythonrc, 'exec'), imported_objects)
except Exception:
traceback.print_exc()
# By default, this will set up readline to do tab completion and to read and
# write history to the .python_history file, but this can be overridden by
# $PYTHONSTARTUP or ~/.pythonrc.py.
try:
hook = sys.__interactivehook__
except AttributeError:
# Match the behavior of the cpython shell where a missing
# sys.__interactivehook__ is ignored.
pass
else:
try:
hook()
except Exception:
# Match the behavior of the cpython shell where an error in
# sys.__interactivehook__ prints a warning and the exception
# and continues.
print('Failed calling sys.__interactivehook__')
traceback.print_exc()
# Set up tab completion for objects imported by $PYTHONSTARTUP or
# ~/.pythonrc.py.
try:
import readline
import rlcompleter
readline.set_completer(rlcompleter.Completer(imported_objects).complete)
except ImportError:
pass
# Start the interactive interpreter.
code.interact(local=imported_objects)
def handle(self, **options):
# Execute the command and exit.
if options['command']:
exec(options['command'], globals())
return
# Execute stdin if it has anything to read and exit.
# Not supported on Windows due to select.select() limitations.
if sys.platform != 'win32' and not sys.stdin.isatty() and select.select([sys.stdin], [], [], 0)[0]:
exec(sys.stdin.read(), globals())
return
available_shells = [options['interface']] if options['interface'] else self.shells
for shell in available_shells:
try:
return getattr(self, shell)(options)
except ImportError:
pass
raise CommandError("Couldn't import {} interface.".format(shell))
|
cc5b96b06fbb3db8d60c2bb929321f9b7fc4ddf1482140960027ac74b4282982 | "File-based cache backend"
import glob
import os
import pickle
import random
import tempfile
import time
import zlib
from django.core.cache.backends.base import DEFAULT_TIMEOUT, BaseCache
from django.core.files import locks
from django.core.files.move import file_move_safe
from django.utils.crypto import md5
class FileBasedCache(BaseCache):
cache_suffix = '.djcache'
pickle_protocol = pickle.HIGHEST_PROTOCOL
def __init__(self, dir, params):
super().__init__(params)
self._dir = os.path.abspath(dir)
self._createdir()
def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
if self.has_key(key, version):
return False
self.set(key, value, timeout, version)
return True
def get(self, key, default=None, version=None):
fname = self._key_to_file(key, version)
try:
with open(fname, 'rb') as f:
if not self._is_expired(f):
return pickle.loads(zlib.decompress(f.read()))
except FileNotFoundError:
pass
return default
def _write_content(self, file, timeout, value):
expiry = self.get_backend_timeout(timeout)
file.write(pickle.dumps(expiry, self.pickle_protocol))
file.write(zlib.compress(pickle.dumps(value, self.pickle_protocol)))
def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
self._createdir() # Cache dir can be deleted at any time.
fname = self._key_to_file(key, version)
self._cull() # make some room if necessary
fd, tmp_path = tempfile.mkstemp(dir=self._dir)
renamed = False
try:
with open(fd, 'wb') as f:
self._write_content(f, timeout, value)
file_move_safe(tmp_path, fname, allow_overwrite=True)
renamed = True
finally:
if not renamed:
os.remove(tmp_path)
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
try:
with open(self._key_to_file(key, version), 'r+b') as f:
try:
locks.lock(f, locks.LOCK_EX)
if self._is_expired(f):
return False
else:
previous_value = pickle.loads(zlib.decompress(f.read()))
f.seek(0)
self._write_content(f, timeout, previous_value)
return True
finally:
locks.unlock(f)
except FileNotFoundError:
return False
def delete(self, key, version=None):
return self._delete(self._key_to_file(key, version))
def _delete(self, fname):
if not fname.startswith(self._dir) or not os.path.exists(fname):
return False
try:
os.remove(fname)
except FileNotFoundError:
# The file may have been removed by another process.
return False
return True
def has_key(self, key, version=None):
fname = self._key_to_file(key, version)
if os.path.exists(fname):
with open(fname, 'rb') as f:
return not self._is_expired(f)
return False
def _cull(self):
"""
Remove random cache entries if max_entries is reached at a ratio
of num_entries / cull_frequency. A value of 0 for CULL_FREQUENCY means
that the entire cache will be purged.
"""
filelist = self._list_cache_files()
num_entries = len(filelist)
if num_entries < self._max_entries:
return # return early if no culling is required
if self._cull_frequency == 0:
return self.clear() # Clear the cache when CULL_FREQUENCY = 0
# Delete a random selection of entries
filelist = random.sample(filelist,
int(num_entries / self._cull_frequency))
for fname in filelist:
self._delete(fname)
def _createdir(self):
# Set the umask because os.makedirs() doesn't apply the "mode" argument
# to intermediate-level directories.
old_umask = os.umask(0o077)
try:
os.makedirs(self._dir, 0o700, exist_ok=True)
finally:
os.umask(old_umask)
def _key_to_file(self, key, version=None):
"""
Convert a key into a cache file path. Basically this is the
root cache path joined with the md5sum of the key and a suffix.
"""
key = self.make_and_validate_key(key, version=version)
return os.path.join(self._dir, ''.join([
md5(key.encode(), usedforsecurity=False).hexdigest(),
self.cache_suffix,
]))
def clear(self):
"""
Remove all the cache files.
"""
for fname in self._list_cache_files():
self._delete(fname)
def _is_expired(self, f):
"""
Take an open cache file `f` and delete it if it's expired.
"""
try:
exp = pickle.load(f)
except EOFError:
exp = 0 # An empty file is considered expired.
if exp is not None and exp < time.time():
f.close() # On Windows a file has to be closed before deleting
self._delete(f.name)
return True
return False
def _list_cache_files(self):
"""
Get a list of paths to all the cache files. These are all the files
in the root cache dir that end on the cache_suffix.
"""
return [
os.path.join(self._dir, fname)
for fname in glob.glob1(self._dir, '*%s' % self.cache_suffix)
]
|
a3812eed37283a426bc5dfd15ef14fd5942ea839bc4a54dc0cdbe78137c2a06f | "Memcached cache backend"
import re
import time
from django.core.cache.backends.base import (
DEFAULT_TIMEOUT, BaseCache, InvalidCacheKey, memcache_key_warnings,
)
from django.utils.functional import cached_property
class BaseMemcachedCache(BaseCache):
def __init__(self, server, params, library, value_not_found_exception):
super().__init__(params)
if isinstance(server, str):
self._servers = re.split('[;,]', server)
else:
self._servers = server
# Exception type raised by the underlying client library for a
# nonexistent key.
self.LibraryValueNotFoundException = value_not_found_exception
self._lib = library
self._class = library.Client
self._options = params.get('OPTIONS') or {}
@property
def client_servers(self):
return self._servers
@cached_property
def _cache(self):
"""
Implement transparent thread-safe access to a memcached client.
"""
return self._class(self.client_servers, **self._options)
def get_backend_timeout(self, timeout=DEFAULT_TIMEOUT):
"""
Memcached deals with long (> 30 days) timeouts in a special
way. Call this function to obtain a safe value for your timeout.
"""
if timeout == DEFAULT_TIMEOUT:
timeout = self.default_timeout
if timeout is None:
# Using 0 in memcache sets a non-expiring timeout.
return 0
elif int(timeout) == 0:
# Other cache backends treat 0 as set-and-expire. To achieve this
# in memcache backends, a negative timeout must be passed.
timeout = -1
if timeout > 2592000: # 60*60*24*30, 30 days
# See https://github.com/memcached/memcached/wiki/Programming#expiration
# "Expiration times can be set from 0, meaning "never expire", to
# 30 days. Any time higher than 30 days is interpreted as a Unix
# timestamp date. If you want to expire an object on January 1st of
# next year, this is how you do that."
#
# This means that we have to switch to absolute timestamps.
timeout += int(time.time())
return int(timeout)
def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.add(key, value, self.get_backend_timeout(timeout))
def get(self, key, default=None, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.get(key, default)
def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
if not self._cache.set(key, value, self.get_backend_timeout(timeout)):
# make sure the key doesn't keep its old value in case of failure to set (memcached's 1MB limit)
self._cache.delete(key)
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
return bool(self._cache.touch(key, self.get_backend_timeout(timeout)))
def delete(self, key, version=None):
key = self.make_and_validate_key(key, version=version)
return bool(self._cache.delete(key))
def get_many(self, keys, version=None):
key_map = {self.make_and_validate_key(key, version=version): key for key in keys}
ret = self._cache.get_multi(key_map.keys())
return {key_map[k]: v for k, v in ret.items()}
def close(self, **kwargs):
# Many clients don't clean up connections properly.
self._cache.disconnect_all()
def incr(self, key, delta=1, version=None):
key = self.make_and_validate_key(key, version=version)
try:
# Memcached doesn't support negative delta.
if delta < 0:
val = self._cache.decr(key, -delta)
else:
val = self._cache.incr(key, delta)
# Normalize an exception raised by the underlying client library to
# ValueError in the event of a nonexistent key when calling
# incr()/decr().
except self.LibraryValueNotFoundException:
val = None
if val is None:
raise ValueError("Key '%s' not found" % key)
return val
def set_many(self, data, timeout=DEFAULT_TIMEOUT, version=None):
safe_data = {}
original_keys = {}
for key, value in data.items():
safe_key = self.make_and_validate_key(key, version=version)
safe_data[safe_key] = value
original_keys[safe_key] = key
failed_keys = self._cache.set_multi(safe_data, self.get_backend_timeout(timeout))
return [original_keys[k] for k in failed_keys]
def delete_many(self, keys, version=None):
keys = [self.make_and_validate_key(key, version=version) for key in keys]
self._cache.delete_multi(keys)
def clear(self):
self._cache.flush_all()
def validate_key(self, key):
for warning in memcache_key_warnings(key):
raise InvalidCacheKey(warning)
class PyLibMCCache(BaseMemcachedCache):
"An implementation of a cache binding using pylibmc"
def __init__(self, server, params):
import pylibmc
super().__init__(server, params, library=pylibmc, value_not_found_exception=pylibmc.NotFound)
@property
def client_servers(self):
output = []
for server in self._servers:
output.append(server[5:] if server.startswith('unix:') else server)
return output
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
if timeout == 0:
return self._cache.delete(key)
return self._cache.touch(key, self.get_backend_timeout(timeout))
def close(self, **kwargs):
# libmemcached manages its own connections. Don't call disconnect_all()
# as it resets the failover state and creates unnecessary reconnects.
pass
class PyMemcacheCache(BaseMemcachedCache):
"""An implementation of a cache binding using pymemcache."""
def __init__(self, server, params):
import pymemcache.serde
super().__init__(server, params, library=pymemcache, value_not_found_exception=KeyError)
self._class = self._lib.HashClient
self._options = {
'allow_unicode_keys': True,
'default_noreply': False,
'serde': pymemcache.serde.pickle_serde,
**self._options,
}
|
7a68b0a7b7160032a9bfc2072c3d953444346c2a221902486530ec775dfe95cb | "Database cache backend."
import base64
import pickle
from datetime import datetime
from django.conf import settings
from django.core.cache.backends.base import DEFAULT_TIMEOUT, BaseCache
from django.db import DatabaseError, connections, models, router, transaction
from django.utils import timezone
class Options:
"""A class that will quack like a Django model _meta class.
This allows cache operations to be controlled by the router
"""
def __init__(self, table):
self.db_table = table
self.app_label = 'django_cache'
self.model_name = 'cacheentry'
self.verbose_name = 'cache entry'
self.verbose_name_plural = 'cache entries'
self.object_name = 'CacheEntry'
self.abstract = False
self.managed = True
self.proxy = False
self.swapped = False
class BaseDatabaseCache(BaseCache):
def __init__(self, table, params):
super().__init__(params)
self._table = table
class CacheEntry:
_meta = Options(table)
self.cache_model_class = CacheEntry
class DatabaseCache(BaseDatabaseCache):
# This class uses cursors provided by the database connection. This means
# it reads expiration values as aware or naive datetimes, depending on the
# value of USE_TZ and whether the database supports time zones. The ORM's
# conversion and adaptation infrastructure is then used to avoid comparing
# aware and naive datetimes accidentally.
pickle_protocol = pickle.HIGHEST_PROTOCOL
def get(self, key, default=None, version=None):
return self.get_many([key], version).get(key, default)
def get_many(self, keys, version=None):
if not keys:
return {}
key_map = {self.make_and_validate_key(key, version=version): key for key in keys}
db = router.db_for_read(self.cache_model_class)
connection = connections[db]
quote_name = connection.ops.quote_name
table = quote_name(self._table)
with connection.cursor() as cursor:
cursor.execute(
'SELECT %s, %s, %s FROM %s WHERE %s IN (%s)' % (
quote_name('cache_key'),
quote_name('value'),
quote_name('expires'),
table,
quote_name('cache_key'),
', '.join(['%s'] * len(key_map)),
),
list(key_map),
)
rows = cursor.fetchall()
result = {}
expired_keys = []
expression = models.Expression(output_field=models.DateTimeField())
converters = (connection.ops.get_db_converters(expression) + expression.get_db_converters(connection))
for key, value, expires in rows:
for converter in converters:
expires = converter(expires, expression, connection)
if expires < timezone.now():
expired_keys.append(key)
else:
value = connection.ops.process_clob(value)
value = pickle.loads(base64.b64decode(value.encode()))
result[key_map.get(key)] = value
self._base_delete_many(expired_keys)
return result
def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
self._base_set('set', key, value, timeout)
def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
return self._base_set('add', key, value, timeout)
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
return self._base_set('touch', key, None, timeout)
def _base_set(self, mode, key, value, timeout=DEFAULT_TIMEOUT):
timeout = self.get_backend_timeout(timeout)
db = router.db_for_write(self.cache_model_class)
connection = connections[db]
quote_name = connection.ops.quote_name
table = quote_name(self._table)
with connection.cursor() as cursor:
cursor.execute("SELECT COUNT(*) FROM %s" % table)
num = cursor.fetchone()[0]
now = timezone.now()
now = now.replace(microsecond=0)
if timeout is None:
exp = datetime.max
else:
tz = timezone.utc if settings.USE_TZ else None
exp = datetime.fromtimestamp(timeout, tz=tz)
exp = exp.replace(microsecond=0)
if num > self._max_entries:
self._cull(db, cursor, now, num)
pickled = pickle.dumps(value, self.pickle_protocol)
# The DB column is expecting a string, so make sure the value is a
# string, not bytes. Refs #19274.
b64encoded = base64.b64encode(pickled).decode('latin1')
try:
# Note: typecasting for datetimes is needed by some 3rd party
# database backends. All core backends work without typecasting,
# so be careful about changes here - test suite will NOT pick
# regressions.
with transaction.atomic(using=db):
cursor.execute(
'SELECT %s, %s FROM %s WHERE %s = %%s' % (
quote_name('cache_key'),
quote_name('expires'),
table,
quote_name('cache_key'),
),
[key]
)
result = cursor.fetchone()
if result:
current_expires = result[1]
expression = models.Expression(output_field=models.DateTimeField())
for converter in (connection.ops.get_db_converters(expression) +
expression.get_db_converters(connection)):
current_expires = converter(current_expires, expression, connection)
exp = connection.ops.adapt_datetimefield_value(exp)
if result and mode == 'touch':
cursor.execute(
'UPDATE %s SET %s = %%s WHERE %s = %%s' % (
table,
quote_name('expires'),
quote_name('cache_key')
),
[exp, key]
)
elif result and (mode == 'set' or (mode == 'add' and current_expires < now)):
cursor.execute(
'UPDATE %s SET %s = %%s, %s = %%s WHERE %s = %%s' % (
table,
quote_name('value'),
quote_name('expires'),
quote_name('cache_key'),
),
[b64encoded, exp, key]
)
elif mode != 'touch':
cursor.execute(
'INSERT INTO %s (%s, %s, %s) VALUES (%%s, %%s, %%s)' % (
table,
quote_name('cache_key'),
quote_name('value'),
quote_name('expires'),
),
[key, b64encoded, exp]
)
else:
return False # touch failed.
except DatabaseError:
# To be threadsafe, updates/inserts are allowed to fail silently
return False
else:
return True
def delete(self, key, version=None):
key = self.make_and_validate_key(key, version=version)
return self._base_delete_many([key])
def delete_many(self, keys, version=None):
keys = [self.make_and_validate_key(key, version=version) for key in keys]
self._base_delete_many(keys)
def _base_delete_many(self, keys):
if not keys:
return False
db = router.db_for_write(self.cache_model_class)
connection = connections[db]
quote_name = connection.ops.quote_name
table = quote_name(self._table)
with connection.cursor() as cursor:
cursor.execute(
'DELETE FROM %s WHERE %s IN (%s)' % (
table,
quote_name('cache_key'),
', '.join(['%s'] * len(keys)),
),
keys,
)
return bool(cursor.rowcount)
def has_key(self, key, version=None):
key = self.make_and_validate_key(key, version=version)
db = router.db_for_read(self.cache_model_class)
connection = connections[db]
quote_name = connection.ops.quote_name
now = timezone.now().replace(microsecond=0, tzinfo=None)
with connection.cursor() as cursor:
cursor.execute(
'SELECT %s FROM %s WHERE %s = %%s and %s > %%s' % (
quote_name('cache_key'),
quote_name(self._table),
quote_name('cache_key'),
quote_name('expires'),
),
[key, connection.ops.adapt_datetimefield_value(now)]
)
return cursor.fetchone() is not None
def _cull(self, db, cursor, now, num):
if self._cull_frequency == 0:
self.clear()
else:
connection = connections[db]
table = connection.ops.quote_name(self._table)
cursor.execute('DELETE FROM %s WHERE %s < %%s' % (
table,
connection.ops.quote_name('expires'),
), [connection.ops.adapt_datetimefield_value(now)])
deleted_count = cursor.rowcount
remaining_num = num - deleted_count
if remaining_num > self._max_entries:
cull_num = remaining_num // self._cull_frequency
cursor.execute(
connection.ops.cache_key_culling_sql() % table,
[cull_num])
last_cache_key = cursor.fetchone()
if last_cache_key:
cursor.execute(
'DELETE FROM %s WHERE %s < %%s' % (
table,
connection.ops.quote_name('cache_key'),
),
[last_cache_key[0]],
)
def clear(self):
db = router.db_for_write(self.cache_model_class)
connection = connections[db]
table = connection.ops.quote_name(self._table)
with connection.cursor() as cursor:
cursor.execute('DELETE FROM %s' % table)
|
610652b0476df3ed775a7ee3d5c57c8547dc1ff0b49bc0a21726089d4200d68b | """Redis cache backend."""
import pickle
import random
import re
from django.core.cache.backends.base import DEFAULT_TIMEOUT, BaseCache
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
class RedisSerializer:
def __init__(self, protocol=None):
self.protocol = pickle.HIGHEST_PROTOCOL if protocol is None else protocol
def dumps(self, obj):
# Only skip pickling for integers, a int subclasses as bool should be
# pickled.
if type(obj) is int:
return obj
return pickle.dumps(obj, self.protocol)
def loads(self, data):
try:
return int(data)
except ValueError:
return pickle.loads(data)
class RedisCacheClient:
def __init__(
self,
servers,
serializer=None,
db=None,
pool_class=None,
parser_class=None,
):
import redis
self._lib = redis
self._servers = servers
self._pools = {}
self._client = self._lib.Redis
if isinstance(pool_class, str):
pool_class = import_string(pool_class)
self._pool_class = pool_class or self._lib.ConnectionPool
if isinstance(serializer, str):
serializer = import_string(serializer)
if callable(serializer):
serializer = serializer()
self._serializer = serializer or RedisSerializer()
if isinstance(parser_class, str):
parser_class = import_string(parser_class)
parser_class = parser_class or self._lib.connection.DefaultParser
self._pool_options = {'parser_class': parser_class, 'db': db}
def _get_connection_pool_index(self, write):
# Write to the first server. Read from other servers if there are more,
# otherwise read from the first server.
if write or len(self._servers) == 1:
return 0
return random.randint(1, len(self._servers) - 1)
def _get_connection_pool(self, write):
index = self._get_connection_pool_index(write)
if index not in self._pools:
self._pools[index] = self._pool_class.from_url(
self._servers[index], **self._pool_options,
)
return self._pools[index]
def get_client(self, key=None, *, write=False):
# key is used so that the method signature remains the same and custom
# cache client can be implemented which might require the key to select
# the server, e.g. sharding.
pool = self._get_connection_pool(write)
return self._client(connection_pool=pool)
def add(self, key, value, timeout):
client = self.get_client(key, write=True)
value = self._serializer.dumps(value)
if timeout == 0:
if ret := bool(client.set(key, value, nx=True)):
client.delete(key)
return ret
else:
return bool(client.set(key, value, ex=timeout, nx=True))
def get(self, key, default):
client = self.get_client(key)
value = client.get(key)
return default if value is None else self._serializer.loads(value)
def set(self, key, value, timeout):
client = self.get_client(key, write=True)
value = self._serializer.dumps(value)
if timeout == 0:
client.delete(key)
else:
client.set(key, value, ex=timeout)
def touch(self, key, timeout):
client = self.get_client(key, write=True)
if timeout is None:
return bool(client.persist(key))
else:
return bool(client.expire(key, timeout))
def delete(self, key):
client = self.get_client(key, write=True)
return bool(client.delete(key))
def get_many(self, keys):
client = self.get_client(None)
ret = client.mget(keys)
return {
k: self._serializer.loads(v) for k, v in zip(keys, ret) if v is not None
}
def has_key(self, key):
client = self.get_client(key)
return bool(client.exists(key))
def incr(self, key, delta):
client = self.get_client(key)
if not client.exists(key):
raise ValueError("Key '%s' not found." % key)
return client.incr(key, delta)
def set_many(self, data, timeout):
client = self.get_client(None, write=True)
pipeline = client.pipeline()
pipeline.mset({k: self._serializer.dumps(v) for k, v in data.items()})
if timeout is not None:
# Setting timeout for each key as redis does not support timeout
# with mset().
for key in data:
pipeline.expire(key, timeout)
pipeline.execute()
def delete_many(self, keys):
client = self.get_client(None, write=True)
client.delete(*keys)
def clear(self):
client = self.get_client(None, write=True)
return bool(client.flushdb())
class RedisCache(BaseCache):
def __init__(self, server, params):
super().__init__(params)
if isinstance(server, str):
self._servers = re.split('[;,]', server)
else:
self._servers = server
self._class = RedisCacheClient
self._options = params.get('OPTIONS', {})
@cached_property
def _cache(self):
return self._class(self._servers, **self._options)
def get_backend_timeout(self, timeout=DEFAULT_TIMEOUT):
if timeout == DEFAULT_TIMEOUT:
timeout = self.default_timeout
# The key will be made persistent if None used as a timeout.
# Non-positive values will cause the key to be deleted.
return None if timeout is None else max(0, int(timeout))
def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.add(key, value, self.get_backend_timeout(timeout))
def get(self, key, default=None, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.get(key, default)
def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
self._cache.set(key, value, self.get_backend_timeout(timeout))
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.touch(key, self.get_backend_timeout(timeout))
def delete(self, key, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.delete(key)
def get_many(self, keys, version=None):
key_map = {self.make_and_validate_key(key, version=version): key for key in keys}
ret = self._cache.get_many(key_map.keys())
return {key_map[k]: v for k, v in ret.items()}
def has_key(self, key, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.has_key(key)
def incr(self, key, delta=1, version=None):
key = self.make_and_validate_key(key, version=version)
return self._cache.incr(key, delta)
def set_many(self, data, timeout=DEFAULT_TIMEOUT, version=None):
safe_data = {}
for key, value in data.items():
key = self.make_and_validate_key(key, version=version)
safe_data[key] = value
self._cache.set_many(safe_data, self.get_backend_timeout(timeout))
return []
def delete_many(self, keys, version=None):
safe_keys = []
for key in keys:
key = self.make_and_validate_key(key, version=version)
safe_keys.append(key)
self._cache.delete_many(safe_keys)
def clear(self):
return self._cache.clear()
|
0eeb6ebe93856a89a510c6ca676e3005df91d9ee01af5441172b5a7241dda1e6 | "Base Cache class."
import time
import warnings
from asgiref.sync import sync_to_async
from django.core.exceptions import ImproperlyConfigured
from django.utils.module_loading import import_string
class InvalidCacheBackendError(ImproperlyConfigured):
pass
class CacheKeyWarning(RuntimeWarning):
pass
class InvalidCacheKey(ValueError):
pass
# Stub class to ensure not passing in a `timeout` argument results in
# the default timeout
DEFAULT_TIMEOUT = object()
# Memcached does not accept keys longer than this.
MEMCACHE_MAX_KEY_LENGTH = 250
def default_key_func(key, key_prefix, version):
"""
Default function to generate keys.
Construct the key used by all other methods. By default, prepend
the `key_prefix`. KEY_FUNCTION can be used to specify an alternate
function with custom key making behavior.
"""
return '%s:%s:%s' % (key_prefix, version, key)
def get_key_func(key_func):
"""
Function to decide which key function to use.
Default to ``default_key_func``.
"""
if key_func is not None:
if callable(key_func):
return key_func
else:
return import_string(key_func)
return default_key_func
class BaseCache:
_missing_key = object()
def __init__(self, params):
timeout = params.get('timeout', params.get('TIMEOUT', 300))
if timeout is not None:
try:
timeout = int(timeout)
except (ValueError, TypeError):
timeout = 300
self.default_timeout = timeout
options = params.get('OPTIONS', {})
max_entries = params.get('max_entries', options.get('MAX_ENTRIES', 300))
try:
self._max_entries = int(max_entries)
except (ValueError, TypeError):
self._max_entries = 300
cull_frequency = params.get('cull_frequency', options.get('CULL_FREQUENCY', 3))
try:
self._cull_frequency = int(cull_frequency)
except (ValueError, TypeError):
self._cull_frequency = 3
self.key_prefix = params.get('KEY_PREFIX', '')
self.version = params.get('VERSION', 1)
self.key_func = get_key_func(params.get('KEY_FUNCTION'))
def get_backend_timeout(self, timeout=DEFAULT_TIMEOUT):
"""
Return the timeout value usable by this backend based upon the provided
timeout.
"""
if timeout == DEFAULT_TIMEOUT:
timeout = self.default_timeout
elif timeout == 0:
# ticket 21147 - avoid time.time() related precision issues
timeout = -1
return None if timeout is None else time.time() + timeout
def make_key(self, key, version=None):
"""
Construct the key used by all other methods. By default, use the
key_func to generate a key (which, by default, prepends the
`key_prefix' and 'version'). A different key function can be provided
at the time of cache construction; alternatively, you can subclass the
cache backend to provide custom key making behavior.
"""
if version is None:
version = self.version
return self.key_func(key, self.key_prefix, version)
def validate_key(self, key):
"""
Warn about keys that would not be portable to the memcached
backend. This encourages (but does not force) writing backend-portable
cache code.
"""
for warning in memcache_key_warnings(key):
warnings.warn(warning, CacheKeyWarning)
def make_and_validate_key(self, key, version=None):
"""Helper to make and validate keys."""
key = self.make_key(key, version=version)
self.validate_key(key)
return key
def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
"""
Set a value in the cache if the key does not already exist. If
timeout is given, use that timeout for the key; otherwise use the
default cache timeout.
Return True if the value was stored, False otherwise.
"""
raise NotImplementedError('subclasses of BaseCache must provide an add() method')
async def aadd(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
return await sync_to_async(self.add, thread_sensitive=True)(key, value, timeout, version)
def get(self, key, default=None, version=None):
"""
Fetch a given key from the cache. If the key does not exist, return
default, which itself defaults to None.
"""
raise NotImplementedError('subclasses of BaseCache must provide a get() method')
async def aget(self, key, default=None, version=None):
return await sync_to_async(self.get, thread_sensitive=True)(key, default, version)
def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
"""
Set a value in the cache. If timeout is given, use that timeout for the
key; otherwise use the default cache timeout.
"""
raise NotImplementedError('subclasses of BaseCache must provide a set() method')
async def aset(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
return await sync_to_async(self.set, thread_sensitive=True)(key, value, timeout, version)
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
"""
Update the key's expiry time using timeout. Return True if successful
or False if the key does not exist.
"""
raise NotImplementedError('subclasses of BaseCache must provide a touch() method')
async def atouch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
return await sync_to_async(self.touch, thread_sensitive=True)(key, timeout, version)
def delete(self, key, version=None):
"""
Delete a key from the cache and return whether it succeeded, failing
silently.
"""
raise NotImplementedError('subclasses of BaseCache must provide a delete() method')
async def adelete(self, key, version=None):
return await sync_to_async(self.delete, thread_sensitive=True)(key, version)
def get_many(self, keys, version=None):
"""
Fetch a bunch of keys from the cache. For certain backends (memcached,
pgsql) this can be *much* faster when fetching multiple values.
Return a dict mapping each key in keys to its value. If the given
key is missing, it will be missing from the response dict.
"""
d = {}
for k in keys:
val = self.get(k, self._missing_key, version=version)
if val is not self._missing_key:
d[k] = val
return d
async def aget_many(self, keys, version=None):
"""See get_many()."""
d = {}
for k in keys:
val = await self.aget(k, self._missing_key, version=version)
if val is not self._missing_key:
d[k] = val
return d
def get_or_set(self, key, default, timeout=DEFAULT_TIMEOUT, version=None):
"""
Fetch a given key from the cache. If the key does not exist,
add the key and set it to the default value. The default value can
also be any callable. If timeout is given, use that timeout for the
key; otherwise use the default cache timeout.
Return the value of the key stored or retrieved.
"""
val = self.get(key, self._missing_key, version=version)
if val is self._missing_key:
if callable(default):
default = default()
self.add(key, default, timeout=timeout, version=version)
# Fetch the value again to avoid a race condition if another caller
# added a value between the first get() and the add() above.
return self.get(key, default, version=version)
return val
async def aget_or_set(self, key, default, timeout=DEFAULT_TIMEOUT, version=None):
"""See get_or_set()."""
val = await self.aget(key, self._missing_key, version=version)
if val is self._missing_key:
if callable(default):
default = default()
await self.aadd(key, default, timeout=timeout, version=version)
# Fetch the value again to avoid a race condition if another caller
# added a value between the first aget() and the aadd() above.
return await self.aget(key, default, version=version)
return val
def has_key(self, key, version=None):
"""
Return True if the key is in the cache and has not expired.
"""
return self.get(key, self._missing_key, version=version) is not self._missing_key
async def ahas_key(self, key, version=None):
return (
await self.aget(key, self._missing_key, version=version)
is not self._missing_key
)
def incr(self, key, delta=1, version=None):
"""
Add delta to value in the cache. If the key does not exist, raise a
ValueError exception.
"""
value = self.get(key, self._missing_key, version=version)
if value is self._missing_key:
raise ValueError("Key '%s' not found" % key)
new_value = value + delta
self.set(key, new_value, version=version)
return new_value
async def aincr(self, key, delta=1, version=None):
"""See incr()."""
value = await self.aget(key, self._missing_key, version=version)
if value is self._missing_key:
raise ValueError("Key '%s' not found" % key)
new_value = value + delta
await self.aset(key, new_value, version=version)
return new_value
def decr(self, key, delta=1, version=None):
"""
Subtract delta from value in the cache. If the key does not exist, raise
a ValueError exception.
"""
return self.incr(key, -delta, version=version)
async def adecr(self, key, delta=1, version=None):
return await self.aincr(key, -delta, version=version)
def __contains__(self, key):
"""
Return True if the key is in the cache and has not expired.
"""
# This is a separate method, rather than just a copy of has_key(),
# so that it always has the same functionality as has_key(), even
# if a subclass overrides it.
return self.has_key(key)
def set_many(self, data, timeout=DEFAULT_TIMEOUT, version=None):
"""
Set a bunch of values in the cache at once from a dict of key/value
pairs. For certain backends (memcached), this is much more efficient
than calling set() multiple times.
If timeout is given, use that timeout for the key; otherwise use the
default cache timeout.
On backends that support it, return a list of keys that failed
insertion, or an empty list if all keys were inserted successfully.
"""
for key, value in data.items():
self.set(key, value, timeout=timeout, version=version)
return []
async def aset_many(self, data, timeout=DEFAULT_TIMEOUT, version=None):
for key, value in data.items():
await self.aset(key, value, timeout=timeout, version=version)
return []
def delete_many(self, keys, version=None):
"""
Delete a bunch of values in the cache at once. For certain backends
(memcached), this is much more efficient than calling delete() multiple
times.
"""
for key in keys:
self.delete(key, version=version)
async def adelete_many(self, keys, version=None):
for key in keys:
await self.adelete(key, version=version)
def clear(self):
"""Remove *all* values from the cache at once."""
raise NotImplementedError('subclasses of BaseCache must provide a clear() method')
async def aclear(self):
return await sync_to_async(self.clear, thread_sensitive=True)()
def incr_version(self, key, delta=1, version=None):
"""
Add delta to the cache version for the supplied key. Return the new
version.
"""
if version is None:
version = self.version
value = self.get(key, self._missing_key, version=version)
if value is self._missing_key:
raise ValueError("Key '%s' not found" % key)
self.set(key, value, version=version + delta)
self.delete(key, version=version)
return version + delta
async def aincr_version(self, key, delta=1, version=None):
"""See incr_version()."""
if version is None:
version = self.version
value = await self.aget(key, self._missing_key, version=version)
if value is self._missing_key:
raise ValueError("Key '%s' not found" % key)
await self.aset(key, value, version=version + delta)
await self.adelete(key, version=version)
return version + delta
def decr_version(self, key, delta=1, version=None):
"""
Subtract delta from the cache version for the supplied key. Return the
new version.
"""
return self.incr_version(key, -delta, version)
async def adecr_version(self, key, delta=1, version=None):
return await self.aincr_version(key, -delta, version)
def close(self, **kwargs):
"""Close the cache connection"""
pass
async def aclose(self, **kwargs):
pass
def memcache_key_warnings(key):
if len(key) > MEMCACHE_MAX_KEY_LENGTH:
yield (
'Cache key will cause errors if used with memcached: %r '
'(longer than %s)' % (key, MEMCACHE_MAX_KEY_LENGTH)
)
for char in key:
if ord(char) < 33 or ord(char) == 127:
yield (
'Cache key contains characters that will cause errors if '
'used with memcached: %r' % key
)
break
|
7d06c588bef60e754a3fd514e160ec6586b160ac7b16530e261b4ff1a932da27 | "Dummy cache backend"
from django.core.cache.backends.base import DEFAULT_TIMEOUT, BaseCache
class DummyCache(BaseCache):
def __init__(self, host, *args, **kwargs):
super().__init__(*args, **kwargs)
def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
self.make_and_validate_key(key, version=version)
return True
def get(self, key, default=None, version=None):
self.make_and_validate_key(key, version=version)
return default
def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
self.make_and_validate_key(key, version=version)
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
self.make_and_validate_key(key, version=version)
return False
def delete(self, key, version=None):
self.make_and_validate_key(key, version=version)
return False
def has_key(self, key, version=None):
self.make_and_validate_key(key, version=version)
return False
def clear(self):
pass
|
72a74580fc58adf10a0ef291d88622155efe33084cd022073f12d307124c0d34 | "Thread-safe in-memory cache backend."
import pickle
import time
from collections import OrderedDict
from threading import Lock
from django.core.cache.backends.base import DEFAULT_TIMEOUT, BaseCache
# Global in-memory store of cache data. Keyed by name, to provide
# multiple named local memory caches.
_caches = {}
_expire_info = {}
_locks = {}
class LocMemCache(BaseCache):
pickle_protocol = pickle.HIGHEST_PROTOCOL
def __init__(self, name, params):
super().__init__(params)
self._cache = _caches.setdefault(name, OrderedDict())
self._expire_info = _expire_info.setdefault(name, {})
self._lock = _locks.setdefault(name, Lock())
def add(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
pickled = pickle.dumps(value, self.pickle_protocol)
with self._lock:
if self._has_expired(key):
self._set(key, pickled, timeout)
return True
return False
def get(self, key, default=None, version=None):
key = self.make_and_validate_key(key, version=version)
with self._lock:
if self._has_expired(key):
self._delete(key)
return default
pickled = self._cache[key]
self._cache.move_to_end(key, last=False)
return pickle.loads(pickled)
def _set(self, key, value, timeout=DEFAULT_TIMEOUT):
if len(self._cache) >= self._max_entries:
self._cull()
self._cache[key] = value
self._cache.move_to_end(key, last=False)
self._expire_info[key] = self.get_backend_timeout(timeout)
def set(self, key, value, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
pickled = pickle.dumps(value, self.pickle_protocol)
with self._lock:
self._set(key, pickled, timeout)
def touch(self, key, timeout=DEFAULT_TIMEOUT, version=None):
key = self.make_and_validate_key(key, version=version)
with self._lock:
if self._has_expired(key):
return False
self._expire_info[key] = self.get_backend_timeout(timeout)
return True
def incr(self, key, delta=1, version=None):
key = self.make_and_validate_key(key, version=version)
with self._lock:
if self._has_expired(key):
self._delete(key)
raise ValueError("Key '%s' not found" % key)
pickled = self._cache[key]
value = pickle.loads(pickled)
new_value = value + delta
pickled = pickle.dumps(new_value, self.pickle_protocol)
self._cache[key] = pickled
self._cache.move_to_end(key, last=False)
return new_value
def has_key(self, key, version=None):
key = self.make_and_validate_key(key, version=version)
with self._lock:
if self._has_expired(key):
self._delete(key)
return False
return True
def _has_expired(self, key):
exp = self._expire_info.get(key, -1)
return exp is not None and exp <= time.time()
def _cull(self):
if self._cull_frequency == 0:
self._cache.clear()
self._expire_info.clear()
else:
count = len(self._cache) // self._cull_frequency
for i in range(count):
key, _ = self._cache.popitem()
del self._expire_info[key]
def _delete(self, key):
try:
del self._cache[key]
del self._expire_info[key]
except KeyError:
return False
return True
def delete(self, key, version=None):
key = self.make_and_validate_key(key, version=version)
with self._lock:
return self._delete(key)
def clear(self):
with self._lock:
self._cache.clear()
self._expire_info.clear()
|
5e6c2524544033b0050d1d396a329c8510681d6b3763179956e1f33251a8ae15 | import warnings
from urllib.parse import urlencode
from urllib.request import urlopen
from django.apps import apps as django_apps
from django.conf import settings
from django.core import paginator
from django.core.exceptions import ImproperlyConfigured
from django.urls import NoReverseMatch, reverse
from django.utils import translation
from django.utils.deprecation import RemovedInDjango50Warning
PING_URL = "https://www.google.com/webmasters/tools/ping"
class SitemapNotFound(Exception):
pass
def ping_google(sitemap_url=None, ping_url=PING_URL, sitemap_uses_https=True):
"""
Alert Google that the sitemap for the current site has been updated.
If sitemap_url is provided, it should be an absolute path to the sitemap
for this site -- e.g., '/sitemap.xml'. If sitemap_url is not provided, this
function will attempt to deduce it by using urls.reverse().
"""
sitemap_full_url = _get_sitemap_full_url(sitemap_url, sitemap_uses_https)
params = urlencode({'sitemap': sitemap_full_url})
urlopen('%s?%s' % (ping_url, params))
def _get_sitemap_full_url(sitemap_url, sitemap_uses_https=True):
if not django_apps.is_installed('django.contrib.sites'):
raise ImproperlyConfigured("ping_google requires django.contrib.sites, which isn't installed.")
if sitemap_url is None:
try:
# First, try to get the "index" sitemap URL.
sitemap_url = reverse('django.contrib.sitemaps.views.index')
except NoReverseMatch:
try:
# Next, try for the "global" sitemap URL.
sitemap_url = reverse('django.contrib.sitemaps.views.sitemap')
except NoReverseMatch:
pass
if sitemap_url is None:
raise SitemapNotFound("You didn't provide a sitemap_url, and the sitemap URL couldn't be auto-detected.")
Site = django_apps.get_model('sites.Site')
current_site = Site.objects.get_current()
scheme = 'https' if sitemap_uses_https else 'http'
return '%s://%s%s' % (scheme, current_site.domain, sitemap_url)
class Sitemap:
# This limit is defined by Google. See the index documentation at
# https://www.sitemaps.org/protocol.html#index.
limit = 50000
# If protocol is None, the URLs in the sitemap will use the protocol
# with which the sitemap was requested.
protocol = None
# Enables generating URLs for all languages.
i18n = False
# Override list of languages to use.
languages = None
# Enables generating alternate/hreflang links.
alternates = False
# Add an alternate/hreflang link with value 'x-default'.
x_default = False
def _get(self, name, item, default=None):
try:
attr = getattr(self, name)
except AttributeError:
return default
if callable(attr):
if self.i18n:
# Split the (item, lang_code) tuples again for the location,
# priority, lastmod and changefreq method calls.
item, lang_code = item
return attr(item)
return attr
def _languages(self):
if self.languages is not None:
return self.languages
return [lang_code for lang_code, _ in settings.LANGUAGES]
def _items(self):
if self.i18n:
# Create (item, lang_code) tuples for all items and languages.
# This is necessary to paginate with all languages already considered.
items = [
(item, lang_code)
for lang_code in self._languages()
for item in self.items()
]
return items
return self.items()
def _location(self, item, force_lang_code=None):
if self.i18n:
obj, lang_code = item
# Activate language from item-tuple or forced one before calling location.
with translation.override(force_lang_code or lang_code):
return self._get('location', item)
return self._get('location', item)
@property
def paginator(self):
return paginator.Paginator(self._items(), self.limit)
def items(self):
return []
def location(self, item):
return item.get_absolute_url()
def get_protocol(self, protocol=None):
# Determine protocol
if self.protocol is None and protocol is None:
warnings.warn(
"The default sitemap protocol will be changed from 'http' to "
"'https' in Django 5.0. Set Sitemap.protocol to silence this "
"warning.",
category=RemovedInDjango50Warning,
stacklevel=2,
)
# RemovedInDjango50Warning: when the deprecation ends, replace 'http'
# with 'https'.
return self.protocol or protocol or 'http'
def get_domain(self, site=None):
# Determine domain
if site is None:
if django_apps.is_installed('django.contrib.sites'):
Site = django_apps.get_model('sites.Site')
try:
site = Site.objects.get_current()
except Site.DoesNotExist:
pass
if site is None:
raise ImproperlyConfigured(
"To use sitemaps, either enable the sites framework or pass "
"a Site/RequestSite object in your view."
)
return site.domain
def get_urls(self, page=1, site=None, protocol=None):
protocol = self.get_protocol(protocol)
domain = self.get_domain(site)
return self._urls(page, protocol, domain)
def get_latest_lastmod(self):
if not hasattr(self, 'lastmod'):
return None
if callable(self.lastmod):
try:
return max([self.lastmod(item) for item in self.items()])
except TypeError:
return None
else:
return self.lastmod
def _urls(self, page, protocol, domain):
urls = []
latest_lastmod = None
all_items_lastmod = True # track if all items have a lastmod
paginator_page = self.paginator.page(page)
for item in paginator_page.object_list:
loc = f'{protocol}://{domain}{self._location(item)}'
priority = self._get('priority', item)
lastmod = self._get('lastmod', item)
if all_items_lastmod:
all_items_lastmod = lastmod is not None
if (all_items_lastmod and
(latest_lastmod is None or lastmod > latest_lastmod)):
latest_lastmod = lastmod
url_info = {
'item': item,
'location': loc,
'lastmod': lastmod,
'changefreq': self._get('changefreq', item),
'priority': str(priority if priority is not None else ''),
'alternates': [],
}
if self.i18n and self.alternates:
for lang_code in self._languages():
loc = f'{protocol}://{domain}{self._location(item, lang_code)}'
url_info['alternates'].append({
'location': loc,
'lang_code': lang_code,
})
if self.x_default:
lang_code = settings.LANGUAGE_CODE
loc = f'{protocol}://{domain}{self._location(item, lang_code)}'
loc = loc.replace(f'/{lang_code}/', '/', 1)
url_info['alternates'].append({
'location': loc,
'lang_code': 'x-default',
})
urls.append(url_info)
if all_items_lastmod and latest_lastmod:
self.latest_lastmod = latest_lastmod
return urls
class GenericSitemap(Sitemap):
priority = None
changefreq = None
def __init__(self, info_dict, priority=None, changefreq=None, protocol=None):
self.queryset = info_dict['queryset']
self.date_field = info_dict.get('date_field')
self.priority = self.priority or priority
self.changefreq = self.changefreq or changefreq
self.protocol = self.protocol or protocol
def items(self):
# Make sure to return a clone; we don't want premature evaluation.
return self.queryset.filter()
def lastmod(self, item):
if self.date_field is not None:
return getattr(item, self.date_field)
return None
def get_latest_lastmod(self):
if self.date_field is not None:
return self.queryset.order_by('-' + self.date_field).values_list(self.date_field, flat=True).first()
return None
|
541b9ffc550e0a3d50c61ce3381625595ae2a3a6ac5a42a030f1b37abdbf329c | import datetime
import warnings
from dataclasses import dataclass
from functools import wraps
from django.contrib.sites.shortcuts import get_current_site
from django.core.paginator import EmptyPage, PageNotAnInteger
from django.http import Http404
from django.template.response import TemplateResponse
from django.urls import reverse
from django.utils import timezone
from django.utils.deprecation import RemovedInDjango50Warning
from django.utils.http import http_date
@dataclass
class SitemapIndexItem:
location: str
last_mod: bool = None
# RemovedInDjango50Warning
def __str__(self):
msg = 'Calling `__str__` on SitemapIndexItem is deprecated, use the `location` attribute instead.'
warnings.warn(msg, RemovedInDjango50Warning, stacklevel=2)
return self.location
def x_robots_tag(func):
@wraps(func)
def inner(request, *args, **kwargs):
response = func(request, *args, **kwargs)
response.headers['X-Robots-Tag'] = 'noindex, noodp, noarchive'
return response
return inner
def _get_latest_lastmod(current_lastmod, new_lastmod):
"""
Returns the latest `lastmod` where `lastmod` can be either a date or a
datetime.
"""
if not isinstance(new_lastmod, datetime.datetime):
new_lastmod = datetime.datetime.combine(new_lastmod, datetime.time.min)
if timezone.is_naive(new_lastmod):
new_lastmod = timezone.make_aware(new_lastmod, timezone.utc)
return new_lastmod if current_lastmod is None else max(current_lastmod, new_lastmod)
@x_robots_tag
def index(request, sitemaps,
template_name='sitemap_index.xml', content_type='application/xml',
sitemap_url_name='django.contrib.sitemaps.views.sitemap'):
req_protocol = request.scheme
req_site = get_current_site(request)
sites = [] # all sections' sitemap URLs
all_indexes_lastmod = True
latest_lastmod = None
for section, site in sitemaps.items():
# For each section label, add links of all pages of its sitemap
# (usually generated by the `sitemap` view).
if callable(site):
site = site()
protocol = req_protocol if site.protocol is None else site.protocol
sitemap_url = reverse(sitemap_url_name, kwargs={'section': section})
absolute_url = '%s://%s%s' % (protocol, req_site.domain, sitemap_url)
site_lastmod = site.get_latest_lastmod()
if all_indexes_lastmod:
if site_lastmod is not None:
latest_lastmod = _get_latest_lastmod(latest_lastmod, site_lastmod)
else:
all_indexes_lastmod = False
sites.append(SitemapIndexItem(absolute_url, site_lastmod))
# Add links to all pages of the sitemap.
for page in range(2, site.paginator.num_pages + 1):
sites.append(SitemapIndexItem('%s?p=%s' % (absolute_url, page), site_lastmod))
# If lastmod is defined for all sites, set header so as
# ConditionalGetMiddleware is able to send 304 NOT MODIFIED
if all_indexes_lastmod and latest_lastmod:
headers = {'Last-Modified': http_date(latest_lastmod.timestamp())}
else:
headers = None
return TemplateResponse(
request,
template_name,
{'sitemaps': sites},
content_type=content_type,
headers=headers,
)
@x_robots_tag
def sitemap(request, sitemaps, section=None,
template_name='sitemap.xml', content_type='application/xml'):
req_protocol = request.scheme
req_site = get_current_site(request)
if section is not None:
if section not in sitemaps:
raise Http404("No sitemap available for section: %r" % section)
maps = [sitemaps[section]]
else:
maps = sitemaps.values()
page = request.GET.get("p", 1)
lastmod = None
all_sites_lastmod = True
urls = []
for site in maps:
try:
if callable(site):
site = site()
urls.extend(site.get_urls(page=page, site=req_site,
protocol=req_protocol))
if all_sites_lastmod:
site_lastmod = getattr(site, 'latest_lastmod', None)
if site_lastmod is not None:
lastmod = _get_latest_lastmod(lastmod, site_lastmod)
else:
all_sites_lastmod = False
except EmptyPage:
raise Http404("Page %s empty" % page)
except PageNotAnInteger:
raise Http404("No page '%s'" % page)
# If lastmod is defined for all sites, set header so as
# ConditionalGetMiddleware is able to send 304 NOT MODIFIED
if all_sites_lastmod:
headers = {'Last-Modified': http_date(lastmod.timestamp())} if lastmod else None
else:
headers = None
return TemplateResponse(
request,
template_name,
{'urlset': urls},
content_type=content_type,
headers=headers,
)
|
4a26952588edc6fc0baec40849e39e7ff8df267dda3945d9922a98625867a9ea | from django.apps import AppConfig
from django.contrib.messages.storage import base
from django.contrib.messages.utils import get_level_tags
from django.core.signals import setting_changed
from django.utils.translation import gettext_lazy as _
def update_level_tags(setting, **kwargs):
if setting == 'MESSAGE_TAGS':
base.LEVEL_TAGS = get_level_tags()
class MessagesConfig(AppConfig):
name = 'django.contrib.messages'
verbose_name = _("Messages")
def ready(self):
setting_changed.connect(update_level_tags)
|
b17c18874abcdd6db1913e0be5544cfbd7eac6a0bae550e40a7d0fcefb86e295 | "Misc. utility functions/classes for admin documentation generator."
import re
from email.errors import HeaderParseError
from email.parser import HeaderParser
from inspect import cleandoc
from django.urls import reverse
from django.utils.regex_helper import _lazy_re_compile
from django.utils.safestring import mark_safe
try:
import docutils.core
import docutils.nodes
import docutils.parsers.rst.roles
except ImportError:
docutils_is_available = False
else:
docutils_is_available = True
def get_view_name(view_func):
if hasattr(view_func, 'view_class'):
klass = view_func.view_class
return f'{klass.__module__}.{klass.__qualname__}'
mod_name = view_func.__module__
view_name = getattr(view_func, '__qualname__', view_func.__class__.__name__)
return mod_name + '.' + view_name
def parse_docstring(docstring):
"""
Parse out the parts of a docstring. Return (title, body, metadata).
"""
if not docstring:
return '', '', {}
docstring = cleandoc(docstring)
parts = re.split(r'\n{2,}', docstring)
title = parts[0]
if len(parts) == 1:
body = ''
metadata = {}
else:
parser = HeaderParser()
try:
metadata = parser.parsestr(parts[-1])
except HeaderParseError:
metadata = {}
body = "\n\n".join(parts[1:])
else:
metadata = dict(metadata.items())
if metadata:
body = "\n\n".join(parts[1:-1])
else:
body = "\n\n".join(parts[1:])
return title, body, metadata
def parse_rst(text, default_reference_context, thing_being_parsed=None):
"""
Convert the string from reST to an XHTML fragment.
"""
overrides = {
'doctitle_xform': True,
'initial_header_level': 3,
"default_reference_context": default_reference_context,
"link_base": reverse('django-admindocs-docroot').rstrip('/'),
'raw_enabled': False,
'file_insertion_enabled': False,
}
thing_being_parsed = thing_being_parsed and '<%s>' % thing_being_parsed
# Wrap ``text`` in some reST that sets the default role to ``cmsreference``,
# then restores it.
source = """
.. default-role:: cmsreference
%s
.. default-role::
"""
parts = docutils.core.publish_parts(
source % text,
source_path=thing_being_parsed, destination_path=None,
writer_name='html', settings_overrides=overrides,
)
return mark_safe(parts['fragment'])
#
# reST roles
#
ROLES = {
'model': '%s/models/%s/',
'view': '%s/views/%s/',
'template': '%s/templates/%s/',
'filter': '%s/filters/#%s',
'tag': '%s/tags/#%s',
}
def create_reference_role(rolename, urlbase):
def _role(name, rawtext, text, lineno, inliner, options=None, content=None):
if options is None:
options = {}
node = docutils.nodes.reference(
rawtext,
text,
refuri=(urlbase % (
inliner.document.settings.link_base,
text.lower(),
)),
**options
)
return [node], []
docutils.parsers.rst.roles.register_canonical_role(rolename, _role)
def default_reference_role(name, rawtext, text, lineno, inliner, options=None, content=None):
if options is None:
options = {}
context = inliner.document.settings.default_reference_context
node = docutils.nodes.reference(
rawtext,
text,
refuri=(ROLES[context] % (
inliner.document.settings.link_base,
text.lower(),
)),
**options
)
return [node], []
if docutils_is_available:
docutils.parsers.rst.roles.register_canonical_role('cmsreference', default_reference_role)
for name, urlbase in ROLES.items():
create_reference_role(name, urlbase)
# Match the beginning of a named, unnamed, or non-capturing groups.
named_group_matcher = _lazy_re_compile(r'\(\?P(<\w+>)')
unnamed_group_matcher = _lazy_re_compile(r'\(')
non_capturing_group_matcher = _lazy_re_compile(r'\(\?\:')
def replace_metacharacters(pattern):
"""Remove unescaped metacharacters from the pattern."""
return re.sub(
r'((?:^|(?<!\\))(?:\\\\)*)(\\?)([?*+^$]|\\[bBAZ])',
lambda m: m[1] + m[3] if m[2] else m[1],
pattern,
)
def _get_group_start_end(start, end, pattern):
# Handle nested parentheses, e.g. '^(?P<a>(x|y))/b' or '^b/((x|y)\w+)$'.
unmatched_open_brackets, prev_char = 1, None
for idx, val in enumerate(pattern[end:]):
# Check for unescaped `(` and `)`. They mark the start and end of a
# nested group.
if val == '(' and prev_char != '\\':
unmatched_open_brackets += 1
elif val == ')' and prev_char != '\\':
unmatched_open_brackets -= 1
prev_char = val
# If brackets are balanced, the end of the string for the current named
# capture group pattern has been reached.
if unmatched_open_brackets == 0:
return start, end + idx + 1
def _find_groups(pattern, group_matcher):
prev_end = None
for match in group_matcher.finditer(pattern):
if indices := _get_group_start_end(match.start(0), match.end(0), pattern):
start, end = indices
if prev_end and start > prev_end or not prev_end:
yield start, end, match
prev_end = end
def replace_named_groups(pattern):
r"""
Find named groups in `pattern` and replace them with the group name. E.g.,
1. ^(?P<a>\w+)/b/(\w+)$ ==> ^<a>/b/(\w+)$
2. ^(?P<a>\w+)/b/(?P<c>\w+)/$ ==> ^<a>/b/<c>/$
3. ^(?P<a>\w+)/b/(\w+) ==> ^<a>/b/(\w+)
4. ^(?P<a>\w+)/b/(?P<c>\w+) ==> ^<a>/b/<c>
"""
group_pattern_and_name = [
(pattern[start:end], match[1])
for start, end, match in _find_groups(pattern, named_group_matcher)
]
for group_pattern, group_name in group_pattern_and_name:
pattern = pattern.replace(group_pattern, group_name)
return pattern
def replace_unnamed_groups(pattern):
r"""
Find unnamed groups in `pattern` and replace them with '<var>'. E.g.,
1. ^(?P<a>\w+)/b/(\w+)$ ==> ^(?P<a>\w+)/b/<var>$
2. ^(?P<a>\w+)/b/((x|y)\w+)$ ==> ^(?P<a>\w+)/b/<var>$
3. ^(?P<a>\w+)/b/(\w+) ==> ^(?P<a>\w+)/b/<var>
4. ^(?P<a>\w+)/b/((x|y)\w+) ==> ^(?P<a>\w+)/b/<var>
"""
final_pattern, prev_end = '', None
for start, end, _ in _find_groups(pattern, unnamed_group_matcher):
if prev_end:
final_pattern += pattern[prev_end:start]
final_pattern += pattern[:start] + '<var>'
prev_end = end
return final_pattern + pattern[prev_end:]
def remove_non_capturing_groups(pattern):
r"""
Find non-capturing groups in the given `pattern` and remove them, e.g.
1. (?P<a>\w+)/b/(?:\w+)c(?:\w+) => (?P<a>\\w+)/b/c
2. ^(?:\w+(?:\w+))a => ^a
3. ^a(?:\w+)/b(?:\w+) => ^a/b
"""
group_start_end_indices = _find_groups(pattern, non_capturing_group_matcher)
final_pattern, prev_end = '', None
for start, end, _ in group_start_end_indices:
final_pattern += pattern[prev_end:start]
prev_end = end
return final_pattern + pattern[prev_end:]
|
adba73fedc9ffc89b1444eb0bf1bd4841b45d7ae31efaa15db41c4084421123c | import inspect
from importlib import import_module
from inspect import cleandoc
from pathlib import Path
from django.apps import apps
from django.contrib import admin
from django.contrib.admin.views.decorators import staff_member_required
from django.contrib.admindocs import utils
from django.contrib.admindocs.utils import (
remove_non_capturing_groups, replace_metacharacters, replace_named_groups,
replace_unnamed_groups,
)
from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
from django.db import models
from django.http import Http404
from django.template.engine import Engine
from django.urls import get_mod_func, get_resolver, get_urlconf
from django.utils._os import safe_join
from django.utils.decorators import method_decorator
from django.utils.functional import cached_property
from django.utils.inspect import (
func_accepts_kwargs, func_accepts_var_args, get_func_full_args,
method_has_no_args,
)
from django.utils.translation import gettext as _
from django.views.generic import TemplateView
from .utils import get_view_name
# Exclude methods starting with these strings from documentation
MODEL_METHODS_EXCLUDE = ('_', 'add_', 'delete', 'save', 'set_')
class BaseAdminDocsView(TemplateView):
"""
Base view for admindocs views.
"""
@method_decorator(staff_member_required)
def dispatch(self, request, *args, **kwargs):
if not utils.docutils_is_available:
# Display an error message for people without docutils
self.template_name = 'admin_doc/missing_docutils.html'
return self.render_to_response(admin.site.each_context(request))
return super().dispatch(request, *args, **kwargs)
def get_context_data(self, **kwargs):
return super().get_context_data(**{
**kwargs,
**admin.site.each_context(self.request),
})
class BookmarkletsView(BaseAdminDocsView):
template_name = 'admin_doc/bookmarklets.html'
class TemplateTagIndexView(BaseAdminDocsView):
template_name = 'admin_doc/template_tag_index.html'
def get_context_data(self, **kwargs):
tags = []
try:
engine = Engine.get_default()
except ImproperlyConfigured:
# Non-trivial TEMPLATES settings aren't supported (#24125).
pass
else:
app_libs = sorted(engine.template_libraries.items())
builtin_libs = [('', lib) for lib in engine.template_builtins]
for module_name, library in builtin_libs + app_libs:
for tag_name, tag_func in library.tags.items():
title, body, metadata = utils.parse_docstring(tag_func.__doc__)
title = title and utils.parse_rst(title, 'tag', _('tag:') + tag_name)
body = body and utils.parse_rst(body, 'tag', _('tag:') + tag_name)
for key in metadata:
metadata[key] = utils.parse_rst(metadata[key], 'tag', _('tag:') + tag_name)
tag_library = module_name.split('.')[-1]
tags.append({
'name': tag_name,
'title': title,
'body': body,
'meta': metadata,
'library': tag_library,
})
return super().get_context_data(**{**kwargs, 'tags': tags})
class TemplateFilterIndexView(BaseAdminDocsView):
template_name = 'admin_doc/template_filter_index.html'
def get_context_data(self, **kwargs):
filters = []
try:
engine = Engine.get_default()
except ImproperlyConfigured:
# Non-trivial TEMPLATES settings aren't supported (#24125).
pass
else:
app_libs = sorted(engine.template_libraries.items())
builtin_libs = [('', lib) for lib in engine.template_builtins]
for module_name, library in builtin_libs + app_libs:
for filter_name, filter_func in library.filters.items():
title, body, metadata = utils.parse_docstring(filter_func.__doc__)
title = title and utils.parse_rst(title, 'filter', _('filter:') + filter_name)
body = body and utils.parse_rst(body, 'filter', _('filter:') + filter_name)
for key in metadata:
metadata[key] = utils.parse_rst(metadata[key], 'filter', _('filter:') + filter_name)
tag_library = module_name.split('.')[-1]
filters.append({
'name': filter_name,
'title': title,
'body': body,
'meta': metadata,
'library': tag_library,
})
return super().get_context_data(**{**kwargs, 'filters': filters})
class ViewIndexView(BaseAdminDocsView):
template_name = 'admin_doc/view_index.html'
def get_context_data(self, **kwargs):
views = []
url_resolver = get_resolver(get_urlconf())
try:
view_functions = extract_views_from_urlpatterns(url_resolver.url_patterns)
except ImproperlyConfigured:
view_functions = []
for (func, regex, namespace, name) in view_functions:
views.append({
'full_name': get_view_name(func),
'url': simplify_regex(regex),
'url_name': ':'.join((namespace or []) + (name and [name] or [])),
'namespace': ':'.join(namespace or []),
'name': name,
})
return super().get_context_data(**{**kwargs, 'views': views})
class ViewDetailView(BaseAdminDocsView):
template_name = 'admin_doc/view_detail.html'
@staticmethod
def _get_view_func(view):
urlconf = get_urlconf()
if get_resolver(urlconf)._is_callback(view):
mod, func = get_mod_func(view)
try:
# Separate the module and function, e.g.
# 'mymodule.views.myview' -> 'mymodule.views', 'myview').
return getattr(import_module(mod), func)
except ImportError:
# Import may fail because view contains a class name, e.g.
# 'mymodule.views.ViewContainer.my_view', so mod takes the form
# 'mymodule.views.ViewContainer'. Parse it again to separate
# the module and class.
mod, klass = get_mod_func(mod)
return getattr(getattr(import_module(mod), klass), func)
def get_context_data(self, **kwargs):
view = self.kwargs['view']
view_func = self._get_view_func(view)
if view_func is None:
raise Http404
title, body, metadata = utils.parse_docstring(view_func.__doc__)
title = title and utils.parse_rst(title, 'view', _('view:') + view)
body = body and utils.parse_rst(body, 'view', _('view:') + view)
for key in metadata:
metadata[key] = utils.parse_rst(metadata[key], 'model', _('view:') + view)
return super().get_context_data(**{
**kwargs,
'name': view,
'summary': title,
'body': body,
'meta': metadata,
})
class ModelIndexView(BaseAdminDocsView):
template_name = 'admin_doc/model_index.html'
def get_context_data(self, **kwargs):
m_list = [m._meta for m in apps.get_models()]
return super().get_context_data(**{**kwargs, 'models': m_list})
class ModelDetailView(BaseAdminDocsView):
template_name = 'admin_doc/model_detail.html'
def get_context_data(self, **kwargs):
model_name = self.kwargs['model_name']
# Get the model class.
try:
app_config = apps.get_app_config(self.kwargs['app_label'])
except LookupError:
raise Http404(_("App %(app_label)r not found") % self.kwargs)
try:
model = app_config.get_model(model_name)
except LookupError:
raise Http404(_("Model %(model_name)r not found in app %(app_label)r") % self.kwargs)
opts = model._meta
title, body, metadata = utils.parse_docstring(model.__doc__)
title = title and utils.parse_rst(title, 'model', _('model:') + model_name)
body = body and utils.parse_rst(body, 'model', _('model:') + model_name)
# Gather fields/field descriptions.
fields = []
for field in opts.fields:
# ForeignKey is a special case since the field will actually be a
# descriptor that returns the other object
if isinstance(field, models.ForeignKey):
data_type = field.remote_field.model.__name__
app_label = field.remote_field.model._meta.app_label
verbose = utils.parse_rst(
(_("the related `%(app_label)s.%(data_type)s` object") % {
'app_label': app_label, 'data_type': data_type,
}),
'model',
_('model:') + data_type,
)
else:
data_type = get_readable_field_data_type(field)
verbose = field.verbose_name
fields.append({
'name': field.name,
'data_type': data_type,
'verbose': verbose or '',
'help_text': field.help_text,
})
# Gather many-to-many fields.
for field in opts.many_to_many:
data_type = field.remote_field.model.__name__
app_label = field.remote_field.model._meta.app_label
verbose = _("related `%(app_label)s.%(object_name)s` objects") % {
'app_label': app_label,
'object_name': data_type,
}
fields.append({
'name': "%s.all" % field.name,
"data_type": 'List',
'verbose': utils.parse_rst(_("all %s") % verbose, 'model', _('model:') + opts.model_name),
})
fields.append({
'name': "%s.count" % field.name,
'data_type': 'Integer',
'verbose': utils.parse_rst(_("number of %s") % verbose, 'model', _('model:') + opts.model_name),
})
methods = []
# Gather model methods.
for func_name, func in model.__dict__.items():
if inspect.isfunction(func) or isinstance(func, (cached_property, property)):
try:
for exclude in MODEL_METHODS_EXCLUDE:
if func_name.startswith(exclude):
raise StopIteration
except StopIteration:
continue
verbose = func.__doc__
verbose = verbose and (
utils.parse_rst(cleandoc(verbose), 'model', _('model:') + opts.model_name)
)
# Show properties, cached_properties, and methods without
# arguments as fields. Otherwise, show as a 'method with
# arguments'.
if isinstance(func, (cached_property, property)):
fields.append({
'name': func_name,
'data_type': get_return_data_type(func_name),
'verbose': verbose or ''
})
elif method_has_no_args(func) and not func_accepts_kwargs(func) and not func_accepts_var_args(func):
fields.append({
'name': func_name,
'data_type': get_return_data_type(func_name),
'verbose': verbose or '',
})
else:
arguments = get_func_full_args(func)
# Join arguments with ', ' and in case of default value,
# join it with '='. Use repr() so that strings will be
# correctly displayed.
print_arguments = ', '.join([
'='.join([arg_el[0], *map(repr, arg_el[1:])])
for arg_el in arguments
])
methods.append({
'name': func_name,
'arguments': print_arguments,
'verbose': verbose or '',
})
# Gather related objects
for rel in opts.related_objects:
verbose = _("related `%(app_label)s.%(object_name)s` objects") % {
'app_label': rel.related_model._meta.app_label,
'object_name': rel.related_model._meta.object_name,
}
accessor = rel.get_accessor_name()
fields.append({
'name': "%s.all" % accessor,
'data_type': 'List',
'verbose': utils.parse_rst(_("all %s") % verbose, 'model', _('model:') + opts.model_name),
})
fields.append({
'name': "%s.count" % accessor,
'data_type': 'Integer',
'verbose': utils.parse_rst(_("number of %s") % verbose, 'model', _('model:') + opts.model_name),
})
return super().get_context_data(**{
**kwargs,
'name': opts.label,
'summary': title,
'description': body,
'fields': fields,
'methods': methods,
})
class TemplateDetailView(BaseAdminDocsView):
template_name = 'admin_doc/template_detail.html'
def get_context_data(self, **kwargs):
template = self.kwargs['template']
templates = []
try:
default_engine = Engine.get_default()
except ImproperlyConfigured:
# Non-trivial TEMPLATES settings aren't supported (#24125).
pass
else:
# This doesn't account for template loaders (#24128).
for index, directory in enumerate(default_engine.dirs):
template_file = Path(safe_join(directory, template))
if template_file.exists():
template_contents = template_file.read_text()
else:
template_contents = ''
templates.append({
'file': template_file,
'exists': template_file.exists(),
'contents': template_contents,
'order': index,
})
return super().get_context_data(**{
**kwargs,
'name': template,
'templates': templates,
})
####################
# Helper functions #
####################
def get_return_data_type(func_name):
"""Return a somewhat-helpful data type given a function name"""
if func_name.startswith('get_'):
if func_name.endswith('_list'):
return 'List'
elif func_name.endswith('_count'):
return 'Integer'
return ''
def get_readable_field_data_type(field):
"""
Return the description for a given field type, if it exists. Fields'
descriptions can contain format strings, which will be interpolated with
the values of field.__dict__ before being output.
"""
return field.description % field.__dict__
def extract_views_from_urlpatterns(urlpatterns, base='', namespace=None):
"""
Return a list of views from a list of urlpatterns.
Each object in the returned list is a two-tuple: (view_func, regex)
"""
views = []
for p in urlpatterns:
if hasattr(p, 'url_patterns'):
try:
patterns = p.url_patterns
except ImportError:
continue
views.extend(extract_views_from_urlpatterns(
patterns,
base + str(p.pattern),
(namespace or []) + (p.namespace and [p.namespace] or [])
))
elif hasattr(p, 'callback'):
try:
views.append((p.callback, base + str(p.pattern), namespace, p.name))
except ViewDoesNotExist:
continue
else:
raise TypeError(_("%s does not appear to be a urlpattern object") % p)
return views
def simplify_regex(pattern):
r"""
Clean up urlpattern regexes into something more readable by humans. For
example, turn "^(?P<sport_slug>\w+)/athletes/(?P<athlete_slug>\w+)/$"
into "/<sport_slug>/athletes/<athlete_slug>/".
"""
pattern = remove_non_capturing_groups(pattern)
pattern = replace_named_groups(pattern)
pattern = replace_unnamed_groups(pattern)
pattern = replace_metacharacters(pattern)
if not pattern.startswith('/'):
pattern = '/' + pattern
return pattern
|
45a07f9e934d6ac2b0c49757533c8cb5201eb929549a6ff93ac8eda5134ab413 | from django.db import NotSupportedError
from django.db.models import Func, Index
from django.utils.functional import cached_property
__all__ = [
'BloomIndex', 'BrinIndex', 'BTreeIndex', 'GinIndex', 'GistIndex',
'HashIndex', 'SpGistIndex',
]
class PostgresIndex(Index):
@cached_property
def max_name_length(self):
# Allow an index name longer than 30 characters when the suffix is
# longer than the usual 3 character limit. The 30 character limit for
# cross-database compatibility isn't applicable to PostgreSQL-specific
# indexes.
return Index.max_name_length - len(Index.suffix) + len(self.suffix)
def create_sql(self, model, schema_editor, using='', **kwargs):
self.check_supported(schema_editor)
statement = super().create_sql(model, schema_editor, using=' USING %s' % self.suffix, **kwargs)
with_params = self.get_with_params()
if with_params:
statement.parts['extra'] = 'WITH (%s) %s' % (
', '.join(with_params),
statement.parts['extra'],
)
return statement
def check_supported(self, schema_editor):
pass
def get_with_params(self):
return []
class BloomIndex(PostgresIndex):
suffix = 'bloom'
def __init__(self, *expressions, length=None, columns=(), **kwargs):
super().__init__(*expressions, **kwargs)
if len(self.fields) > 32:
raise ValueError('Bloom indexes support a maximum of 32 fields.')
if not isinstance(columns, (list, tuple)):
raise ValueError('BloomIndex.columns must be a list or tuple.')
if len(columns) > len(self.fields):
raise ValueError(
'BloomIndex.columns cannot have more values than fields.'
)
if not all(0 < col <= 4095 for col in columns):
raise ValueError(
'BloomIndex.columns must contain integers from 1 to 4095.',
)
if length is not None and not 0 < length <= 4096:
raise ValueError(
'BloomIndex.length must be None or an integer from 1 to 4096.',
)
self.length = length
self.columns = columns
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.length is not None:
kwargs['length'] = self.length
if self.columns:
kwargs['columns'] = self.columns
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.length is not None:
with_params.append('length = %d' % self.length)
if self.columns:
with_params.extend(
'col%d = %d' % (i, v)
for i, v in enumerate(self.columns, start=1)
)
return with_params
class BrinIndex(PostgresIndex):
suffix = 'brin'
def __init__(self, *expressions, autosummarize=None, pages_per_range=None, **kwargs):
if pages_per_range is not None and pages_per_range <= 0:
raise ValueError('pages_per_range must be None or a positive integer')
self.autosummarize = autosummarize
self.pages_per_range = pages_per_range
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.autosummarize is not None:
kwargs['autosummarize'] = self.autosummarize
if self.pages_per_range is not None:
kwargs['pages_per_range'] = self.pages_per_range
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.autosummarize is not None:
with_params.append('autosummarize = %s' % ('on' if self.autosummarize else 'off'))
if self.pages_per_range is not None:
with_params.append('pages_per_range = %d' % self.pages_per_range)
return with_params
class BTreeIndex(PostgresIndex):
suffix = 'btree'
def __init__(self, *expressions, fillfactor=None, **kwargs):
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
class GinIndex(PostgresIndex):
suffix = 'gin'
def __init__(self, *expressions, fastupdate=None, gin_pending_list_limit=None, **kwargs):
self.fastupdate = fastupdate
self.gin_pending_list_limit = gin_pending_list_limit
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fastupdate is not None:
kwargs['fastupdate'] = self.fastupdate
if self.gin_pending_list_limit is not None:
kwargs['gin_pending_list_limit'] = self.gin_pending_list_limit
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.gin_pending_list_limit is not None:
with_params.append('gin_pending_list_limit = %d' % self.gin_pending_list_limit)
if self.fastupdate is not None:
with_params.append('fastupdate = %s' % ('on' if self.fastupdate else 'off'))
return with_params
class GistIndex(PostgresIndex):
suffix = 'gist'
def __init__(self, *expressions, buffering=None, fillfactor=None, **kwargs):
self.buffering = buffering
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.buffering is not None:
kwargs['buffering'] = self.buffering
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.buffering is not None:
with_params.append('buffering = %s' % ('on' if self.buffering else 'off'))
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
def check_supported(self, schema_editor):
if self.include and not schema_editor.connection.features.supports_covering_gist_indexes:
raise NotSupportedError('Covering GiST indexes require PostgreSQL 12+.')
class HashIndex(PostgresIndex):
suffix = 'hash'
def __init__(self, *expressions, fillfactor=None, **kwargs):
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
class SpGistIndex(PostgresIndex):
suffix = 'spgist'
def __init__(self, *expressions, fillfactor=None, **kwargs):
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
def check_supported(self, schema_editor):
if (
self.include and
not schema_editor.connection.features.supports_covering_spgist_indexes
):
raise NotSupportedError('Covering SP-GiST indexes require PostgreSQL 14+.')
class OpClass(Func):
template = '%(expressions)s %(name)s'
def __init__(self, expression, name):
super().__init__(expression, name=name)
|
ff63ec975c0ca6391bdc01b99e5bb0e6c712e7a8793a1dd8ab092f7c8bb2db16 | import psycopg2
from django.db.models import (
CharField, Expression, Field, FloatField, Func, Lookup, TextField, Value,
)
from django.db.models.expressions import CombinedExpression
from django.db.models.functions import Cast, Coalesce
class SearchVectorExact(Lookup):
lookup_name = 'exact'
def process_rhs(self, qn, connection):
if not isinstance(self.rhs, (SearchQuery, CombinedSearchQuery)):
config = getattr(self.lhs, 'config', None)
self.rhs = SearchQuery(self.rhs, config=config)
rhs, rhs_params = super().process_rhs(qn, connection)
return rhs, rhs_params
def as_sql(self, qn, connection):
lhs, lhs_params = self.process_lhs(qn, connection)
rhs, rhs_params = self.process_rhs(qn, connection)
params = lhs_params + rhs_params
return '%s @@ %s' % (lhs, rhs), params
class SearchVectorField(Field):
def db_type(self, connection):
return 'tsvector'
class SearchQueryField(Field):
def db_type(self, connection):
return 'tsquery'
class SearchConfig(Expression):
def __init__(self, config):
super().__init__()
if not hasattr(config, 'resolve_expression'):
config = Value(config)
self.config = config
@classmethod
def from_parameter(cls, config):
if config is None or isinstance(config, cls):
return config
return cls(config)
def get_source_expressions(self):
return [self.config]
def set_source_expressions(self, exprs):
self.config, = exprs
def as_sql(self, compiler, connection):
sql, params = compiler.compile(self.config)
return '%s::regconfig' % sql, params
class SearchVectorCombinable:
ADD = '||'
def _combine(self, other, connector, reversed):
if not isinstance(other, SearchVectorCombinable):
raise TypeError(
'SearchVector can only be combined with other SearchVector '
'instances, got %s.' % type(other).__name__
)
if reversed:
return CombinedSearchVector(other, connector, self, self.config)
return CombinedSearchVector(self, connector, other, self.config)
class SearchVector(SearchVectorCombinable, Func):
function = 'to_tsvector'
arg_joiner = " || ' ' || "
output_field = SearchVectorField()
def __init__(self, *expressions, config=None, weight=None):
super().__init__(*expressions)
self.config = SearchConfig.from_parameter(config)
if weight is not None and not hasattr(weight, 'resolve_expression'):
weight = Value(weight)
self.weight = weight
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
resolved = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
if self.config:
resolved.config = self.config.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return resolved
def as_sql(self, compiler, connection, function=None, template=None):
clone = self.copy()
clone.set_source_expressions([
Coalesce(
expression
if isinstance(expression.output_field, (CharField, TextField))
else Cast(expression, TextField()),
Value('')
) for expression in clone.get_source_expressions()
])
config_sql = None
config_params = []
if template is None:
if clone.config:
config_sql, config_params = compiler.compile(clone.config)
template = '%(function)s(%(config)s, %(expressions)s)'
else:
template = clone.template
sql, params = super(SearchVector, clone).as_sql(
compiler, connection, function=function, template=template,
config=config_sql,
)
extra_params = []
if clone.weight:
weight_sql, extra_params = compiler.compile(clone.weight)
sql = 'setweight({}, {})'.format(sql, weight_sql)
return sql, config_params + params + extra_params
class CombinedSearchVector(SearchVectorCombinable, CombinedExpression):
def __init__(self, lhs, connector, rhs, config, output_field=None):
self.config = config
super().__init__(lhs, connector, rhs, output_field)
class SearchQueryCombinable:
BITAND = '&&'
BITOR = '||'
def _combine(self, other, connector, reversed):
if not isinstance(other, SearchQueryCombinable):
raise TypeError(
'SearchQuery can only be combined with other SearchQuery '
'instances, got %s.' % type(other).__name__
)
if reversed:
return CombinedSearchQuery(other, connector, self, self.config)
return CombinedSearchQuery(self, connector, other, self.config)
# On Combinable, these are not implemented to reduce confusion with Q. In
# this case we are actually (ab)using them to do logical combination so
# it's consistent with other usage in Django.
def __or__(self, other):
return self._combine(other, self.BITOR, False)
def __ror__(self, other):
return self._combine(other, self.BITOR, True)
def __and__(self, other):
return self._combine(other, self.BITAND, False)
def __rand__(self, other):
return self._combine(other, self.BITAND, True)
class SearchQuery(SearchQueryCombinable, Func):
output_field = SearchQueryField()
SEARCH_TYPES = {
'plain': 'plainto_tsquery',
'phrase': 'phraseto_tsquery',
'raw': 'to_tsquery',
'websearch': 'websearch_to_tsquery',
}
def __init__(self, value, output_field=None, *, config=None, invert=False, search_type='plain'):
self.function = self.SEARCH_TYPES.get(search_type)
if self.function is None:
raise ValueError("Unknown search_type argument '%s'." % search_type)
if not hasattr(value, 'resolve_expression'):
value = Value(value)
expressions = (value,)
self.config = SearchConfig.from_parameter(config)
if self.config is not None:
expressions = (self.config,) + expressions
self.invert = invert
super().__init__(*expressions, output_field=output_field)
def as_sql(self, compiler, connection, function=None, template=None):
sql, params = super().as_sql(compiler, connection, function, template)
if self.invert:
sql = '!!(%s)' % sql
return sql, params
def __invert__(self):
clone = self.copy()
clone.invert = not self.invert
return clone
def __str__(self):
result = super().__str__()
return ('~%s' % result) if self.invert else result
class CombinedSearchQuery(SearchQueryCombinable, CombinedExpression):
def __init__(self, lhs, connector, rhs, config, output_field=None):
self.config = config
super().__init__(lhs, connector, rhs, output_field)
def __str__(self):
return '(%s)' % super().__str__()
class SearchRank(Func):
function = 'ts_rank'
output_field = FloatField()
def __init__(
self, vector, query, weights=None, normalization=None,
cover_density=False,
):
if not hasattr(vector, 'resolve_expression'):
vector = SearchVector(vector)
if not hasattr(query, 'resolve_expression'):
query = SearchQuery(query)
expressions = (vector, query)
if weights is not None:
if not hasattr(weights, 'resolve_expression'):
weights = Value(weights)
expressions = (weights,) + expressions
if normalization is not None:
if not hasattr(normalization, 'resolve_expression'):
normalization = Value(normalization)
expressions += (normalization,)
if cover_density:
self.function = 'ts_rank_cd'
super().__init__(*expressions)
class SearchHeadline(Func):
function = 'ts_headline'
template = '%(function)s(%(expressions)s%(options)s)'
output_field = TextField()
def __init__(
self, expression, query, *, config=None, start_sel=None, stop_sel=None,
max_words=None, min_words=None, short_word=None, highlight_all=None,
max_fragments=None, fragment_delimiter=None,
):
if not hasattr(query, 'resolve_expression'):
query = SearchQuery(query)
options = {
'StartSel': start_sel,
'StopSel': stop_sel,
'MaxWords': max_words,
'MinWords': min_words,
'ShortWord': short_word,
'HighlightAll': highlight_all,
'MaxFragments': max_fragments,
'FragmentDelimiter': fragment_delimiter,
}
self.options = {
option: value
for option, value in options.items() if value is not None
}
expressions = (expression, query)
if config is not None:
config = SearchConfig.from_parameter(config)
expressions = (config,) + expressions
super().__init__(*expressions)
def as_sql(self, compiler, connection, function=None, template=None):
options_sql = ''
options_params = []
if self.options:
# getquoted() returns a quoted bytestring of the adapted value.
options_params.append(', '.join(
'%s=%s' % (
option,
psycopg2.extensions.adapt(value).getquoted().decode(),
) for option, value in self.options.items()
))
options_sql = ', %s'
sql, params = super().as_sql(
compiler, connection, function=function, template=template,
options=options_sql,
)
return sql, params + options_params
SearchVectorField.register_lookup(SearchVectorExact)
class TrigramBase(Func):
output_field = FloatField()
def __init__(self, expression, string, **extra):
if not hasattr(string, 'resolve_expression'):
string = Value(string)
super().__init__(expression, string, **extra)
class TrigramWordBase(Func):
output_field = FloatField()
def __init__(self, string, expression, **extra):
if not hasattr(string, 'resolve_expression'):
string = Value(string)
super().__init__(string, expression, **extra)
class TrigramSimilarity(TrigramBase):
function = 'SIMILARITY'
class TrigramDistance(TrigramBase):
function = ''
arg_joiner = ' <-> '
class TrigramWordDistance(TrigramWordBase):
function = ''
arg_joiner = ' <<-> '
class TrigramWordSimilarity(TrigramWordBase):
function = 'WORD_SIMILARITY'
|
0a21f9c084c8251dd7227fd5a4afa70b02c9d58acc7717ed0b125bcad5b8e740 | from psycopg2.extras import (
DateRange, DateTimeRange, DateTimeTZRange, NumericRange,
)
from django.apps import AppConfig
from django.core.signals import setting_changed
from django.db import connections
from django.db.backends.signals import connection_created
from django.db.migrations.writer import MigrationWriter
from django.db.models import CharField, OrderBy, TextField
from django.db.models.functions import Collate
from django.db.models.indexes import IndexExpression
from django.utils.translation import gettext_lazy as _
from .indexes import OpClass
from .lookups import SearchLookup, TrigramSimilar, TrigramWordSimilar, Unaccent
from .serializers import RangeSerializer
from .signals import register_type_handlers
RANGE_TYPES = (DateRange, DateTimeRange, DateTimeTZRange, NumericRange)
def uninstall_if_needed(setting, value, enter, **kwargs):
"""
Undo the effects of PostgresConfig.ready() when django.contrib.postgres
is "uninstalled" by override_settings().
"""
if not enter and setting == 'INSTALLED_APPS' and 'django.contrib.postgres' not in set(value):
connection_created.disconnect(register_type_handlers)
CharField._unregister_lookup(Unaccent)
TextField._unregister_lookup(Unaccent)
CharField._unregister_lookup(SearchLookup)
TextField._unregister_lookup(SearchLookup)
CharField._unregister_lookup(TrigramSimilar)
TextField._unregister_lookup(TrigramSimilar)
CharField._unregister_lookup(TrigramWordSimilar)
TextField._unregister_lookup(TrigramWordSimilar)
# Disconnect this receiver until the next time this app is installed
# and ready() connects it again to prevent unnecessary processing on
# each setting change.
setting_changed.disconnect(uninstall_if_needed)
MigrationWriter.unregister_serializer(RANGE_TYPES)
class PostgresConfig(AppConfig):
name = 'django.contrib.postgres'
verbose_name = _('PostgreSQL extensions')
def ready(self):
setting_changed.connect(uninstall_if_needed)
# Connections may already exist before we are called.
for conn in connections.all():
if conn.vendor == 'postgresql':
conn.introspection.data_types_reverse.update({
3904: 'django.contrib.postgres.fields.IntegerRangeField',
3906: 'django.contrib.postgres.fields.DecimalRangeField',
3910: 'django.contrib.postgres.fields.DateTimeRangeField',
3912: 'django.contrib.postgres.fields.DateRangeField',
3926: 'django.contrib.postgres.fields.BigIntegerRangeField',
})
if conn.connection is not None:
register_type_handlers(conn)
connection_created.connect(register_type_handlers)
CharField.register_lookup(Unaccent)
TextField.register_lookup(Unaccent)
CharField.register_lookup(SearchLookup)
TextField.register_lookup(SearchLookup)
CharField.register_lookup(TrigramSimilar)
TextField.register_lookup(TrigramSimilar)
CharField.register_lookup(TrigramWordSimilar)
TextField.register_lookup(TrigramWordSimilar)
MigrationWriter.register_serializer(RANGE_TYPES, RangeSerializer)
IndexExpression.register_wrappers(OrderBy, OpClass, Collate)
|
92477322fbe184b7707379da74497083ae204f2bf9704d036110a260f65085d1 | import functools
import psycopg2
from psycopg2 import ProgrammingError
from psycopg2.extras import register_hstore
from django.db import connections
from django.db.backends.base.base import NO_DB_ALIAS
@functools.lru_cache
def get_hstore_oids(connection_alias):
"""Return hstore and hstore array OIDs."""
with connections[connection_alias].cursor() as cursor:
cursor.execute(
"SELECT t.oid, typarray "
"FROM pg_type t "
"JOIN pg_namespace ns ON typnamespace = ns.oid "
"WHERE typname = 'hstore'"
)
oids = []
array_oids = []
for row in cursor:
oids.append(row[0])
array_oids.append(row[1])
return tuple(oids), tuple(array_oids)
@functools.lru_cache
def get_citext_oids(connection_alias):
"""Return citext array OIDs."""
with connections[connection_alias].cursor() as cursor:
cursor.execute("SELECT typarray FROM pg_type WHERE typname = 'citext'")
return tuple(row[0] for row in cursor)
def register_type_handlers(connection, **kwargs):
if connection.vendor != 'postgresql' or connection.alias == NO_DB_ALIAS:
return
try:
oids, array_oids = get_hstore_oids(connection.alias)
register_hstore(connection.connection, globally=True, oid=oids, array_oid=array_oids)
except ProgrammingError:
# Hstore is not available on the database.
#
# If someone tries to create an hstore field it will error there.
# This is necessary as someone may be using PSQL without extensions
# installed but be using other features of contrib.postgres.
#
# This is also needed in order to create the connection in order to
# install the hstore extension.
pass
try:
citext_oids = get_citext_oids(connection.alias)
array_type = psycopg2.extensions.new_array_type(citext_oids, 'citext[]', psycopg2.STRING)
psycopg2.extensions.register_type(array_type, None)
except ProgrammingError:
# citext is not available on the database.
#
# The same comments in the except block of the above call to
# register_hstore() also apply here.
pass
|
6823a5d74a73d56b11c1e9dd6dc1d9064707f12910841bc68f0068af506b2120 | from django.db.models import Transform
from django.db.models.lookups import PostgresOperatorLookup
from .search import SearchVector, SearchVectorExact, SearchVectorField
class DataContains(PostgresOperatorLookup):
lookup_name = 'contains'
postgres_operator = '@>'
class ContainedBy(PostgresOperatorLookup):
lookup_name = 'contained_by'
postgres_operator = '<@'
class Overlap(PostgresOperatorLookup):
lookup_name = 'overlap'
postgres_operator = '&&'
class HasKey(PostgresOperatorLookup):
lookup_name = 'has_key'
postgres_operator = '?'
prepare_rhs = False
class HasKeys(PostgresOperatorLookup):
lookup_name = 'has_keys'
postgres_operator = '?&'
def get_prep_lookup(self):
return [str(item) for item in self.rhs]
class HasAnyKeys(HasKeys):
lookup_name = 'has_any_keys'
postgres_operator = '?|'
class Unaccent(Transform):
bilateral = True
lookup_name = 'unaccent'
function = 'UNACCENT'
class SearchLookup(SearchVectorExact):
lookup_name = 'search'
def process_lhs(self, qn, connection):
if not isinstance(self.lhs.output_field, SearchVectorField):
config = getattr(self.rhs, 'config', None)
self.lhs = SearchVector(self.lhs, config=config)
lhs, lhs_params = super().process_lhs(qn, connection)
return lhs, lhs_params
class TrigramSimilar(PostgresOperatorLookup):
lookup_name = 'trigram_similar'
postgres_operator = '%%'
class TrigramWordSimilar(PostgresOperatorLookup):
lookup_name = 'trigram_word_similar'
postgres_operator = '%%>'
|
bd71858ad9d426d6ed0288eddb9ffc367d181e2615434560c9d142592a4aef88 | import warnings
from django.contrib.postgres.indexes import OpClass
from django.db import NotSupportedError
from django.db.backends.ddl_references import Expressions, Statement, Table
from django.db.models import Deferrable, F, Q
from django.db.models.constraints import BaseConstraint
from django.db.models.expressions import ExpressionList
from django.db.models.indexes import IndexExpression
from django.db.models.sql import Query
from django.utils.deprecation import RemovedInDjango50Warning
__all__ = ['ExclusionConstraint']
class ExclusionConstraintExpression(IndexExpression):
template = '%(expressions)s WITH %(operator)s'
class ExclusionConstraint(BaseConstraint):
template = 'CONSTRAINT %(name)s EXCLUDE USING %(index_type)s (%(expressions)s)%(include)s%(where)s%(deferrable)s'
def __init__(
self, *, name, expressions, index_type=None, condition=None,
deferrable=None, include=None, opclasses=(),
):
if index_type and index_type.lower() not in {'gist', 'spgist'}:
raise ValueError(
'Exclusion constraints only support GiST or SP-GiST indexes.'
)
if not expressions:
raise ValueError(
'At least one expression is required to define an exclusion '
'constraint.'
)
if not all(
isinstance(expr, (list, tuple)) and len(expr) == 2
for expr in expressions
):
raise ValueError('The expressions must be a list of 2-tuples.')
if not isinstance(condition, (type(None), Q)):
raise ValueError(
'ExclusionConstraint.condition must be a Q instance.'
)
if condition and deferrable:
raise ValueError(
'ExclusionConstraint with conditions cannot be deferred.'
)
if not isinstance(deferrable, (type(None), Deferrable)):
raise ValueError(
'ExclusionConstraint.deferrable must be a Deferrable instance.'
)
if not isinstance(include, (type(None), list, tuple)):
raise ValueError(
'ExclusionConstraint.include must be a list or tuple.'
)
if not isinstance(opclasses, (list, tuple)):
raise ValueError(
'ExclusionConstraint.opclasses must be a list or tuple.'
)
if opclasses and len(expressions) != len(opclasses):
raise ValueError(
'ExclusionConstraint.expressions and '
'ExclusionConstraint.opclasses must have the same number of '
'elements.'
)
self.expressions = expressions
self.index_type = index_type or 'GIST'
self.condition = condition
self.deferrable = deferrable
self.include = tuple(include) if include else ()
self.opclasses = opclasses
if self.opclasses:
warnings.warn(
'The opclasses argument is deprecated in favor of using '
'django.contrib.postgres.indexes.OpClass in '
'ExclusionConstraint.expressions.',
category=RemovedInDjango50Warning,
stacklevel=2,
)
super().__init__(name=name)
def _get_expressions(self, schema_editor, query):
expressions = []
for idx, (expression, operator) in enumerate(self.expressions):
if isinstance(expression, str):
expression = F(expression)
try:
expression = OpClass(expression, self.opclasses[idx])
except IndexError:
pass
expression = ExclusionConstraintExpression(expression, operator=operator)
expression.set_wrapper_classes(schema_editor.connection)
expressions.append(expression)
return ExpressionList(*expressions).resolve_expression(query)
def _get_condition_sql(self, compiler, schema_editor, query):
if self.condition is None:
return None
where = query.build_where(self.condition)
sql, params = where.as_sql(compiler, schema_editor.connection)
return sql % tuple(schema_editor.quote_value(p) for p in params)
def constraint_sql(self, model, schema_editor):
query = Query(model, alias_cols=False)
compiler = query.get_compiler(connection=schema_editor.connection)
expressions = self._get_expressions(schema_editor, query)
table = model._meta.db_table
condition = self._get_condition_sql(compiler, schema_editor, query)
include = [model._meta.get_field(field_name).column for field_name in self.include]
return Statement(
self.template,
table=Table(table, schema_editor.quote_name),
name=schema_editor.quote_name(self.name),
index_type=self.index_type,
expressions=Expressions(table, expressions, compiler, schema_editor.quote_value),
where=' WHERE (%s)' % condition if condition else '',
include=schema_editor._index_include_sql(model, include),
deferrable=schema_editor._deferrable_constraint_sql(self.deferrable),
)
def create_sql(self, model, schema_editor):
self.check_supported(schema_editor)
return Statement(
'ALTER TABLE %(table)s ADD %(constraint)s',
table=Table(model._meta.db_table, schema_editor.quote_name),
constraint=self.constraint_sql(model, schema_editor),
)
def remove_sql(self, model, schema_editor):
return schema_editor._delete_constraint_sql(
schema_editor.sql_delete_check,
model,
schema_editor.quote_name(self.name),
)
def check_supported(self, schema_editor):
if (
self.include and
self.index_type.lower() == 'gist' and
not schema_editor.connection.features.supports_covering_gist_indexes
):
raise NotSupportedError(
'Covering exclusion constraints using a GiST index require '
'PostgreSQL 12+.'
)
if (
self.include and
self.index_type.lower() == 'spgist' and
not schema_editor.connection.features.supports_covering_spgist_indexes
):
raise NotSupportedError(
'Covering exclusion constraints using an SP-GiST index '
'require PostgreSQL 14+.'
)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
kwargs['expressions'] = self.expressions
if self.condition is not None:
kwargs['condition'] = self.condition
if self.index_type.lower() != 'gist':
kwargs['index_type'] = self.index_type
if self.deferrable:
kwargs['deferrable'] = self.deferrable
if self.include:
kwargs['include'] = self.include
if self.opclasses:
kwargs['opclasses'] = self.opclasses
return path, args, kwargs
def __eq__(self, other):
if isinstance(other, self.__class__):
return (
self.name == other.name and
self.index_type == other.index_type and
self.expressions == other.expressions and
self.condition == other.condition and
self.deferrable == other.deferrable and
self.include == other.include and
self.opclasses == other.opclasses
)
return super().__eq__(other)
def __repr__(self):
return '<%s: index_type=%s expressions=%s name=%s%s%s%s%s>' % (
self.__class__.__qualname__,
repr(self.index_type),
repr(self.expressions),
repr(self.name),
'' if self.condition is None else ' condition=%s' % self.condition,
'' if self.deferrable is None else ' deferrable=%r' % self.deferrable,
'' if not self.include else ' include=%s' % repr(self.include),
'' if not self.opclasses else ' opclasses=%s' % repr(self.opclasses),
)
|
3997190954903d5b5f7bc8237a174c1c67c4af4d11275bfada54269a04e1f141 | from django.contrib.auth import get_user_model
from django.contrib.auth.models import Permission
from django.db.models import Exists, OuterRef, Q
UserModel = get_user_model()
class BaseBackend:
def authenticate(self, request, **kwargs):
return None
def get_user(self, user_id):
return None
def get_user_permissions(self, user_obj, obj=None):
return set()
def get_group_permissions(self, user_obj, obj=None):
return set()
def get_all_permissions(self, user_obj, obj=None):
return {
*self.get_user_permissions(user_obj, obj=obj),
*self.get_group_permissions(user_obj, obj=obj),
}
def has_perm(self, user_obj, perm, obj=None):
return perm in self.get_all_permissions(user_obj, obj=obj)
class ModelBackend(BaseBackend):
"""
Authenticates against settings.AUTH_USER_MODEL.
"""
def authenticate(self, request, username=None, password=None, **kwargs):
if username is None:
username = kwargs.get(UserModel.USERNAME_FIELD)
if username is None or password is None:
return
try:
user = UserModel._default_manager.get_by_natural_key(username)
except UserModel.DoesNotExist:
# Run the default password hasher once to reduce the timing
# difference between an existing and a nonexistent user (#20760).
UserModel().set_password(password)
else:
if user.check_password(password) and self.user_can_authenticate(user):
return user
def user_can_authenticate(self, user):
"""
Reject users with is_active=False. Custom user models that don't have
that attribute are allowed.
"""
is_active = getattr(user, 'is_active', None)
return is_active or is_active is None
def _get_user_permissions(self, user_obj):
return user_obj.user_permissions.all()
def _get_group_permissions(self, user_obj):
user_groups_field = get_user_model()._meta.get_field('groups')
user_groups_query = 'group__%s' % user_groups_field.related_query_name()
return Permission.objects.filter(**{user_groups_query: user_obj})
def _get_permissions(self, user_obj, obj, from_name):
"""
Return the permissions of `user_obj` from `from_name`. `from_name` can
be either "group" or "user" to return permissions from
`_get_group_permissions` or `_get_user_permissions` respectively.
"""
if not user_obj.is_active or user_obj.is_anonymous or obj is not None:
return set()
perm_cache_name = '_%s_perm_cache' % from_name
if not hasattr(user_obj, perm_cache_name):
if user_obj.is_superuser:
perms = Permission.objects.all()
else:
perms = getattr(self, '_get_%s_permissions' % from_name)(user_obj)
perms = perms.values_list('content_type__app_label', 'codename').order_by()
setattr(user_obj, perm_cache_name, {"%s.%s" % (ct, name) for ct, name in perms})
return getattr(user_obj, perm_cache_name)
def get_user_permissions(self, user_obj, obj=None):
"""
Return a set of permission strings the user `user_obj` has from their
`user_permissions`.
"""
return self._get_permissions(user_obj, obj, 'user')
def get_group_permissions(self, user_obj, obj=None):
"""
Return a set of permission strings the user `user_obj` has from the
groups they belong.
"""
return self._get_permissions(user_obj, obj, 'group')
def get_all_permissions(self, user_obj, obj=None):
if not user_obj.is_active or user_obj.is_anonymous or obj is not None:
return set()
if not hasattr(user_obj, '_perm_cache'):
user_obj._perm_cache = super().get_all_permissions(user_obj)
return user_obj._perm_cache
def has_perm(self, user_obj, perm, obj=None):
return user_obj.is_active and super().has_perm(user_obj, perm, obj=obj)
def has_module_perms(self, user_obj, app_label):
"""
Return True if user_obj has any permissions in the given app_label.
"""
return user_obj.is_active and any(
perm[:perm.index('.')] == app_label
for perm in self.get_all_permissions(user_obj)
)
def with_perm(self, perm, is_active=True, include_superusers=True, obj=None):
"""
Return users that have permission "perm". By default, filter out
inactive users and include superusers.
"""
if isinstance(perm, str):
try:
app_label, codename = perm.split('.')
except ValueError:
raise ValueError(
'Permission name should be in the form '
'app_label.permission_codename.'
)
elif not isinstance(perm, Permission):
raise TypeError(
'The `perm` argument must be a string or a permission instance.'
)
if obj is not None:
return UserModel._default_manager.none()
permission_q = Q(group__user=OuterRef('pk')) | Q(user=OuterRef('pk'))
if isinstance(perm, Permission):
permission_q &= Q(pk=perm.pk)
else:
permission_q &= Q(codename=codename, content_type__app_label=app_label)
user_q = Exists(Permission.objects.filter(permission_q))
if include_superusers:
user_q |= Q(is_superuser=True)
if is_active is not None:
user_q &= Q(is_active=is_active)
return UserModel._default_manager.filter(user_q)
def get_user(self, user_id):
try:
user = UserModel._default_manager.get(pk=user_id)
except UserModel.DoesNotExist:
return None
return user if self.user_can_authenticate(user) else None
class AllowAllUsersModelBackend(ModelBackend):
def user_can_authenticate(self, user):
return True
class RemoteUserBackend(ModelBackend):
"""
This backend is to be used in conjunction with the ``RemoteUserMiddleware``
found in the middleware module of this package, and is used when the server
is handling authentication outside of Django.
By default, the ``authenticate`` method creates ``User`` objects for
usernames that don't already exist in the database. Subclasses can disable
this behavior by setting the ``create_unknown_user`` attribute to
``False``.
"""
# Create a User object if not already in the database?
create_unknown_user = True
def authenticate(self, request, remote_user):
"""
The username passed as ``remote_user`` is considered trusted. Return
the ``User`` object with the given username. Create a new ``User``
object if ``create_unknown_user`` is ``True``.
Return None if ``create_unknown_user`` is ``False`` and a ``User``
object with the given username is not found in the database.
"""
if not remote_user:
return
user = None
username = self.clean_username(remote_user)
# Note that this could be accomplished in one try-except clause, but
# instead we use get_or_create when creating unknown users since it has
# built-in safeguards for multiple threads.
if self.create_unknown_user:
user, created = UserModel._default_manager.get_or_create(**{
UserModel.USERNAME_FIELD: username
})
if created:
user = self.configure_user(request, user)
else:
try:
user = UserModel._default_manager.get_by_natural_key(username)
except UserModel.DoesNotExist:
pass
return user if self.user_can_authenticate(user) else None
def clean_username(self, username):
"""
Perform any cleaning on the "username" prior to using it to get or
create the user object. Return the cleaned username.
By default, return the username unchanged.
"""
return username
def configure_user(self, request, user):
"""
Configure a user after creation and return the updated user.
By default, return the user unmodified.
"""
return user
class AllowAllUsersRemoteUserBackend(RemoteUserBackend):
def user_can_authenticate(self, user):
return True
|
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