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882f736072a984c6929e5b8165f62f1f5915e5a0f2977c9cb2a563c4ea2a7ce6 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'd F Y'
TIME_FORMAT = 'H:i'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd.m.Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = ' ' # Non-breaking space
# NUMBER_GROUPING =
|
69275dabb7e194e71edf304b753343400e4bfe07c086c98a442bb243c3b94f26 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'g:i A'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j M Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
# DECIMAL_SEPARATOR =
# THOUSAND_SEPARATOR =
# NUMBER_GROUPING =
|
4b611c2c83cc6d5c51b969d1cd6a7647b57321505a6b8b7a5ea9624c82f03382 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'Y년 n월 j일'
TIME_FORMAT = 'A g:i'
DATETIME_FORMAT = 'Y년 n월 j일 g:i A'
YEAR_MONTH_FORMAT = 'Y년 n월'
MONTH_DAY_FORMAT = 'n월 j일'
SHORT_DATE_FORMAT = 'Y-n-j.'
SHORT_DATETIME_FORMAT = 'Y-n-j H:i'
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
# Kept ISO formats as they are in first position
DATE_INPUT_FORMATS = [
'%Y-%m-%d', '%m/%d/%Y', '%m/%d/%y', # '2006-10-25', '10/25/2006', '10/25/06'
# '%b %d %Y', '%b %d, %Y', # 'Oct 25 2006', 'Oct 25, 2006'
# '%d %b %Y', '%d %b, %Y', # '25 Oct 2006', '25 Oct, 2006'
# '%B %d %Y', '%B %d, %Y', # 'October 25 2006', 'October 25, 2006'
# '%d %B %Y', '%d %B, %Y', # '25 October 2006', '25 October, 2006'
'%Y년 %m월 %d일', # '2006년 10월 25일', with localized suffix.
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # '14:30:59'
'%H:%M:%S.%f', # '14:30:59.000200'
'%H:%M', # '14:30'
'%H시 %M분 %S초', # '14시 30분 59초'
'%H시 %M분', # '14시 30분'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
'%m/%d/%Y %H:%M:%S', # '10/25/2006 14:30:59'
'%m/%d/%Y %H:%M:%S.%f', # '10/25/2006 14:30:59.000200'
'%m/%d/%Y %H:%M', # '10/25/2006 14:30'
'%m/%d/%Y', # '10/25/2006'
'%m/%d/%y %H:%M:%S', # '10/25/06 14:30:59'
'%m/%d/%y %H:%M:%S.%f', # '10/25/06 14:30:59.000200'
'%m/%d/%y %H:%M', # '10/25/06 14:30'
'%m/%d/%y', # '10/25/06'
'%Y년 %m월 %d일 %H시 %M분 %S초', # '2006년 10월 25일 14시 30분 59초'
'%Y년 %m월 %d일 %H시 %M분', # '2006년 10월 25일 14시 30분'
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
7dc6ce68d9a84165393bced8b2f885b2a435497691674a29b02be0ca00a496a1 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j F Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j N Y'
SHORT_DATETIME_FORMAT = 'j N Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', '%d/%m/%y', # '25/10/2006', '25/10/06'
'%d.%m.%Y', '%d.%m.%y', # Swiss [fr_CH), '25.10.2006', '25.10.06'
# '%d %B %Y', '%d %b %Y', # '25 octobre 2006', '25 oct. 2006'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S', # '25/10/2006 14:30:59'
'%d/%m/%Y %H:%M:%S.%f', # '25/10/2006 14:30:59.000200'
'%d/%m/%Y %H:%M', # '25/10/2006 14:30'
'%d/%m/%Y', # '25/10/2006'
'%d.%m.%Y %H:%M:%S', # Swiss [fr_CH), '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # Swiss (fr_CH), '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # Swiss (fr_CH), '25.10.2006 14:30'
'%d.%m.%Y', # Swiss (fr_CH), '25.10.2006'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
bc11ac3ed31990964dd2055c5f77820d5137287b23249f78116dbff6d093d16e | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = 'j F Y, G:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j M Y'
SHORT_DATETIME_FORMAT = 'j M Y, G:i'
FIRST_DAY_OF_WEEK = 0 # Sunday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', # 25/10/2006
'%d %b %Y', # 25 ต.ค. 2006
'%d %B %Y', # 25 ตุลาคม 2006
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # 14:30:59
'%H:%M:%S.%f', # 14:30:59.000200
'%H:%M', # 14:30
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S', # 25/10/2006 14:30:59
'%d/%m/%Y %H:%M:%S.%f', # 25/10/2006 14:30:59.000200
'%d/%m/%Y %H:%M', # 25/10/2006 14:30
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
36877396bb40ebfd24edb982b3a6bdf938e102b88665c4d3d76335f9a37e8fee | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'Y. \g\a\d\a j. F'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'Y. \g\a\d\a j. F, H:i'
YEAR_MONTH_FORMAT = r'Y. \g. F'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = r'j.m.Y'
SHORT_DATETIME_FORMAT = 'j.m.Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
# Kept ISO formats as they are in first position
DATE_INPUT_FORMATS = [
'%Y-%m-%d', '%d.%m.%Y', '%d.%m.%y', # '2006-10-25', '25.10.2006', '25.10.06'
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # '14:30:59'
'%H:%M:%S.%f', # '14:30:59.000200'
'%H:%M', # '14:30'
'%H.%M.%S', # '14.30.59'
'%H.%M.%S.%f', # '14.30.59.000200'
'%H.%M', # '14.30'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y %H:%M:%S', # '25.10.06 14:30:59'
'%d.%m.%y %H:%M:%S.%f', # '25.10.06 14:30:59.000200'
'%d.%m.%y %H:%M', # '25.10.06 14:30'
'%d.%m.%y %H.%M.%S', # '25.10.06 14.30.59'
'%d.%m.%y %H.%M.%S.%f', # '25.10.06 14.30.59.000200'
'%d.%m.%y %H.%M', # '25.10.06 14.30'
'%d.%m.%y', # '25.10.06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = ' ' # Non-breaking space
NUMBER_GROUPING = 3
|
8eab84ead2e3f673b1706b47ff7dbac39eec1fd04a84fe012ad3f3e9e0a2e24f | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. F Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j. F Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'd.m.Y'
SHORT_DATETIME_FORMAT = 'd.m.Y H:i'
FIRST_DAY_OF_WEEK = 1
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d.%m.%Y', # '25.10.2006'
]
DATETIME_INPUT_FORMATS = [
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
74163426f5a29c678d883cb866b9ebb4f69941dc14ec9ba09331c4db60be3340 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'g:i A'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd-m-Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
# NUMBER_GROUPING =
|
c0ce3bfa097a3765db927308500bcd9aac4dcaca3a6cd9f0535d51ce82cadd13 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see https://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j E Y г.'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = 'j E Y г. G:i'
YEAR_MONTH_FORMAT = 'F Y г.'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd.m.Y'
SHORT_DATETIME_FORMAT = 'd.m.Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see https://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y', # '25.10.06'
]
DATETIME_INPUT_FORMATS = [
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y %H:%M:%S', # '25.10.06 14:30:59'
'%d.%m.%y %H:%M:%S.%f', # '25.10.06 14:30:59.000200'
'%d.%m.%y %H:%M', # '25.10.06 14:30'
'%d.%m.%y', # '25.10.06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
8e84622a5fc44c894b78a46c77fe09a645f41269643bf2e5eb355324362be694 | """Translation helper functions."""
import functools
import gettext as gettext_module
import os
import re
import sys
import warnings
from threading import local
from django.apps import apps
from django.conf import settings
from django.conf.locale import LANG_INFO
from django.core.exceptions import AppRegistryNotReady
from django.core.signals import setting_changed
from django.dispatch import receiver
from django.utils.safestring import SafeData, mark_safe
from . import to_language, to_locale
# Translations are cached in a dictionary for every language.
# The active translations are stored by threadid to make them thread local.
_translations = {}
_active = local()
# The default translation is based on the settings file.
_default = None
# magic gettext number to separate context from message
CONTEXT_SEPARATOR = "\x04"
# Format of Accept-Language header values. From RFC 2616, section 14.4 and 3.9
# and RFC 3066, section 2.1
accept_language_re = re.compile(r'''
([A-Za-z]{1,8}(?:-[A-Za-z0-9]{1,8})*|\*) # "en", "en-au", "x-y-z", "es-419", "*"
(?:\s*;\s*q=(0(?:\.\d{,3})?|1(?:\.0{,3})?))? # Optional "q=1.00", "q=0.8"
(?:\s*,\s*|$) # Multiple accepts per header.
''', re.VERBOSE)
language_code_re = re.compile(
r'^[a-z]{1,8}(?:-[a-z0-9]{1,8})*(?:@[a-z0-9]{1,20})?$',
re.IGNORECASE
)
language_code_prefix_re = re.compile(r'^/(\w+([@-]\w+)?)(/|$)')
@receiver(setting_changed)
def reset_cache(**kwargs):
"""
Reset global state when LANGUAGES setting has been changed, as some
languages should no longer be accepted.
"""
if kwargs['setting'] in ('LANGUAGES', 'LANGUAGE_CODE'):
check_for_language.cache_clear()
get_languages.cache_clear()
get_supported_language_variant.cache_clear()
class DjangoTranslation(gettext_module.GNUTranslations):
"""
Set up the GNUTranslations context with regard to output charset.
This translation object will be constructed out of multiple GNUTranslations
objects by merging their catalogs. It will construct an object for the
requested language and add a fallback to the default language, if it's
different from the requested language.
"""
domain = 'django'
def __init__(self, language, domain=None, localedirs=None):
"""Create a GNUTranslations() using many locale directories"""
gettext_module.GNUTranslations.__init__(self)
if domain is not None:
self.domain = domain
self.__language = language
self.__to_language = to_language(language)
self.__locale = to_locale(language)
self._catalog = None
# If a language doesn't have a catalog, use the Germanic default for
# pluralization: anything except one is pluralized.
self.plural = lambda n: int(n != 1)
if self.domain == 'django':
if localedirs is not None:
# A module-level cache is used for caching 'django' translations
warnings.warn("localedirs is ignored when domain is 'django'.", RuntimeWarning)
localedirs = None
self._init_translation_catalog()
if localedirs:
for localedir in localedirs:
translation = self._new_gnu_trans(localedir)
self.merge(translation)
else:
self._add_installed_apps_translations()
self._add_local_translations()
if self.__language == settings.LANGUAGE_CODE and self.domain == 'django' and self._catalog is None:
# default lang should have at least one translation file available.
raise OSError('No translation files found for default language %s.' % settings.LANGUAGE_CODE)
self._add_fallback(localedirs)
if self._catalog is None:
# No catalogs found for this language, set an empty catalog.
self._catalog = {}
def __repr__(self):
return "<DjangoTranslation lang:%s>" % self.__language
def _new_gnu_trans(self, localedir, use_null_fallback=True):
"""
Return a mergeable gettext.GNUTranslations instance.
A convenience wrapper. By default gettext uses 'fallback=False'.
Using param `use_null_fallback` to avoid confusion with any other
references to 'fallback'.
"""
return gettext_module.translation(
domain=self.domain,
localedir=localedir,
languages=[self.__locale],
fallback=use_null_fallback,
)
def _init_translation_catalog(self):
"""Create a base catalog using global django translations."""
settingsfile = sys.modules[settings.__module__].__file__
localedir = os.path.join(os.path.dirname(settingsfile), 'locale')
translation = self._new_gnu_trans(localedir)
self.merge(translation)
def _add_installed_apps_translations(self):
"""Merge translations from each installed app."""
try:
app_configs = reversed(list(apps.get_app_configs()))
except AppRegistryNotReady:
raise AppRegistryNotReady(
"The translation infrastructure cannot be initialized before the "
"apps registry is ready. Check that you don't make non-lazy "
"gettext calls at import time.")
for app_config in app_configs:
localedir = os.path.join(app_config.path, 'locale')
if os.path.exists(localedir):
translation = self._new_gnu_trans(localedir)
self.merge(translation)
def _add_local_translations(self):
"""Merge translations defined in LOCALE_PATHS."""
for localedir in reversed(settings.LOCALE_PATHS):
translation = self._new_gnu_trans(localedir)
self.merge(translation)
def _add_fallback(self, localedirs=None):
"""Set the GNUTranslations() fallback with the default language."""
# Don't set a fallback for the default language or any English variant
# (as it's empty, so it'll ALWAYS fall back to the default language)
if self.__language == settings.LANGUAGE_CODE or self.__language.startswith('en'):
return
if self.domain == 'django':
# Get from cache
default_translation = translation(settings.LANGUAGE_CODE)
else:
default_translation = DjangoTranslation(
settings.LANGUAGE_CODE, domain=self.domain, localedirs=localedirs
)
self.add_fallback(default_translation)
def merge(self, other):
"""Merge another translation into this catalog."""
if not getattr(other, '_catalog', None):
return # NullTranslations() has no _catalog
if self._catalog is None:
# Take plural and _info from first catalog found (generally Django's).
self.plural = other.plural
self._info = other._info.copy()
self._catalog = other._catalog.copy()
else:
self._catalog.update(other._catalog)
if other._fallback:
self.add_fallback(other._fallback)
def language(self):
"""Return the translation language."""
return self.__language
def to_language(self):
"""Return the translation language name."""
return self.__to_language
def translation(language):
"""
Return a translation object in the default 'django' domain.
"""
global _translations
if language not in _translations:
_translations[language] = DjangoTranslation(language)
return _translations[language]
def activate(language):
"""
Fetch the translation object for a given language and install it as the
current translation object for the current thread.
"""
if not language:
return
_active.value = translation(language)
def deactivate():
"""
Uninstall the active translation object so that further _() calls resolve
to the default translation object.
"""
if hasattr(_active, "value"):
del _active.value
def deactivate_all():
"""
Make the active translation object a NullTranslations() instance. This is
useful when we want delayed translations to appear as the original string
for some reason.
"""
_active.value = gettext_module.NullTranslations()
_active.value.to_language = lambda *args: None
def get_language():
"""Return the currently selected language."""
t = getattr(_active, "value", None)
if t is not None:
try:
return t.to_language()
except AttributeError:
pass
# If we don't have a real translation object, assume it's the default language.
return settings.LANGUAGE_CODE
def get_language_bidi():
"""
Return selected language's BiDi layout.
* False = left-to-right layout
* True = right-to-left layout
"""
lang = get_language()
if lang is None:
return False
else:
base_lang = get_language().split('-')[0]
return base_lang in settings.LANGUAGES_BIDI
def catalog():
"""
Return the current active catalog for further processing.
This can be used if you need to modify the catalog or want to access the
whole message catalog instead of just translating one string.
"""
global _default
t = getattr(_active, "value", None)
if t is not None:
return t
if _default is None:
_default = translation(settings.LANGUAGE_CODE)
return _default
def gettext(message):
"""
Translate the 'message' string. It uses the current thread to find the
translation object to use. If no current translation is activated, the
message will be run through the default translation object.
"""
global _default
eol_message = message.replace('\r\n', '\n').replace('\r', '\n')
if eol_message:
_default = _default or translation(settings.LANGUAGE_CODE)
translation_object = getattr(_active, "value", _default)
result = translation_object.gettext(eol_message)
else:
# Return an empty value of the corresponding type if an empty message
# is given, instead of metadata, which is the default gettext behavior.
result = type(message)('')
if isinstance(message, SafeData):
return mark_safe(result)
return result
def pgettext(context, message):
msg_with_ctxt = "%s%s%s" % (context, CONTEXT_SEPARATOR, message)
result = gettext(msg_with_ctxt)
if CONTEXT_SEPARATOR in result:
# Translation not found
result = message
elif isinstance(message, SafeData):
result = mark_safe(result)
return result
def gettext_noop(message):
"""
Mark strings for translation but don't translate them now. This can be
used to store strings in global variables that should stay in the base
language (because they might be used externally) and will be translated
later.
"""
return message
def do_ntranslate(singular, plural, number, translation_function):
global _default
t = getattr(_active, "value", None)
if t is not None:
return getattr(t, translation_function)(singular, plural, number)
if _default is None:
_default = translation(settings.LANGUAGE_CODE)
return getattr(_default, translation_function)(singular, plural, number)
def ngettext(singular, plural, number):
"""
Return a string of the translation of either the singular or plural,
based on the number.
"""
return do_ntranslate(singular, plural, number, 'ngettext')
def npgettext(context, singular, plural, number):
msgs_with_ctxt = ("%s%s%s" % (context, CONTEXT_SEPARATOR, singular),
"%s%s%s" % (context, CONTEXT_SEPARATOR, plural),
number)
result = ngettext(*msgs_with_ctxt)
if CONTEXT_SEPARATOR in result:
# Translation not found
result = ngettext(singular, plural, number)
return result
def all_locale_paths():
"""
Return a list of paths to user-provides languages files.
"""
globalpath = os.path.join(
os.path.dirname(sys.modules[settings.__module__].__file__), 'locale')
app_paths = []
for app_config in apps.get_app_configs():
locale_path = os.path.join(app_config.path, 'locale')
if os.path.exists(locale_path):
app_paths.append(locale_path)
return [globalpath, *settings.LOCALE_PATHS, *app_paths]
@functools.lru_cache(maxsize=1000)
def check_for_language(lang_code):
"""
Check whether there is a global language file for the given language
code. This is used to decide whether a user-provided language is
available.
lru_cache should have a maxsize to prevent from memory exhaustion attacks,
as the provided language codes are taken from the HTTP request. See also
<https://www.djangoproject.com/weblog/2007/oct/26/security-fix/>.
"""
# First, a quick check to make sure lang_code is well-formed (#21458)
if lang_code is None or not language_code_re.search(lang_code):
return False
return any(
gettext_module.find('django', path, [to_locale(lang_code)]) is not None
for path in all_locale_paths()
)
@functools.lru_cache()
def get_languages():
"""
Cache of settings.LANGUAGES in a dictionary for easy lookups by key.
"""
return dict(settings.LANGUAGES)
@functools.lru_cache(maxsize=1000)
def get_supported_language_variant(lang_code, strict=False):
"""
Return the language code that's listed in supported languages, possibly
selecting a more generic variant. Raise LookupError if nothing is found.
If `strict` is False (the default), look for a country-specific variant
when neither the language code nor its generic variant is found.
lru_cache should have a maxsize to prevent from memory exhaustion attacks,
as the provided language codes are taken from the HTTP request. See also
<https://www.djangoproject.com/weblog/2007/oct/26/security-fix/>.
"""
if lang_code:
# If 'fr-ca' is not supported, try special fallback or language-only 'fr'.
possible_lang_codes = [lang_code]
try:
possible_lang_codes.extend(LANG_INFO[lang_code]['fallback'])
except KeyError:
pass
generic_lang_code = lang_code.split('-')[0]
possible_lang_codes.append(generic_lang_code)
supported_lang_codes = get_languages()
for code in possible_lang_codes:
if code in supported_lang_codes and check_for_language(code):
return code
if not strict:
# if fr-fr is not supported, try fr-ca.
for supported_code in supported_lang_codes:
if supported_code.startswith(generic_lang_code + '-'):
return supported_code
raise LookupError(lang_code)
def get_language_from_path(path, strict=False):
"""
Return the language code if there's a valid language code found in `path`.
If `strict` is False (the default), look for a country-specific variant
when neither the language code nor its generic variant is found.
"""
regex_match = language_code_prefix_re.match(path)
if not regex_match:
return None
lang_code = regex_match.group(1)
try:
return get_supported_language_variant(lang_code, strict=strict)
except LookupError:
return None
def get_language_from_request(request, check_path=False):
"""
Analyze the request to find what language the user wants the system to
show. Only languages listed in settings.LANGUAGES are taken into account.
If the user requests a sublanguage where we have a main language, we send
out the main language.
If check_path is True, the URL path prefix will be checked for a language
code, otherwise this is skipped for backwards compatibility.
"""
if check_path:
lang_code = get_language_from_path(request.path_info)
if lang_code is not None:
return lang_code
lang_code = request.COOKIES.get(settings.LANGUAGE_COOKIE_NAME)
if lang_code is not None and lang_code in get_languages() and check_for_language(lang_code):
return lang_code
try:
return get_supported_language_variant(lang_code)
except LookupError:
pass
accept = request.META.get('HTTP_ACCEPT_LANGUAGE', '')
for accept_lang, unused in parse_accept_lang_header(accept):
if accept_lang == '*':
break
if not language_code_re.search(accept_lang):
continue
try:
return get_supported_language_variant(accept_lang)
except LookupError:
continue
try:
return get_supported_language_variant(settings.LANGUAGE_CODE)
except LookupError:
return settings.LANGUAGE_CODE
@functools.lru_cache(maxsize=1000)
def parse_accept_lang_header(lang_string):
"""
Parse the lang_string, which is the body of an HTTP Accept-Language
header, and return a tuple of (lang, q-value), ordered by 'q' values.
Return an empty tuple if there are any format errors in lang_string.
"""
result = []
pieces = accept_language_re.split(lang_string.lower())
if pieces[-1]:
return ()
for i in range(0, len(pieces) - 1, 3):
first, lang, priority = pieces[i:i + 3]
if first:
return ()
if priority:
priority = float(priority)
else:
priority = 1.0
result.append((lang, priority))
result.sort(key=lambda k: k[1], reverse=True)
return tuple(result)
|
1667e10fee84f3381d1b0ecdad82c57d8dc2ee15dc678ce06a9a6da7cf771e5d | """
Internationalization support.
"""
import re
import warnings
from contextlib import ContextDecorator
from decimal import ROUND_UP, Decimal
from django.utils.autoreload import autoreload_started, file_changed
from django.utils.deprecation import RemovedInDjango40Warning
from django.utils.functional import lazy
__all__ = [
'activate', 'deactivate', 'override', 'deactivate_all',
'get_language', 'get_language_from_request',
'get_language_info', 'get_language_bidi',
'check_for_language', 'to_language', 'to_locale', 'templatize',
'gettext', 'gettext_lazy', 'gettext_noop',
'ugettext', 'ugettext_lazy', 'ugettext_noop',
'ngettext', 'ngettext_lazy',
'ungettext', 'ungettext_lazy',
'pgettext', 'pgettext_lazy',
'npgettext', 'npgettext_lazy',
'LANGUAGE_SESSION_KEY',
]
LANGUAGE_SESSION_KEY = '_language'
class TranslatorCommentWarning(SyntaxWarning):
pass
# Here be dragons, so a short explanation of the logic won't hurt:
# We are trying to solve two problems: (1) access settings, in particular
# settings.USE_I18N, as late as possible, so that modules can be imported
# without having to first configure Django, and (2) if some other code creates
# a reference to one of these functions, don't break that reference when we
# replace the functions with their real counterparts (once we do access the
# settings).
class Trans:
"""
The purpose of this class is to store the actual translation function upon
receiving the first call to that function. After this is done, changes to
USE_I18N will have no effect to which function is served upon request. If
your tests rely on changing USE_I18N, you can delete all the functions
from _trans.__dict__.
Note that storing the function with setattr will have a noticeable
performance effect, as access to the function goes the normal path,
instead of using __getattr__.
"""
def __getattr__(self, real_name):
from django.conf import settings
if settings.USE_I18N:
from django.utils.translation import trans_real as trans
from django.utils.translation.reloader import watch_for_translation_changes, translation_file_changed
autoreload_started.connect(watch_for_translation_changes, dispatch_uid='translation_file_changed')
file_changed.connect(translation_file_changed, dispatch_uid='translation_file_changed')
else:
from django.utils.translation import trans_null as trans
setattr(self, real_name, getattr(trans, real_name))
return getattr(trans, real_name)
_trans = Trans()
# The Trans class is no more needed, so remove it from the namespace.
del Trans
def gettext_noop(message):
return _trans.gettext_noop(message)
def ugettext_noop(message):
"""
A legacy compatibility wrapper for Unicode handling on Python 2.
Alias of gettext_noop() since Django 2.0.
"""
warnings.warn(
'django.utils.translation.ugettext_noop() is deprecated in favor of '
'django.utils.translation.gettext_noop().',
RemovedInDjango40Warning, stacklevel=2,
)
return gettext_noop(message)
def gettext(message):
return _trans.gettext(message)
def ugettext(message):
"""
A legacy compatibility wrapper for Unicode handling on Python 2.
Alias of gettext() since Django 2.0.
"""
warnings.warn(
'django.utils.translation.ugettext() is deprecated in favor of '
'django.utils.translation.gettext().',
RemovedInDjango40Warning, stacklevel=2,
)
return gettext(message)
def ngettext(singular, plural, number):
return _trans.ngettext(singular, plural, number)
def ungettext(singular, plural, number):
"""
A legacy compatibility wrapper for Unicode handling on Python 2.
Alias of ngettext() since Django 2.0.
"""
warnings.warn(
'django.utils.translation.ungettext() is deprecated in favor of '
'django.utils.translation.ngettext().',
RemovedInDjango40Warning, stacklevel=2,
)
return ngettext(singular, plural, number)
def pgettext(context, message):
return _trans.pgettext(context, message)
def npgettext(context, singular, plural, number):
return _trans.npgettext(context, singular, plural, number)
gettext_lazy = lazy(gettext, str)
pgettext_lazy = lazy(pgettext, str)
def ugettext_lazy(message):
"""
A legacy compatibility wrapper for Unicode handling on Python 2. Has been
Alias of gettext_lazy since Django 2.0.
"""
warnings.warn(
'django.utils.translation.ugettext_lazy() is deprecated in favor of '
'django.utils.translation.gettext_lazy().',
RemovedInDjango40Warning, stacklevel=2,
)
return gettext_lazy(message)
def lazy_number(func, resultclass, number=None, **kwargs):
if isinstance(number, int):
kwargs['number'] = number
proxy = lazy(func, resultclass)(**kwargs)
else:
original_kwargs = kwargs.copy()
class NumberAwareString(resultclass):
def __bool__(self):
return bool(kwargs['singular'])
def _get_number_value(self, values):
try:
return values[number]
except KeyError:
raise KeyError(
"Your dictionary lacks key '%s\'. Please provide "
"it, because it is required to determine whether "
"string is singular or plural." % number
)
def _translate(self, number_value):
kwargs['number'] = number_value
return func(**kwargs)
def format(self, *args, **kwargs):
number_value = self._get_number_value(kwargs) if kwargs and number else args[0]
return self._translate(number_value).format(*args, **kwargs)
def __mod__(self, rhs):
if isinstance(rhs, dict) and number:
number_value = self._get_number_value(rhs)
else:
number_value = rhs
translated = self._translate(number_value)
try:
translated = translated % rhs
except TypeError:
# String doesn't contain a placeholder for the number.
pass
return translated
proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs))
return proxy
def _lazy_number_unpickle(func, resultclass, number, kwargs):
return lazy_number(func, resultclass, number=number, **kwargs)
def ngettext_lazy(singular, plural, number=None):
return lazy_number(ngettext, str, singular=singular, plural=plural, number=number)
def ungettext_lazy(singular, plural, number=None):
"""
A legacy compatibility wrapper for Unicode handling on Python 2.
An alias of ungettext_lazy() since Django 2.0.
"""
warnings.warn(
'django.utils.translation.ungettext_lazy() is deprecated in favor of '
'django.utils.translation.ngettext_lazy().',
RemovedInDjango40Warning, stacklevel=2,
)
return ngettext_lazy(singular, plural, number)
def npgettext_lazy(context, singular, plural, number=None):
return lazy_number(npgettext, str, context=context, singular=singular, plural=plural, number=number)
def activate(language):
return _trans.activate(language)
def deactivate():
return _trans.deactivate()
class override(ContextDecorator):
def __init__(self, language, deactivate=False):
self.language = language
self.deactivate = deactivate
def __enter__(self):
self.old_language = get_language()
if self.language is not None:
activate(self.language)
else:
deactivate_all()
def __exit__(self, exc_type, exc_value, traceback):
if self.old_language is None:
deactivate_all()
elif self.deactivate:
deactivate()
else:
activate(self.old_language)
def get_language():
return _trans.get_language()
def get_language_bidi():
return _trans.get_language_bidi()
def check_for_language(lang_code):
return _trans.check_for_language(lang_code)
def to_language(locale):
"""Turn a locale name (en_US) into a language name (en-us)."""
p = locale.find('_')
if p >= 0:
return locale[:p].lower() + '-' + locale[p + 1:].lower()
else:
return locale.lower()
def to_locale(language):
"""Turn a language name (en-us) into a locale name (en_US)."""
language, _, country = language.lower().partition('-')
if not country:
return language
# A language with > 2 characters after the dash only has its first
# character after the dash capitalized; e.g. sr-latn becomes sr_Latn.
# A language with 2 characters after the dash has both characters
# capitalized; e.g. en-us becomes en_US.
country, _, tail = country.partition('-')
country = country.title() if len(country) > 2 else country.upper()
if tail:
country += '-' + tail
return language + '_' + country
def get_language_from_request(request, check_path=False):
return _trans.get_language_from_request(request, check_path)
def get_language_from_path(path):
return _trans.get_language_from_path(path)
def get_supported_language_variant(lang_code, *, strict=False):
return _trans.get_supported_language_variant(lang_code, strict)
def templatize(src, **kwargs):
from .template import templatize
return templatize(src, **kwargs)
def deactivate_all():
return _trans.deactivate_all()
def get_language_info(lang_code):
from django.conf.locale import LANG_INFO
try:
lang_info = LANG_INFO[lang_code]
if 'fallback' in lang_info and 'name' not in lang_info:
info = get_language_info(lang_info['fallback'][0])
else:
info = lang_info
except KeyError:
if '-' not in lang_code:
raise KeyError("Unknown language code %s." % lang_code)
generic_lang_code = lang_code.split('-')[0]
try:
info = LANG_INFO[generic_lang_code]
except KeyError:
raise KeyError("Unknown language code %s and %s." % (lang_code, generic_lang_code))
if info:
info['name_translated'] = gettext_lazy(info['name'])
return info
trim_whitespace_re = re.compile(r'\s*\n\s*')
def trim_whitespace(s):
return trim_whitespace_re.sub(' ', s.strip())
def round_away_from_one(value):
return int(Decimal(value - 1).quantize(Decimal('0'), rounding=ROUND_UP)) + 1
|
fdd786f73b8593990f6797314ef6fbde174ccc596f41ef821875cce49fa8dcd6 | import threading
from pathlib import Path
from django.apps import apps
def watch_for_translation_changes(sender, **kwargs):
"""Register file watchers for .mo files in potential locale paths."""
from django.conf import settings
if settings.USE_I18N:
directories = [Path('locale')]
directories.extend(Path(config.path) / 'locale' for config in apps.get_app_configs())
directories.extend(Path(p) for p in settings.LOCALE_PATHS)
for path in directories:
absolute_path = path.absolute()
sender.watch_dir(absolute_path, '**/*.mo')
def translation_file_changed(sender, file_path, **kwargs):
"""Clear the internal translations cache if a .mo file is modified."""
if file_path.suffix == '.mo':
import gettext
from django.utils.translation import trans_real
gettext._translations = {}
trans_real._translations = {}
trans_real._default = None
trans_real._active = threading.local()
return True
|
54d851117515df835e4895f05ef419c2f0bb68cd21aa46552c40124fe36df9cc | """
Wrapper class that takes a list of template loaders as an argument and attempts
to load templates from them in order, caching the result.
"""
import hashlib
from django.template import TemplateDoesNotExist
from django.template.backends.django import copy_exception
from .base import Loader as BaseLoader
class Loader(BaseLoader):
def __init__(self, engine, loaders):
self.get_template_cache = {}
self.loaders = engine.get_template_loaders(loaders)
super().__init__(engine)
def get_contents(self, origin):
return origin.loader.get_contents(origin)
def get_template(self, template_name, skip=None):
"""
Perform the caching that gives this loader its name. Often many of the
templates attempted will be missing, so memory use is of concern here.
To keep it in check, caching behavior is a little complicated when a
template is not found. See ticket #26306 for more details.
With template debugging disabled, cache the TemplateDoesNotExist class
for every missing template and raise a new instance of it after
fetching it from the cache.
With template debugging enabled, a unique TemplateDoesNotExist object
is cached for each missing template to preserve debug data. When
raising an exception, Python sets __traceback__, __context__, and
__cause__ attributes on it. Those attributes can contain references to
all sorts of objects up the call chain and caching them creates a
memory leak. Thus, unraised copies of the exceptions are cached and
copies of those copies are raised after they're fetched from the cache.
"""
key = self.cache_key(template_name, skip)
cached = self.get_template_cache.get(key)
if cached:
if isinstance(cached, type) and issubclass(cached, TemplateDoesNotExist):
raise cached(template_name)
elif isinstance(cached, TemplateDoesNotExist):
raise copy_exception(cached)
return cached
try:
template = super().get_template(template_name, skip)
except TemplateDoesNotExist as e:
self.get_template_cache[key] = copy_exception(e) if self.engine.debug else TemplateDoesNotExist
raise
else:
self.get_template_cache[key] = template
return template
def get_template_sources(self, template_name):
for loader in self.loaders:
yield from loader.get_template_sources(template_name)
def cache_key(self, template_name, skip=None):
"""
Generate a cache key for the template name and skip.
If skip is provided, only origins that match template_name are included
in the cache key. This ensures each template is only parsed and cached
once if contained in different extend chains like:
x -> a -> a
y -> a -> a
z -> a -> a
"""
skip_prefix = ''
if skip:
matching = [origin.name for origin in skip if origin.template_name == template_name]
if matching:
skip_prefix = self.generate_hash(matching)
return '-'.join(s for s in (str(template_name), skip_prefix) if s)
def generate_hash(self, values):
return hashlib.sha1('|'.join(values).encode()).hexdigest()
def reset(self):
"Empty the template cache."
self.get_template_cache.clear()
|
34e4455a4fedcf522c5fa58d6633fb233e40cfa5fca543f476605f342e2fa1d9 | from django.middleware.csrf import get_token
from django.utils.functional import lazy
from django.utils.html import format_html
from django.utils.safestring import SafeString
def csrf_input(request):
return format_html(
'<input type="hidden" name="csrfmiddlewaretoken" value="{}">',
get_token(request))
csrf_input_lazy = lazy(csrf_input, SafeString, str)
csrf_token_lazy = lazy(get_token, str)
|
7d4f59cc50e48aa3151d1fe3e1f9f3168196ec56b01ebfd0240fe4662b585909 | 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:
# 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=list(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.
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 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.loader.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
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)
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, record individual statuses
if migration.replaces:
for app_label, name in migration.replaces:
self.recorder.record_unapplied(app_label, name)
else:
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
with self.connection.cursor() as cursor:
existing_table_names = self.connection.introspection.table_names(cursor)
# 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
if model._meta.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:
if field.remote_field.through._meta.db_table not in existing_table_names:
return False, project_state
else:
found_add_field_migration = True
continue
column_names = [
column.name for column in
self.connection.introspection.get_table_description(self.connection.cursor(), table)
]
if field.column not in column_names:
return False, project_state
found_add_field_migration = True
# 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
|
0a04b4ba21b4b2167851de1668632349dc12bd3f18d105b66b3a7485473874c4 | import copy
from contextlib import contextmanager
from django.apps import AppConfig
from django.apps.registry import Apps, apps as global_apps
from django.conf import settings
from django.db import models
from django.db.models.fields.proxy import OrderWrt
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
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
self.real_apps = real_apps or []
self.is_delayed = False
def add_model(self, model_state):
app_label, model_name = model_state.app_label, model_state.name_lower
self.models[(app_label, model_name)] = model_state
if 'apps' in self.__dict__: # hasattr would cache the property
self.reload_model(app_label, model_name)
def remove_model(self, app_label, model_name):
del self.models[app_label, model_name]
if 'apps' in self.__dict__: # hasattr would cache the property
self.apps.unregister_model(app_label, model_name)
# Need to do this explicitly since unregister_model() doesn't clear
# the cache automatically (#24513)
self.apps.clear_cache()
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 name, field in model_state.fields:
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 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)
@property
def concrete_apps(self):
self.apps = StateApps(self.real_apps, self.models, ignore_swappable=True)
return self.apps
@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 set(self.real_apps) == set(other.real_apps)
class AppConfigStub(AppConfig):
"""Stub of an AppConfig. Only provides a label and a dict of models."""
# Not used, but required by AppConfig.__init__
path = ''
def __init__(self, label):
self.label = label
# 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.
super().__init__(label, None)
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 = {}
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 = fields
self.options = options or {}
self.options.setdefault('indexes', [])
self.options.setdefault('constraints', [])
self.bases = bases or (models.Model,)
self.managers = managers or []
# Sanity-check that fields is NOT a dict. It must be ordered.
if isinstance(self.fields, dict):
raise ValueError("ModelState.fields cannot be a dict - it must be a list of 2-tuples.")
for name, field in fields:
# 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()
@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, 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=list(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,))
# Turn fields into a dict for the body, add other bits
body = {name: field.clone() for name, field in self.fields}
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_field_by_name(self, name):
for fname, field in self.fields:
if fname == name:
return field
raise ValueError("No field called %s on model %s" % (name, self.name))
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(self.fields, other.fields)) and
(self.options == other.options) and
(self.bases == other.bases) and
(self.managers == other.managers)
)
|
4f3f85e92ec82eb7fad01f285ca7f52f4954b7fdaa7739c2ea5ae99215cc3e49 | 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):
self.connection = connection
self.disk_migrations = None
self.applied_migrations = None
self.ignore_no_migrations = ignore_no_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 ImportError as e:
# I hate doing this, but I don't want to squash other import errors.
# Might be better to try a directory check directly.
if ((explicit and self.ignore_no_migrations) or (
not explicit and "No module named" in str(e) and MIGRATIONS_MODULE_NAME in str(e))):
self.unmigrated_apps.add(app_config.label)
continue
raise
else:
# Empty directories are namespaces.
# getattr() needed on PY36 and older (replace w/attribute access).
if getattr(module, '__file__', None) is None:
self.unmigrated_apps.add(app_config.label)
continue
# Module is not a package (e.g. migrations.py).
if not hasattr(module, '__path__'):
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("There no migrations for '%s' with the prefix '%s'" % (app_label, 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.
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]
# Ensure 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 exc
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: 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=list(self.unmigrated_apps))
|
e90b1243a8ce48f06331db8f584b0bce26e2e3f0abdd177cc18ed37425a23515 |
import os
import re
from importlib import import_module
from django import get_version
from django.apps import apps
# SettingsReference imported for backwards compatibility in Django 2.2.
from django.conf import SettingsReference # NOQA
from django.db import migrations
from django.db.migrations.loader import MigrationLoader
from django.db.migrations.serializer import Serializer, serializer_factory
from django.utils.inspect import get_func_args
from django.utils.module_loading import module_dir
from django.utils.timezone import now
class OperationWriter:
def __init__(self, operation, indentation=2):
self.operation = operation
self.buff = []
self.indentation = indentation
def serialize(self):
def _write(_arg_name, _arg_value):
if (_arg_name in self.operation.serialization_expand_args and
isinstance(_arg_value, (list, tuple, dict))):
if isinstance(_arg_value, dict):
self.feed('%s={' % _arg_name)
self.indent()
for key, value in _arg_value.items():
key_string, key_imports = MigrationWriter.serialize(key)
arg_string, arg_imports = MigrationWriter.serialize(value)
args = arg_string.splitlines()
if len(args) > 1:
self.feed('%s: %s' % (key_string, args[0]))
for arg in args[1:-1]:
self.feed(arg)
self.feed('%s,' % args[-1])
else:
self.feed('%s: %s,' % (key_string, arg_string))
imports.update(key_imports)
imports.update(arg_imports)
self.unindent()
self.feed('},')
else:
self.feed('%s=[' % _arg_name)
self.indent()
for item in _arg_value:
arg_string, arg_imports = MigrationWriter.serialize(item)
args = arg_string.splitlines()
if len(args) > 1:
for arg in args[:-1]:
self.feed(arg)
self.feed('%s,' % args[-1])
else:
self.feed('%s,' % arg_string)
imports.update(arg_imports)
self.unindent()
self.feed('],')
else:
arg_string, arg_imports = MigrationWriter.serialize(_arg_value)
args = arg_string.splitlines()
if len(args) > 1:
self.feed('%s=%s' % (_arg_name, args[0]))
for arg in args[1:-1]:
self.feed(arg)
self.feed('%s,' % args[-1])
else:
self.feed('%s=%s,' % (_arg_name, arg_string))
imports.update(arg_imports)
imports = set()
name, args, kwargs = self.operation.deconstruct()
operation_args = get_func_args(self.operation.__init__)
# See if this operation is in django.db.migrations. If it is,
# We can just use the fact we already have that imported,
# otherwise, we need to add an import for the operation class.
if getattr(migrations, name, None) == self.operation.__class__:
self.feed('migrations.%s(' % name)
else:
imports.add('import %s' % (self.operation.__class__.__module__))
self.feed('%s.%s(' % (self.operation.__class__.__module__, name))
self.indent()
for i, arg in enumerate(args):
arg_value = arg
arg_name = operation_args[i]
_write(arg_name, arg_value)
i = len(args)
# Only iterate over remaining arguments
for arg_name in operation_args[i:]:
if arg_name in kwargs: # Don't sort to maintain signature order
arg_value = kwargs[arg_name]
_write(arg_name, arg_value)
self.unindent()
self.feed('),')
return self.render(), imports
def indent(self):
self.indentation += 1
def unindent(self):
self.indentation -= 1
def feed(self, line):
self.buff.append(' ' * (self.indentation * 4) + line)
def render(self):
return '\n'.join(self.buff)
class MigrationWriter:
"""
Take a Migration instance and is able to produce the contents
of the migration file from it.
"""
def __init__(self, migration, include_header=True):
self.migration = migration
self.include_header = include_header
self.needs_manual_porting = False
def as_string(self):
"""Return a string of the file contents."""
items = {
"replaces_str": "",
"initial_str": "",
}
imports = set()
# Deconstruct operations
operations = []
for operation in self.migration.operations:
operation_string, operation_imports = OperationWriter(operation).serialize()
imports.update(operation_imports)
operations.append(operation_string)
items["operations"] = "\n".join(operations) + "\n" if operations else ""
# Format dependencies and write out swappable dependencies right
dependencies = []
for dependency in self.migration.dependencies:
if dependency[0] == "__setting__":
dependencies.append(" migrations.swappable_dependency(settings.%s)," % dependency[1])
imports.add("from django.conf import settings")
else:
dependencies.append(" %s," % self.serialize(dependency)[0])
items["dependencies"] = "\n".join(dependencies) + "\n" if dependencies else ""
# Format imports nicely, swapping imports of functions from migration files
# for comments
migration_imports = set()
for line in list(imports):
if re.match(r"^import (.*)\.\d+[^\s]*$", line):
migration_imports.add(line.split("import")[1].strip())
imports.remove(line)
self.needs_manual_porting = True
# django.db.migrations is always used, but models import may not be.
# If models import exists, merge it with migrations import.
if "from django.db import models" in imports:
imports.discard("from django.db import models")
imports.add("from django.db import migrations, models")
else:
imports.add("from django.db import migrations")
# Sort imports by the package / module to be imported (the part after
# "from" in "from ... import ..." or after "import" in "import ...").
sorted_imports = sorted(imports, key=lambda i: i.split()[1])
items["imports"] = "\n".join(sorted_imports) + "\n" if imports else ""
if migration_imports:
items["imports"] += (
"\n\n# Functions from the following migrations need manual "
"copying.\n# Move them and any dependencies into this file, "
"then update the\n# RunPython operations to refer to the local "
"versions:\n# %s"
) % "\n# ".join(sorted(migration_imports))
# If there's a replaces, make a string for it
if self.migration.replaces:
items['replaces_str'] = "\n replaces = %s\n" % self.serialize(self.migration.replaces)[0]
# Hinting that goes into comment
if self.include_header:
items['migration_header'] = MIGRATION_HEADER_TEMPLATE % {
'version': get_version(),
'timestamp': now().strftime("%Y-%m-%d %H:%M"),
}
else:
items['migration_header'] = ""
if self.migration.initial:
items['initial_str'] = "\n initial = True\n"
return MIGRATION_TEMPLATE % items
@property
def basedir(self):
migrations_package_name, _ = MigrationLoader.migrations_module(self.migration.app_label)
if migrations_package_name is None:
raise ValueError(
"Django can't create migrations for app '%s' because "
"migrations have been disabled via the MIGRATION_MODULES "
"setting." % self.migration.app_label
)
# See if we can import the migrations module directly
try:
migrations_module = import_module(migrations_package_name)
except ImportError:
pass
else:
try:
return module_dir(migrations_module)
except ValueError:
pass
# Alright, see if it's a direct submodule of the app
app_config = apps.get_app_config(self.migration.app_label)
maybe_app_name, _, migrations_package_basename = migrations_package_name.rpartition(".")
if app_config.name == maybe_app_name:
return os.path.join(app_config.path, migrations_package_basename)
# In case of using MIGRATION_MODULES setting and the custom package
# doesn't exist, create one, starting from an existing package
existing_dirs, missing_dirs = migrations_package_name.split("."), []
while existing_dirs:
missing_dirs.insert(0, existing_dirs.pop(-1))
try:
base_module = import_module(".".join(existing_dirs))
except (ImportError, ValueError):
continue
else:
try:
base_dir = module_dir(base_module)
except ValueError:
continue
else:
break
else:
raise ValueError(
"Could not locate an appropriate location to create "
"migrations package %s. Make sure the toplevel "
"package exists and can be imported." %
migrations_package_name)
final_dir = os.path.join(base_dir, *missing_dirs)
os.makedirs(final_dir, exist_ok=True)
for missing_dir in missing_dirs:
base_dir = os.path.join(base_dir, missing_dir)
with open(os.path.join(base_dir, "__init__.py"), "w"):
pass
return final_dir
@property
def filename(self):
return "%s.py" % self.migration.name
@property
def path(self):
return os.path.join(self.basedir, self.filename)
@classmethod
def serialize(cls, value):
return serializer_factory(value).serialize()
@classmethod
def register_serializer(cls, type_, serializer):
Serializer.register(type_, serializer)
@classmethod
def unregister_serializer(cls, type_):
Serializer.unregister(type_)
MIGRATION_HEADER_TEMPLATE = """\
# Generated by Django %(version)s on %(timestamp)s
"""
MIGRATION_TEMPLATE = """\
%(migration_header)s%(imports)s
class Migration(migrations.Migration):
%(replaces_str)s%(initial_str)s
dependencies = [
%(dependencies)s\
]
operations = [
%(operations)s\
]
"""
|
f708dedef6a8711e2330a4cb2d54705c408c0fb15949d25b87ea38fbe48abc0d | import datetime
import importlib
import os
import sys
from django.apps import apps
from django.db.models.fields import NOT_PROVIDED
from django.utils import timezone
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:
# getattr() needed on PY36 and older (replace with attribute access).
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):
"""Do you really want to merge these migrations?"""
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
class InteractiveMigrationQuestioner(MigrationQuestioner):
def _boolean_input(self, question, default=None):
result = input("%s " % question)
if not result and default is not None:
return default
while not result or result[0].lower() not in "yn":
result = input("Please answer yes or no: ")
return result[0].lower() == "y"
def _choice_input(self, question, choices):
print(question)
for i, choice in enumerate(choices):
print(" %s) %s" % (i + 1, choice))
result = input("Select an option: ")
while True:
try:
value = int(result)
except ValueError:
pass
else:
if 0 < value <= len(choices):
return value
result = input("Please select a valid option: ")
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.
"""
print("Please enter the default value now, as valid Python")
if default:
print(
"You can accept the default '{}' by pressing 'Enter' or you "
"can provide another value.".format(default)
)
print("The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now")
print("Type 'exit' to exit this prompt")
while True:
if default:
prompt = "[default: {}] >>> ".format(default)
else:
prompt = ">>> "
code = input(prompt)
if not code and default:
code = default
if not code:
print("Please enter some code, or 'exit' (with no quotes) to exit.")
elif code == "exit":
sys.exit(1)
else:
try:
return eval(code, {}, {'datetime': datetime, 'timezone': timezone})
except (SyntaxError, NameError) as e:
print("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(
"You are trying to add a non-nullable field '%s' to %s without a default; "
"we can't do that (the database needs something to populate existing rows).\n"
"Please select a fix:" % (field_name, model_name),
[
("Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"),
"Quit, and let me add a default 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(
"You are trying to change the nullable field '%s' on %s to non-nullable "
"without a default; we can't do that (the database needs something to "
"populate existing rows).\n"
"Please select a fix:" % (field_name, model_name),
[
("Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"),
("Ignore for now, and let me handle existing rows with NULL myself "
"(e.g. because you added a RunPython or RunSQL operation to handle "
"NULL values in a previous data migration)"),
"Quit, and let me add a default 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 = "Did you rename %s.%s 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 = "Did you rename the %s.%s model 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" +
"Do you want to merge these migration branches? [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(
"You are trying to add the field '{}' with 'auto_now_add=True' "
"to {} without a default; the database needs something to "
"populate existing rows.\n".format(field_name, model_name),
[
"Provide a one-off default now (will be set on all "
"existing rows)",
"Quit, and let me add a default in models.py",
]
)
if choice == 2:
sys.exit(3)
else:
return self._ask_default(default='timezone.now')
return None
class NonInteractiveMigrationQuestioner(MigrationQuestioner):
def ask_not_null_addition(self, field_name, model_name):
# We can't ask the user, so act like the user aborted.
sys.exit(3)
def ask_not_null_alteration(self, field_name, model_name):
# We can't ask the user, so set as not provided.
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.
sys.exit(3)
|
aa1a3776a91b9bc43269179b19050141616fd5343eef4012f1a5ad3a6c3722eb | from functools import total_ordering
from django.db.migrations.state import ProjectState
from .exceptions import CircularDependencyError, NodeNotFoundError
@total_ordering
class Node:
"""
A single node in the migration graph. Contains direct links to adjacent
nodes in either direction.
"""
def __init__(self, key):
self.key = key
self.children = set()
self.parents = set()
def __eq__(self, other):
return self.key == other
def __lt__(self, other):
return self.key < other
def __hash__(self):
return hash(self.key)
def __getitem__(self, item):
return self.key[item]
def __str__(self):
return str(self.key)
def __repr__(self):
return '<%s: (%r, %r)>' % (self.__class__.__name__, self.key[0], self.key[1])
def add_child(self, child):
self.children.add(child)
def add_parent(self, parent):
self.parents.add(parent)
class DummyNode(Node):
"""
A node that doesn't correspond to a migration file on disk.
(A squashed migration that was removed, for example.)
After the migration graph is processed, all dummy nodes should be removed.
If there are any left, a nonexistent dependency error is raised.
"""
def __init__(self, key, origin, error_message):
super().__init__(key)
self.origin = origin
self.error_message = error_message
def raise_error(self):
raise NodeNotFoundError(self.error_message, self.key, origin=self.origin)
class MigrationGraph:
"""
Represent the digraph of all migrations in a project.
Each migration is a node, and each dependency is an edge. There are
no implicit dependencies between numbered migrations - the numbering is
merely a convention to aid file listing. Every new numbered migration
has a declared dependency to the previous number, meaning that VCS
branch merges can be detected and resolved.
Migrations files can be marked as replacing another set of migrations -
this is to support the "squash" feature. The graph handler isn't responsible
for these; instead, the code to load them in here should examine the
migration files and if the replaced migrations are all either unapplied
or not present, it should ignore the replaced ones, load in just the
replacing migration, and repoint any dependencies that pointed to the
replaced migrations to point to the replacing one.
A node should be a tuple: (app_path, migration_name). The tree special-cases
things within an app - namely, root nodes and leaf nodes ignore dependencies
to other apps.
"""
def __init__(self):
self.node_map = {}
self.nodes = {}
def add_node(self, key, migration):
assert key not in self.node_map
node = Node(key)
self.node_map[key] = node
self.nodes[key] = migration
def add_dummy_node(self, key, origin, error_message):
node = DummyNode(key, origin, error_message)
self.node_map[key] = node
self.nodes[key] = None
def add_dependency(self, migration, child, parent, skip_validation=False):
"""
This may create dummy nodes if they don't yet exist. If
`skip_validation=True`, validate_consistency() should be called
afterwards.
"""
if child not in self.nodes:
error_message = (
"Migration %s dependencies reference nonexistent"
" child node %r" % (migration, child)
)
self.add_dummy_node(child, migration, error_message)
if parent not in self.nodes:
error_message = (
"Migration %s dependencies reference nonexistent"
" parent node %r" % (migration, parent)
)
self.add_dummy_node(parent, migration, error_message)
self.node_map[child].add_parent(self.node_map[parent])
self.node_map[parent].add_child(self.node_map[child])
if not skip_validation:
self.validate_consistency()
def remove_replaced_nodes(self, replacement, replaced):
"""
Remove each of the `replaced` nodes (when they exist). Any
dependencies that were referencing them are changed to reference the
`replacement` node instead.
"""
# Cast list of replaced keys to set to speed up lookup later.
replaced = set(replaced)
try:
replacement_node = self.node_map[replacement]
except KeyError as err:
raise NodeNotFoundError(
"Unable to find replacement node %r. It was either never added"
" to the migration graph, or has been removed." % (replacement,),
replacement
) from err
for replaced_key in replaced:
self.nodes.pop(replaced_key, None)
replaced_node = self.node_map.pop(replaced_key, None)
if replaced_node:
for child in replaced_node.children:
child.parents.remove(replaced_node)
# We don't want to create dependencies between the replaced
# node and the replacement node as this would lead to
# self-referencing on the replacement node at a later iteration.
if child.key not in replaced:
replacement_node.add_child(child)
child.add_parent(replacement_node)
for parent in replaced_node.parents:
parent.children.remove(replaced_node)
# Again, to avoid self-referencing.
if parent.key not in replaced:
replacement_node.add_parent(parent)
parent.add_child(replacement_node)
def remove_replacement_node(self, replacement, replaced):
"""
The inverse operation to `remove_replaced_nodes`. Almost. Remove the
replacement node `replacement` and remap its child nodes to `replaced`
- the list of nodes it would have replaced. Don't remap its parent
nodes as they are expected to be correct already.
"""
self.nodes.pop(replacement, None)
try:
replacement_node = self.node_map.pop(replacement)
except KeyError as err:
raise NodeNotFoundError(
"Unable to remove replacement node %r. It was either never added"
" to the migration graph, or has been removed already." % (replacement,),
replacement
) from err
replaced_nodes = set()
replaced_nodes_parents = set()
for key in replaced:
replaced_node = self.node_map.get(key)
if replaced_node:
replaced_nodes.add(replaced_node)
replaced_nodes_parents |= replaced_node.parents
# We're only interested in the latest replaced node, so filter out
# replaced nodes that are parents of other replaced nodes.
replaced_nodes -= replaced_nodes_parents
for child in replacement_node.children:
child.parents.remove(replacement_node)
for replaced_node in replaced_nodes:
replaced_node.add_child(child)
child.add_parent(replaced_node)
for parent in replacement_node.parents:
parent.children.remove(replacement_node)
# NOTE: There is no need to remap parent dependencies as we can
# assume the replaced nodes already have the correct ancestry.
def validate_consistency(self):
"""Ensure there are no dummy nodes remaining in the graph."""
[n.raise_error() for n in self.node_map.values() if isinstance(n, DummyNode)]
def forwards_plan(self, target):
"""
Given a node, return a list of which previous nodes (dependencies) must
be applied, ending with the node itself. This is the list you would
follow if applying the migrations to a database.
"""
if target not in self.nodes:
raise NodeNotFoundError("Node %r not a valid node" % (target,), target)
return self.iterative_dfs(self.node_map[target])
def backwards_plan(self, target):
"""
Given a node, return a list of which dependent nodes (dependencies)
must be unapplied, ending with the node itself. This is the list you
would follow if removing the migrations from a database.
"""
if target not in self.nodes:
raise NodeNotFoundError("Node %r not a valid node" % (target,), target)
return self.iterative_dfs(self.node_map[target], forwards=False)
def iterative_dfs(self, start, forwards=True):
"""Iterative depth-first search for finding dependencies."""
visited = []
visited_set = set()
stack = [(start, False)]
while stack:
node, processed = stack.pop()
if node in visited_set:
pass
elif processed:
visited_set.add(node)
visited.append(node.key)
else:
stack.append((node, True))
stack += [(n, False) for n in sorted(node.parents if forwards else node.children)]
return visited
def root_nodes(self, app=None):
"""
Return all root nodes - that is, nodes with no dependencies inside
their app. These are the starting point for an app.
"""
roots = set()
for node in self.nodes:
if all(key[0] != node[0] for key in self.node_map[node].parents) and (not app or app == node[0]):
roots.add(node)
return sorted(roots)
def leaf_nodes(self, app=None):
"""
Return all leaf nodes - that is, nodes with no dependents in their app.
These are the "most current" version of an app's schema.
Having more than one per app is technically an error, but one that
gets handled further up, in the interactive command - it's usually the
result of a VCS merge and needs some user input.
"""
leaves = set()
for node in self.nodes:
if all(key[0] != node[0] for key in self.node_map[node].children) and (not app or app == node[0]):
leaves.add(node)
return sorted(leaves)
def ensure_not_cyclic(self):
# Algo from GvR:
# https://neopythonic.blogspot.com/2009/01/detecting-cycles-in-directed-graph.html
todo = set(self.nodes)
while todo:
node = todo.pop()
stack = [node]
while stack:
top = stack[-1]
for child in self.node_map[top].children:
# Use child.key instead of child to speed up the frequent
# hashing.
node = child.key
if node in stack:
cycle = stack[stack.index(node):]
raise CircularDependencyError(", ".join("%s.%s" % n for n in cycle))
if node in todo:
stack.append(node)
todo.remove(node)
break
else:
node = stack.pop()
def __str__(self):
return 'Graph: %s nodes, %s edges' % self._nodes_and_edges()
def __repr__(self):
nodes, edges = self._nodes_and_edges()
return '<%s: nodes=%s, edges=%s>' % (self.__class__.__name__, nodes, edges)
def _nodes_and_edges(self):
return len(self.nodes), sum(len(node.parents) for node in self.node_map.values())
def _generate_plan(self, nodes, at_end):
plan = []
for node in nodes:
for migration in self.forwards_plan(node):
if migration not in plan and (at_end or migration not in nodes):
plan.append(migration)
return plan
def make_state(self, nodes=None, at_end=True, real_apps=None):
"""
Given a migration node or nodes, return a complete ProjectState for it.
If at_end is False, return the state before the migration has run.
If nodes is not provided, return the overall most current project state.
"""
if nodes is None:
nodes = list(self.leaf_nodes())
if not nodes:
return ProjectState()
if not isinstance(nodes[0], tuple):
nodes = [nodes]
plan = self._generate_plan(nodes, at_end)
project_state = ProjectState(real_apps=real_apps)
for node in plan:
project_state = self.nodes[node].mutate_state(project_state, preserve=False)
return project_state
def __contains__(self, node):
return node in self.nodes
|
d58eb8efa632df509d82e3e119fee89ca1d5328438af6dc3993117b2af415980 | 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, get_migration_name_timestamp,
)
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,
of course, the related fields change during renames).
"""
fields_def = []
for name, field in sorted(fields):
deconstruction = self.deep_deconstruct(field)
if field.remote_field and field.remote_field.model:
del deconstruction[2]['to']
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_apps = self.from_state.concrete_apps
self.new_apps = self.to_state.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 al, mn in self.from_state.models:
model = self.old_apps.get_model(al, mn)
if not model._meta.managed:
self.old_unmanaged_keys.add((al, mn))
elif al not in self.from_state.real_apps:
if model._meta.proxy:
self.old_proxy_keys.add((al, mn))
else:
self.old_model_keys.add((al, mn))
for al, mn in self.to_state.models:
model = self.new_apps.get_model(al, mn)
if not model._meta.managed:
self.new_unmanaged_keys.add((al, mn))
elif (
al not in self.from_state.real_apps or
(convert_apps and al in convert_apps)
):
if model._meta.proxy:
self.new_proxy_keys.add((al, mn))
else:
self.new_model_keys.add((al, mn))
# 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 operations
self.generate_renamed_fields()
self.generate_removed_fields()
self.generate_added_fields()
self.generate_altered_fields()
self.generate_altered_unique_together()
self.generate_altered_index_together()
self.generate_added_indexes()
self.generate_added_constraints()
self.generate_altered_db_table()
self.generate_altered_order_with_respect_to()
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, x)
for app_label, model_name in self.kept_model_keys
for x, y 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, x)
for app_label, model_name in self.kept_model_keys
for x, y 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:
old_field = self.old_apps.get_model(app_label, old_model_name)._meta.get_field(field_name)
if (hasattr(old_field, "remote_field") and getattr(old_field.remote_field, "through", None) and
not old_field.remote_field.through._meta.auto_created):
through_key = (
old_field.remote_field.through._meta.app_label,
old_field.remote_field.through._meta.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=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 = self.new_apps.get_model(item[0], item[1])
base_names = [base.__name__ for base in model.__bases__]
string_version = "%s.%s" % (item[0], item[1])
if (
model._meta.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):
model_opts = self.new_apps.get_model(app_label, model_name)._meta
dependencies = []
for field in model_opts.get_fields():
if field.is_relation:
dependencies.extend(self._get_dependencies_for_foreign_key(field))
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)
self.renamed_models_rel[renamed_models_rel_key] = '%s.%s' % (
model_state.app_label,
model_state.name,
)
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]
model_opts = self.new_apps.get_model(app_label, model_name)._meta
# Gather related fields
related_fields = {}
primary_key_rel = None
for field in model_opts.local_fields:
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
# through will be none on M2Ms on swapped-out models;
# we can treat lack of through as auto_created=True, though.
if (getattr(field.remote_field, "through", None) and
not field.remote_field.through._meta.auto_created):
related_fields[field.name] = field
for field in model_opts.local_many_to_many:
if field.remote_field.model:
related_fields[field.name] = field
if getattr(field.remote_field, "through", None) and not field.remote_field.through._meta.auto_created:
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 other end of the primary key if it's a relation
if primary_key_rel:
dependencies.append((
primary_key_rel._meta.app_label,
primary_key_rel._meta.object_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 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_opts.managed:
continue
# Generate operations for each related field
for name, field in sorted(related_fields.items()):
dependencies = self._get_dependencies_for_foreign_key(field)
# 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
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
)
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),
]
)
# Fix relationships if the model changed from a proxy model to a
# concrete model.
if (app_label, model_name) in self.old_proxy_keys:
for related_object in model_opts.related_objects:
self.add_operation(
related_object.related_model._meta.app_label,
operations.AlterField(
model_name=related_object.related_model._meta.object_name,
name=related_object.field.name,
field=related_object.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 of course for proxy
models it's safe to skip all the pointless field stuff and just 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]
model = self.old_apps.get_model(app_label, model_name)
# Gather related fields
related_fields = {}
for field in model._meta.local_fields:
if field.remote_field:
if field.remote_field.model:
related_fields[field.name] = field
# through will be none on M2Ms on swapped-out models;
# we can treat lack of through as auto_created=True, though.
if (getattr(field.remote_field, "through", None) and
not field.remote_field.through._meta.auto_created):
related_fields[field.name] = field
for field in model._meta.local_many_to_many:
if field.remote_field.model:
related_fields[field.name] = field
if getattr(field.remote_field, "through", None) and not field.remote_field.through._meta.auto_created:
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 = []
for related_object in model._meta.related_objects:
related_object_app_label = related_object.related_model._meta.app_label
object_name = related_object.related_model._meta.object_name
field_name = related_object.field.name
dependencies.append((related_object_app_label, object_name, field_name, False))
if not related_object.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]
field = self.new_apps.get_model(app_label, model_name)._meta.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_by_name(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):
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.new_apps.get_model(app_label, model_name)._meta.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(field))
# 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)
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's 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.old_apps.get_model(app_label, old_model_name)._meta.get_field(old_field_name)
new_field = self.new_apps.get_model(app_label, model_name)._meta.get_field(field_name)
# 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 = (
new_field.remote_field.model._meta.app_label,
new_field.remote_field.model._meta.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:
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
])
if hasattr(new_field, "remote_field") and getattr(new_field.remote_field, "through", None):
rename_key = (
new_field.remote_field.through._meta.app_label,
new_field.remote_field.through._meta.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 old_field_dec != new_field_dec:
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,
)
)
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,
)
)
def _get_dependencies_for_foreign_key(self, field):
# 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 = field.remote_field.model._meta.app_label
dep_object_name = field.remote_field.model._meta.object_name
dependencies = [(dep_app_label, dep_object_name, None, True)]
if getattr(field.remote_field, "through", None) and not field.remote_field.through._meta.auto_created:
dependencies.append((
field.remote_field.through._meta.app_label,
field.remote_field.through._meta.object_name,
None,
True,
))
return dependencies
def _generate_altered_foo_together(self, operation):
option_name = operation.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 = self.new_apps.get_model(app_label, model_name)._meta.get_field(field_name)
if field.remote_field and field.remote_field.model:
dependencies.extend(self._get_dependencies_for_foreign_key(field))
self.add_operation(
app_label,
operation(
name=model_name,
**{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)
if i == 0 and not app_leaf:
new_name = "0001_%s" % migration_name if migration_name else "0001_initial"
else:
new_name = "%04i_%s" % (
next_number,
migration_name or self.suggest_name(migration.operations)[:100],
)
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 suggest_name(cls, ops):
"""
Given a set of operations, suggest a name for the migration they might
represent. Names are not guaranteed to be unique, but put some effort
into the fallback name to avoid VCS conflicts if possible.
"""
if len(ops) == 1:
if isinstance(ops[0], operations.CreateModel):
return ops[0].name_lower
elif isinstance(ops[0], operations.DeleteModel):
return "delete_%s" % ops[0].name_lower
elif isinstance(ops[0], operations.AddField):
return "%s_%s" % (ops[0].model_name_lower, ops[0].name_lower)
elif isinstance(ops[0], operations.RemoveField):
return "remove_%s_%s" % (ops[0].model_name_lower, ops[0].name_lower)
elif ops:
if all(isinstance(o, operations.CreateModel) for o in ops):
return "_".join(sorted(o.name_lower for o in ops))
return "auto_%s" % get_migration_name_timestamp()
@classmethod
def parse_number(cls, name):
"""
Given a migration name, try to extract a number from the beginning of
it. If no number is found, return None.
"""
match = re.match(r'^\d+', name)
if match:
return int(match.group())
return None
|
56194386cb6b3daf36fe50bd9c58b253aefdb53179351cf62fc233de472830bc | from django.apps.registry import Apps
from django.db import models
from django.db.utils import DatabaseError
from django.utils.decorators import classproperty
from django.utils.timezone import now
from .exceptions import MigrationSchemaMissing
class MigrationRecorder:
"""
Deal with storing migration records in the database.
Because this table is actually itself used for dealing with model
creation, it's the one thing we can't do normally via migrations.
We manually handle table creation/schema updating (using schema backend)
and then have a floating model to do queries with.
If a migration is unapplied its row is removed from the table. Having
a row in the table always means a migration is applied.
"""
_migration_class = None
@classproperty
def Migration(cls):
"""
Lazy load to avoid AppRegistryNotReady if installed apps import
MigrationRecorder.
"""
if cls._migration_class is None:
class Migration(models.Model):
app = models.CharField(max_length=255)
name = models.CharField(max_length=255)
applied = models.DateTimeField(default=now)
class Meta:
apps = Apps()
app_label = 'migrations'
db_table = 'django_migrations'
def __str__(self):
return 'Migration %s for %s' % (self.name, self.app)
cls._migration_class = Migration
return cls._migration_class
def __init__(self, connection):
self.connection = connection
@property
def migration_qs(self):
return self.Migration.objects.using(self.connection.alias)
def has_table(self):
"""Return True if the django_migrations table exists."""
return self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor())
def ensure_schema(self):
"""Ensure the table exists and has the correct schema."""
# If the table's there, that's fine - we've never changed its schema
# in the codebase.
if self.has_table():
return
# Make the table
try:
with self.connection.schema_editor() as editor:
editor.create_model(self.Migration)
except DatabaseError as exc:
raise MigrationSchemaMissing("Unable to create the django_migrations table (%s)" % exc)
def applied_migrations(self):
"""
Return a dict mapping (app_name, migration_name) to Migration instances
for all applied migrations.
"""
if self.has_table():
return {(migration.app, migration.name): migration for migration in self.migration_qs}
else:
# If the django_migrations table doesn't exist, then no migrations
# are applied.
return {}
def record_applied(self, app, name):
"""Record that a migration was applied."""
self.ensure_schema()
self.migration_qs.create(app=app, name=name)
def record_unapplied(self, app, name):
"""Record that a migration was unapplied."""
self.ensure_schema()
self.migration_qs.filter(app=app, name=name).delete()
def flush(self):
"""Delete all migration records. Useful for testing migrations."""
self.migration_qs.all().delete()
|
fd298b8a91a82789da29c1583df3156f358357d76c30a229538473d8837be0c9 | class MigrationOptimizer:
"""
Power the optimization process, where you provide a list of Operations
and you are returned a list of equal or shorter length - operations
are merged into one if possible.
For example, a CreateModel and an AddField can be optimized into a
new CreateModel, and CreateModel and DeleteModel can be optimized into
nothing.
"""
def optimize(self, operations, app_label=None):
"""
Main optimization entry point. Pass in a list of Operation instances,
get out a new list of Operation instances.
Unfortunately, due to the scope of the optimization (two combinable
operations might be separated by several hundred others), this can't be
done as a peephole optimization with checks/output implemented on
the Operations themselves; instead, the optimizer looks at each
individual operation and scans forwards in the list to see if there
are any matches, stopping at boundaries - operations which can't
be optimized over (RunSQL, operations on the same field/model, etc.)
The inner loop is run until the starting list is the same as the result
list, and then the result is returned. This means that operation
optimization must be stable and always return an equal or shorter list.
The app_label argument is optional, but if you pass it you'll get more
efficient optimization.
"""
# Internal tracking variable for test assertions about # of loops
self._iterations = 0
while True:
result = self.optimize_inner(operations, app_label)
self._iterations += 1
if result == operations:
return result
operations = result
def optimize_inner(self, operations, app_label=None):
"""Inner optimization loop."""
new_operations = []
for i, operation in enumerate(operations):
right = True # Should we reduce on the right or on the left.
# Compare it to each operation after it
for j, other in enumerate(operations[i + 1:]):
in_between = operations[i + 1:i + j + 1]
result = operation.reduce(other, app_label)
if isinstance(result, list):
if right:
new_operations.extend(in_between)
new_operations.extend(result)
elif all(op.reduce(other, app_label) is True for op in in_between):
# Perform a left reduction if all of the in-between
# operations can optimize through other.
new_operations.extend(result)
new_operations.extend(in_between)
else:
# Otherwise keep trying.
new_operations.append(operation)
break
new_operations.extend(operations[i + j + 2:])
return new_operations
elif not result:
# Can't perform a right reduction.
right = False
else:
new_operations.append(operation)
return new_operations
|
1e1cc54c8886178bb259cbd3ab7022606a0a28f4f34e5fcad11be018ca0b675b | import builtins
import collections.abc
import datetime
import decimal
import enum
import functools
import math
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 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('<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__
v_string, v_imports = serializer_factory(self.value.value).serialize()
imports = {'import %s' % module, *v_imports}
return "%s.%s(%s)" % (module, enum_class.__name__, v_string), imports
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 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", []),
(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.__name__), {"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,
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,
}
@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())
)
|
6f7dde0a113c523ea70c8439a87264ff522f858a45aa9aa32f30d2192e36204a | """
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.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
def __init__(self, *expressions, distinct=False, filter=None, **extra):
if distinct and not self.allow_distinct:
raise TypeError("%s does not allow distinct." % self.__class__.__name__)
self.distinct = distinct
self.filter = filter
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))
return c
@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'
class Count(Aggregate):
function = 'COUNT'
name = 'Count'
output_field = IntegerField()
allow_distinct = True
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)
def convert_value(self, value, expression, connection):
return 0 if value is None else value
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'
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'}
|
4d34fcc9f30e857600cd366dde2f6cda69685a4a2df5ed956aae0d9282dd9fe9 | from django.db.backends.utils import names_digest, split_identifier
from django.db.models.query_utils import Q
from django.db.models.sql import Query
__all__ = ['Index']
class Index:
suffix = 'idx'
# The max length of the name of the index (restricted to 30 for
# cross-database compatibility with Oracle)
max_name_length = 30
def __init__(self, *, fields=(), name=None, db_tablespace=None, opclasses=(), condition=None):
if opclasses and not name:
raise ValueError('An index must be named to use opclasses.')
if not isinstance(condition, (type(None), Q)):
raise ValueError('Index.condition must be a Q instance.')
if condition and not name:
raise ValueError('An index must be named to use condition.')
if not isinstance(fields, (list, tuple)):
raise ValueError('Index.fields must be a list or tuple.')
if not isinstance(opclasses, (list, tuple)):
raise ValueError('Index.opclasses must be a list or tuple.')
if opclasses and len(fields) != len(opclasses):
raise ValueError('Index.fields and Index.opclasses must have the same number of elements.')
if not fields:
raise ValueError('At least one field is required to define an index.')
self.fields = list(fields)
# A list of 2-tuple with the field name and ordering ('' or 'DESC').
self.fields_orders = [
(field_name[1:], 'DESC') if field_name.startswith('-') else (field_name, '')
for field_name in self.fields
]
self.name = name or ''
if self.name:
errors = self.check_name()
if len(self.name) > self.max_name_length:
errors.append('Index names cannot be longer than %s characters.' % self.max_name_length)
if errors:
raise ValueError(errors)
self.db_tablespace = db_tablespace
self.opclasses = opclasses
self.condition = condition
def check_name(self):
errors = []
# Name can't start with an underscore on Oracle; prepend D if needed.
if self.name[0] == '_':
errors.append('Index names cannot start with an underscore (_).')
self.name = 'D%s' % self.name[1:]
# Name can't start with a number on Oracle; prepend D if needed.
elif self.name[0].isdigit():
errors.append('Index names cannot start with a number (0-9).')
self.name = 'D%s' % self.name[1:]
return errors
def _get_condition_sql(self, model, schema_editor):
if self.condition is None:
return None
query = Query(model=model)
query.add_q(self.condition)
compiler = query.get_compiler(connection=schema_editor.connection)
# Only the WhereNode is of interest for the partial index.
sql, params = query.where.as_sql(compiler=compiler, connection=schema_editor.connection)
# BaseDatabaseSchemaEditor does the same map on the params, but since
# it's handled outside of that class, the work is done here.
return sql % tuple(map(schema_editor.quote_value, params))
def create_sql(self, model, schema_editor, using=''):
fields = [model._meta.get_field(field_name) for field_name, _ in self.fields_orders]
col_suffixes = [order[1] for order in self.fields_orders]
condition = self._get_condition_sql(model, schema_editor)
return schema_editor._create_index_sql(
model, fields, name=self.name, using=using, db_tablespace=self.db_tablespace,
col_suffixes=col_suffixes, opclasses=self.opclasses, condition=condition,
)
def remove_sql(self, model, schema_editor):
return schema_editor._delete_index_sql(model, self.name)
def deconstruct(self):
path = '%s.%s' % (self.__class__.__module__, self.__class__.__name__)
path = path.replace('django.db.models.indexes', 'django.db.models')
kwargs = {'fields': self.fields, 'name': self.name}
if self.db_tablespace is not None:
kwargs['db_tablespace'] = self.db_tablespace
if self.opclasses:
kwargs['opclasses'] = self.opclasses
if self.condition:
kwargs['condition'] = self.condition
return (path, (), kwargs)
def clone(self):
"""Create a copy of this Index."""
_, _, kwargs = self.deconstruct()
return self.__class__(**kwargs)
def set_name_with_model(self, model):
"""
Generate a unique name for the index.
The name is divided into 3 parts - table name (12 chars), field name
(8 chars) and unique hash + suffix (10 chars). Each part is made to
fit its size by truncating the excess length.
"""
_, table_name = split_identifier(model._meta.db_table)
column_names = [model._meta.get_field(field_name).column for field_name, order in self.fields_orders]
column_names_with_order = [
(('-%s' if order else '%s') % column_name)
for column_name, (field_name, order) in zip(column_names, self.fields_orders)
]
# The length of the parts of the name is based on the default max
# length of 30 characters.
hash_data = [table_name] + column_names_with_order + [self.suffix]
self.name = '%s_%s_%s' % (
table_name[:11],
column_names[0][:7],
'%s_%s' % (names_digest(*hash_data, length=6), self.suffix),
)
assert len(self.name) <= self.max_name_length, (
'Index too long for multiple database support. Is self.suffix '
'longer than 3 characters?'
)
self.check_name()
def __repr__(self):
return "<%s: fields='%s'%s>" % (
self.__class__.__name__, ', '.join(self.fields),
'' if self.condition is None else ', condition=%s' % self.condition,
)
def __eq__(self, other):
return (self.__class__ == other.__class__) and (self.deconstruct() == other.deconstruct())
|
b624a91649bddfc3b60dfb77dea748d8a3a67d56671cfbc68486f024c4a71c1b | """
The main QuerySet implementation. This provides the public API for the ORM.
"""
import copy
import operator
import warnings
from collections import namedtuple
from functools import lru_cache
from itertools import chain
from django.conf import settings
from django.core import exceptions
from django.db import (
DJANGO_VERSION_PICKLE_KEY, IntegrityError, connections, router,
transaction,
)
from django.db.models import DateField, DateTimeField, sql
from django.db.models.constants import LOOKUP_SEP
from django.db.models.deletion import Collector
from django.db.models.expressions import Case, Expression, F, Value, When
from django.db.models.fields import AutoField
from django.db.models.functions import Cast, Trunc
from django.db.models.query_utils import FilteredRelation, InvalidQuery, Q
from django.db.models.sql.constants import CURSOR, GET_ITERATOR_CHUNK_SIZE
from django.db.utils import NotSupportedError
from django.utils import timezone
from django.utils.functional import cached_property, partition
from django.utils.version import get_version
# 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
# Pull into this namespace for backwards compatibility.
EmptyResultSet = sql.EmptyResultSet
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.
"""
@staticmethod
@lru_cache()
def create_namedtuple_class(*names):
# Cache namedtuple() with @lru_cache() since it's too slow to be
# called for every QuerySet evaluation.
return namedtuple('Row', names)
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 = self.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
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: get_version()}
def __setstate__(self, state):
msg = None
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
current_version = get_version()
if current_version != pickled_version:
msg = (
"Pickled queryset instance's Django version %s does not "
"match the current version %s." % (pickled_version, current_version)
)
else:
msg = "Pickled queryset instance's Django version is not specified."
if msg:
warnings.warn(msg, 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
assert ((not isinstance(k, slice) and (k >= 0)) or
(isinstance(k, slice) and (k.start is None or k.start >= 0) and
(k.stop is None or k.stop >= 0))), \
"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 __and__(self, 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._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):
yield from self._iterable_class(self, chunked_fetch=use_chunked_fetch, chunk_size=chunk_size)
def iterator(self, chunk_size=2000):
"""
An iterator over the results from applying this QuerySet to the
database.
"""
if 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)
if not query.annotations[alias].contains_aggregate:
raise TypeError("%s is not an aggregate expression" % alias)
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.
"""
clone = 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 _populate_pk_values(self, objs):
for obj in objs:
if obj.pk is None:
obj.pk = obj._meta.pk.get_pk_value_on_save(obj)
def bulk_create(self, objs, batch_size=None, ignore_conflicts=False):
"""
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.
assert batch_size is None or batch_size > 0
# 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
self._for_write = True
connection = connections[self.db]
fields = self.model._meta.concrete_fields
objs = list(objs)
self._populate_pk_values(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:
self._batched_insert(objs_with_pk, fields, batch_size, ignore_conflicts=ignore_conflicts)
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)]
ids = self._batched_insert(objs_without_pk, fields, batch_size, ignore_conflicts=ignore_conflicts)
if connection.features.can_return_rows_from_bulk_insert and not ignore_conflicts:
assert len(ids) == len(objs_without_pk)
for obj_without_pk, pk in zip(objs_without_pk, ids):
obj_without_pk.pk = pk
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
# 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.
max_batch_size = connections[self.db].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 = connections[self.db].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 isinstance(attr, 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))
with transaction.atomic(using=self.db, savepoint=False):
for pks, update_kwargs in updates:
self.filter(pk__in=pks).update(**update_kwargs)
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)
return self._create_object_from_params(kwargs, params)
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):
try:
obj = self.select_for_update().get(**kwargs)
except self.model.DoesNotExist:
params = self._extract_model_params(defaults, **kwargs)
# Lock the row so that a concurrent update is blocked until
# after update_or_create() has performed its save.
obj, created = self._create_object_from_params(kwargs, params, lock=True)
if created:
return obj, created
for k, v in defaults.items():
setattr(obj, k, v() if callable(v) else v)
obj.save(using=self.db)
return obj, False
def _create_object_from_params(self, lookup, params, lock=False):
"""
Try to create an object using passed params. Used by get_or_create()
and update_or_create().
"""
try:
with transaction.atomic(using=self.db):
params = {k: v() if callable(v) else v for k, v in params.items()}
obj = self.create(**params)
return obj, True
except IntegrityError as e:
try:
qs = self.select_for_update() if lock else self
return qs.get(**lookup), False
except self.model.DoesNotExist:
pass
raise e
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() and update_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."
)
assert self.query.can_filter(), \
"Cannot change a query once a slice has been taken."
obj = self._chain()
obj.query.set_limits(high=1)
obj.query.clear_ordering(force_empty=True)
obj.query.add_ordering(*order_by)
return obj.get()
def earliest(self, *fields):
return self._earliest(*fields)
def latest(self, *fields):
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.
"""
assert self.query.can_filter(), \
"Cannot use 'limit' or 'offset' with in_bulk"
if field_name != 'pk' and not self.model._meta.get_field(field_name).unique:
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."""
assert self.query.can_filter(), \
"Cannot use 'limit' or 'offset' with delete."
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_empty=True)
collector = Collector(using=del_query.db)
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.
"""
return sql.DeleteQuery(self.model).delete_qs(self, using)
_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.
"""
assert self.query.can_filter(), \
"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).
"""
assert self.query.can_filter(), \
"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 _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=None, 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'.
"""
assert kind in ('year', 'month', 'week', 'day'), \
"'kind' must be one of 'year', 'month', 'week', or 'day'."
assert order in ('ASC', 'DESC'), \
"'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')
def datetimes(self, field_name, kind, order='ASC', tzinfo=None):
"""
Return a list of datetime objects representing all available
datetimes for the given field_name, scoped to 'kind'.
"""
assert kind in ('year', 'month', 'week', 'day', 'hour', 'minute', 'second'), \
"'kind' must be one of 'year', 'month', 'week', 'day', 'hour', 'minute', or 'second'."
assert order in ('ASC', 'DESC'), \
"'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),
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.
"""
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.
"""
return self._filter_or_exclude(True, *args, **kwargs)
def _filter_or_exclude(self, negate, *args, **kwargs):
if args or kwargs:
assert self.query.can_filter(), \
"Cannot filter a query once a slice has been taken."
clone = self._chain()
if negate:
clone.query.add_q(~Q(*args, **kwargs))
else:
clone.query.add_q(Q(*args, **kwargs))
return clone
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(None, **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(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)]
return qs[0]._combinator_query('union', *qs[1:], all=all) if qs else self
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=()):
"""
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
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.
"""
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.
"""
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._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)
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."""
assert self.query.can_filter(), \
"Cannot reorder a query once a slice has been taken."
obj = self._chain()
obj.query.clear_ordering(force_empty=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.
"""
assert self.query.can_filter(), \
"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."""
assert self.query.can_filter(), \
"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 not self.query.can_filter():
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.
"""
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.
"""
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:
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, return_id=False, raw=False, using=None, ignore_conflicts=False):
"""
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, ignore_conflicts=ignore_conflicts)
query.insert_values(fields, objs, raw=raw)
return query.get_compiler(using=using).execute_sql(return_id)
_insert.alters_data = True
_insert.queryset_only = False
def _batched_insert(self, objs, fields, batch_size, ignore_conflicts=False):
"""
Helper method for bulk_create() to insert objs one batch at a time.
"""
if ignore_conflicts and not connections[self.db].features.supports_ignore_conflicts:
raise NotSupportedError('This database backend does not support ignoring conflicts.')
ops = connections[self.db].ops
batch_size = (batch_size or max(ops.bulk_batch_size(fields, objs), 1))
inserted_ids = []
bulk_return = connections[self.db].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 not ignore_conflicts:
inserted_id = self._insert(
item, fields=fields, using=self.db, return_id=True,
ignore_conflicts=ignore_conflicts,
)
if isinstance(inserted_id, list):
inserted_ids.extend(inserted_id)
else:
inserted_ids.append(inserted_id)
else:
self._insert(item, fields=fields, using=self.db, ignore_conflicts=ignore_conflicts)
return inserted_ids
def _chain(self, **kwargs):
"""
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
obj.__dict__.update(kwargs)
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),
)
)
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=None,
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 or ()
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
compiler = connections[db].ops.compiler('SQLCompiler')(
self.query, connections[db], 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 InvalidQuery('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 not issubclass(queryset._iterable_class, ModelIterable):
raise ValueError('Prefetch querysets cannot use values().')
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:
# Prevent the QuerySet from being evaluated
obj_dict['queryset'] = self.queryset._chain(
_result_cache=[],
_prefetch_done=True,
)
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):
return isinstance(other, Prefetch) and 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)
if prefetcher is not None and not is_fetched:
obj_list, additional_lookups = prefetch_one_level(obj_list, 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 boolean that is True if the attribute has already been fetched)
"""
prefetcher = None
is_fetched = False
# 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
if rel_obj_descriptor.is_cached(instance):
is_fetched = True
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):
is_fetched = to_attr in instance.__dict__
else:
is_fetched = hasattr(instance, to_attr)
else:
is_fetched = through_attr in instance._prefetched_objects_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
|
e1708f0f415f882b5f10140131a1832e5c617d3820e4a0a102b2c453e036944d | from django.core.exceptions import ObjectDoesNotExist
from django.db.models import signals
from django.db.models.aggregates import * # NOQA
from django.db.models.aggregates import __all__ as aggregates_all
from django.db.models.constraints import * # NOQA
from django.db.models.constraints import __all__ as constraints_all
from django.db.models.deletion import (
CASCADE, DO_NOTHING, PROTECT, SET, SET_DEFAULT, SET_NULL, ProtectedError,
)
from django.db.models.expressions import (
Case, Exists, Expression, ExpressionList, ExpressionWrapper, F, Func,
OuterRef, RowRange, Subquery, Value, ValueRange, When, Window, WindowFrame,
)
from django.db.models.fields import * # NOQA
from django.db.models.fields import __all__ as fields_all
from django.db.models.fields.files import FileField, ImageField
from django.db.models.fields.proxy import OrderWrt
from django.db.models.indexes import * # NOQA
from django.db.models.indexes import __all__ as indexes_all
from django.db.models.lookups import Lookup, Transform
from django.db.models.manager import Manager
from django.db.models.query import (
Prefetch, Q, QuerySet, prefetch_related_objects,
)
from django.db.models.query_utils import FilteredRelation
# Imports that would create circular imports if sorted
from django.db.models.base import DEFERRED, Model # isort:skip
from django.db.models.fields.related import ( # isort:skip
ForeignKey, ForeignObject, OneToOneField, ManyToManyField,
ManyToOneRel, ManyToManyRel, OneToOneRel,
)
__all__ = aggregates_all + constraints_all + fields_all + indexes_all
__all__ += [
'ObjectDoesNotExist', 'signals',
'CASCADE', 'DO_NOTHING', 'PROTECT', 'SET', 'SET_DEFAULT', 'SET_NULL',
'ProtectedError',
'Case', 'Exists', 'Expression', 'ExpressionList', 'ExpressionWrapper', 'F',
'Func', 'OuterRef', 'RowRange', 'Subquery', 'Value', 'ValueRange', 'When',
'Window', 'WindowFrame',
'FileField', 'ImageField', 'OrderWrt', 'Lookup', 'Transform', 'Manager',
'Prefetch', 'Q', 'QuerySet', 'prefetch_related_objects', 'DEFERRED', 'Model',
'FilteredRelation',
'ForeignKey', 'ForeignObject', 'OneToOneField', 'ManyToManyField',
'ManyToOneRel', 'ManyToManyRel', 'OneToOneRel',
]
|
92393b1732e038909c96e1ed5cf3a81da16b15ceb21fb0eb418e520ff03ac038 | import copy
import inspect
from bisect import bisect
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 Manager
from django.db.models.fields import AutoField
from django.db.models.fields.proxy import OrderWrt
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.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)
@property
def installed(self):
return self.app_config is not None
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)
# 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 _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)
if not field.remote_field.parent_link:
raise ImproperlyConfigured(
'Add parent_link=True to %s.' % field,
)
else:
auto = AutoField(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:
self.local_many_to_many.insert(bisect(self.local_many_to_many, field), field)
else:
self.local_fields.insert(bisect(self.local_fields, field), 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 "%s.%s" % (self.app_label, self.model_name)
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.get_reverse_path_info())
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):
related_objects_graph[f.remote_field.model._meta.concrete_model._meta].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]
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 _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)
|
c93c4f3a47cdae918adc71e9ee6744abeb9b1c16ffdd4b2c948d98d1b54ad43e | import copy
import inspect
import warnings
from functools import partialmethod
from itertools import chain
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.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.manager import Manager
from django.db.models.options import Options
from django.db.models.query import 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.text import capfirst, get_text_list
from django.utils.translation import gettext_lazy as _
from django.utils.version import get_version
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 list(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):
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 ModelStateFieldsCacheDescriptor:
def __get__(self, instance, cls=None):
if instance is None:
return self
res = instance.fields_cache = {}
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 = ModelStateFieldsCacheDescriptor()
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
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)
kwargs.pop(field.name, None)
# 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:
# Object instance was passed in. Special case: You can
# pass in "None" for related objects if it's allowed.
if rel_obj is None and field.null:
val = None
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
for prop in tuple(kwargs):
try:
# Any remaining kwargs must correspond to properties or
# virtual fields.
if prop in property_names or opts.get_field(prop):
if kwargs[prop] is not _DEFERRED:
_setattr(self, prop, kwargs[prop])
del kwargs[prop]
except (AttributeError, FieldDoesNotExist):
pass
for kwarg in kwargs:
raise TypeError("%s() got an unexpected keyword argument '%s'" % (cls.__name__, kwarg))
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 False
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] = get_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."""
return self.__dict__
def __setstate__(self, state):
msg = None
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
current_version = get_version()
if current_version != pickled_version:
msg = (
"Pickled model instance's Django version %s does not match "
"the current version %s." % (pickled_version, current_version)
)
else:
msg = "Pickled model instance's Django version is not specified."
if msg:
warnings.warn(msg, RuntimeWarning, stacklevel=2)
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):
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.
"""
# 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 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(
"save() prohibited to prevent data loss due to "
"unsaved related object '%s'." % field.name
)
elif getattr(self, field.attname) is None:
# 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)
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.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 or are m2m 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
# 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)
order_value = cls._base_manager.using(using).filter(**filter_args).count()
self._order = order_value
fields = meta.local_concrete_fields
if not pk_set:
fields = [f for f in fields if f is not meta.auto_field]
update_pk = meta.auto_field and not pk_set
result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
if update_pk:
setattr(self, meta.pk.attname, result)
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, update_pk, raw):
"""
Do an INSERT. If update_pk is defined then this method should return
the new pk for the model.
"""
return manager._insert([self], fields=fields, return_id=update_pk,
using=using, raw=raw)
def delete(self, using=None, keep_parents=False):
using = using or router.db_for_write(self.__class__, instance=self)
assert self.pk is not None, (
"%s object can't be deleted because its %s attribute is set to None." %
(self._meta.object_name, self._meta.pk.attname)
)
collector = Collector(using=using)
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)
# force_str() to coerce lazy strings.
return force_str(dict(field.flatchoices).get(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(**{'%s__%s' % (field.name, op): param})
q = q | Q(**{field.name: param, 'pk__%s' % op: self.pk})
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.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.constraints:
constraints.append((parent_class, parent_class._meta.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 (isinstance(constraint, UniqueConstraint) and
# Partial unique constraints can't be validated.
constraint.condition is None and
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:
errors += [
*cls._check_fields(**kwargs),
*cls._check_m2m_through_same_relationship(),
*cls._check_long_column_names(),
]
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(),
*cls._check_ordering(),
*cls._check_constraints(),
]
return errors
@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):
"""Check the fields of indexes."""
fields = [field for index in cls._meta.indexes for field, _ in index.fields_orders]
return cls._check_local_fields(fields, 'indexes')
@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:
fld = _cls._meta.get_field(part)
if fld.is_relation:
_cls = fld.get_path_info()[-1].to_opts.model
except (FieldDoesNotExist, AttributeError):
if fld is None or fld.get_transform(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):
"""
Check that any auto-generated column names are shorter than the limits
for each database in which the model will be created.
"""
errors = []
allowed_len = None
db_alias = None
# Find the minimum max allowed length among all specified db_aliases.
for db in settings.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 _check_constraints(cls):
errors = []
for db in settings.DATABASES:
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
if connection.features.supports_table_check_constraints:
continue
if 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',
)
)
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
|
bd70fc8befe92fb76dcda0d6e351431558ee2366e80574048eb734bc0c28c87f | """
Various data structures used in query construction.
Factored out from django.db.models.query to avoid making the main module very
large and/or so that they can be used by other modules without getting into
circular import difficulties.
"""
import copy
import functools
import inspect
from collections import namedtuple
from django.db.models.constants import LOOKUP_SEP
from django.utils import tree
# PathInfo is used when converting lookups (fk__somecol). The contents
# describe the relation in Model terms (model Options and Fields for both
# sides of the relation. The join_field is the field backing the relation.
PathInfo = namedtuple('PathInfo', 'from_opts to_opts target_fields join_field m2m direct filtered_relation')
class InvalidQuery(Exception):
"""The query passed to raw() isn't a safe query to use with raw()."""
pass
def subclasses(cls):
yield cls
for subclass in cls.__subclasses__():
yield from subclasses(subclass)
class QueryWrapper:
"""
A type that indicates the contents are an SQL fragment and the associate
parameters. Can be used to pass opaque data to a where-clause, for example.
"""
contains_aggregate = False
def __init__(self, sql, params):
self.data = sql, list(params)
def as_sql(self, compiler=None, connection=None):
return self.data
class Q(tree.Node):
"""
Encapsulate filters as objects that can then be combined logically (using
`&` and `|`).
"""
# Connection types
AND = 'AND'
OR = 'OR'
default = AND
conditional = True
def __init__(self, *args, _connector=None, _negated=False, **kwargs):
super().__init__(children=[*args, *sorted(kwargs.items())], connector=_connector, negated=_negated)
def _combine(self, other, conn):
if not isinstance(other, Q):
raise TypeError(other)
# If the other Q() is empty, ignore it and just use `self`.
if not other:
return copy.deepcopy(self)
# Or if this Q is empty, ignore it and just use `other`.
elif not self:
return copy.deepcopy(other)
obj = type(self)()
obj.connector = conn
obj.add(self, conn)
obj.add(other, conn)
return obj
def __or__(self, other):
return self._combine(other, self.OR)
def __and__(self, other):
return self._combine(other, self.AND)
def __invert__(self):
obj = type(self)()
obj.add(self, self.AND)
obj.negate()
return obj
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
# We must promote any new joins to left outer joins so that when Q is
# used as an expression, rows aren't filtered due to joins.
clause, joins = query._add_q(self, reuse, allow_joins=allow_joins, split_subq=False)
query.promote_joins(joins)
return clause
def deconstruct(self):
path = '%s.%s' % (self.__class__.__module__, self.__class__.__name__)
if path.startswith('django.db.models.query_utils'):
path = path.replace('django.db.models.query_utils', 'django.db.models')
args, kwargs = (), {}
if len(self.children) == 1 and not isinstance(self.children[0], Q):
child = self.children[0]
kwargs = {child[0]: child[1]}
else:
args = tuple(self.children)
if self.connector != self.default:
kwargs = {'_connector': self.connector}
if self.negated:
kwargs['_negated'] = True
return path, args, kwargs
class DeferredAttribute:
"""
A wrapper for a deferred-loading field. When the value is read from this
object the first time, the query is executed.
"""
def __init__(self, field_name):
self.field_name = field_name
def __get__(self, instance, cls=None):
"""
Retrieve and caches the value from the datastore on the first lookup.
Return the cached value.
"""
if instance is None:
return self
data = instance.__dict__
if data.get(self.field_name, self) is self:
# Let's see if the field is part of the parent chain. If so we
# might be able to reuse the already loaded value. Refs #18343.
val = self._check_parent_chain(instance, self.field_name)
if val is None:
instance.refresh_from_db(fields=[self.field_name])
val = getattr(instance, self.field_name)
data[self.field_name] = val
return data[self.field_name]
def _check_parent_chain(self, instance, name):
"""
Check if the field value can be fetched from a parent field already
loaded in the instance. This can be done if the to-be fetched
field is a primary key field.
"""
opts = instance._meta
f = opts.get_field(name)
link_field = opts.get_ancestor_link(f.model)
if f.primary_key and f != link_field:
return getattr(instance, link_field.attname)
return None
class RegisterLookupMixin:
@classmethod
def _get_lookup(cls, lookup_name):
return cls.get_lookups().get(lookup_name, None)
@classmethod
@functools.lru_cache(maxsize=None)
def get_lookups(cls):
class_lookups = [parent.__dict__.get('class_lookups', {}) for parent in inspect.getmro(cls)]
return cls.merge_dicts(class_lookups)
def get_lookup(self, lookup_name):
from django.db.models.lookups import Lookup
found = self._get_lookup(lookup_name)
if found is None and hasattr(self, 'output_field'):
return self.output_field.get_lookup(lookup_name)
if found is not None and not issubclass(found, Lookup):
return None
return found
def get_transform(self, lookup_name):
from django.db.models.lookups import Transform
found = self._get_lookup(lookup_name)
if found is None and hasattr(self, 'output_field'):
return self.output_field.get_transform(lookup_name)
if found is not None and not issubclass(found, Transform):
return None
return found
@staticmethod
def merge_dicts(dicts):
"""
Merge dicts in reverse to preference the order of the original list. e.g.,
merge_dicts([a, b]) will preference the keys in 'a' over those in 'b'.
"""
merged = {}
for d in reversed(dicts):
merged.update(d)
return merged
@classmethod
def _clear_cached_lookups(cls):
for subclass in subclasses(cls):
subclass.get_lookups.cache_clear()
@classmethod
def register_lookup(cls, lookup, lookup_name=None):
if lookup_name is None:
lookup_name = lookup.lookup_name
if 'class_lookups' not in cls.__dict__:
cls.class_lookups = {}
cls.class_lookups[lookup_name] = lookup
cls._clear_cached_lookups()
return lookup
@classmethod
def _unregister_lookup(cls, lookup, lookup_name=None):
"""
Remove given lookup from cls lookups. For use in tests only as it's
not thread-safe.
"""
if lookup_name is None:
lookup_name = lookup.lookup_name
del cls.class_lookups[lookup_name]
def select_related_descend(field, restricted, requested, load_fields, reverse=False):
"""
Return True if this field should be used to descend deeper for
select_related() purposes. Used by both the query construction code
(sql.query.fill_related_selections()) and the model instance creation code
(query.get_klass_info()).
Arguments:
* field - the field to be checked
* restricted - a boolean field, indicating if the field list has been
manually restricted using a requested clause)
* requested - The select_related() dictionary.
* load_fields - the set of fields to be loaded on this model
* reverse - boolean, True if we are checking a reverse select related
"""
if not field.remote_field:
return False
if field.remote_field.parent_link and not reverse:
return False
if restricted:
if reverse and field.related_query_name() not in requested:
return False
if not reverse and field.name not in requested:
return False
if not restricted and field.null:
return False
if load_fields:
if field.attname not in load_fields:
if restricted and field.name in requested:
raise InvalidQuery("Field %s.%s cannot be both deferred"
" and traversed using select_related"
" at the same time." %
(field.model._meta.object_name, field.name))
return True
def refs_expression(lookup_parts, annotations):
"""
Check if the lookup_parts contains references to the given annotations set.
Because the LOOKUP_SEP is contained in the default annotation names, check
each prefix of the lookup_parts for a match.
"""
for n in range(1, len(lookup_parts) + 1):
level_n_lookup = LOOKUP_SEP.join(lookup_parts[0:n])
if level_n_lookup in annotations and annotations[level_n_lookup]:
return annotations[level_n_lookup], lookup_parts[n:]
return False, ()
def check_rel_lookup_compatibility(model, target_opts, field):
"""
Check that self.model is compatible with target_opts. Compatibility
is OK if:
1) model and opts match (where proxy inheritance is removed)
2) model is parent of opts' model or the other way around
"""
def check(opts):
return (
model._meta.concrete_model == opts.concrete_model or
opts.concrete_model in model._meta.get_parent_list() or
model in opts.get_parent_list()
)
# If the field is a primary key, then doing a query against the field's
# model is ok, too. Consider the case:
# class Restaurant(models.Model):
# place = OneToOneField(Place, primary_key=True):
# Restaurant.objects.filter(pk__in=Restaurant.objects.all()).
# If we didn't have the primary key check, then pk__in (== place__in) would
# give Place's opts as the target opts, but Restaurant isn't compatible
# with that. This logic applies only to primary keys, as when doing __in=qs,
# we are going to turn this into __in=qs.values('pk') later on.
return (
check(target_opts) or
(getattr(field, 'primary_key', False) and check(field.model._meta))
)
class FilteredRelation:
"""Specify custom filtering in the ON clause of SQL joins."""
def __init__(self, relation_name, *, condition=Q()):
if not relation_name:
raise ValueError('relation_name cannot be empty.')
self.relation_name = relation_name
self.alias = None
if not isinstance(condition, Q):
raise ValueError('condition argument must be a Q() instance.')
self.condition = condition
self.path = []
def __eq__(self, other):
return (
isinstance(other, self.__class__) and
self.relation_name == other.relation_name and
self.alias == other.alias and
self.condition == other.condition
)
def clone(self):
clone = FilteredRelation(self.relation_name, condition=self.condition)
clone.alias = self.alias
clone.path = self.path[:]
return clone
def resolve_expression(self, *args, **kwargs):
"""
QuerySet.annotate() only accepts expression-like arguments
(with a resolve_expression() method).
"""
raise NotImplementedError('FilteredRelation.resolve_expression() is unused.')
def as_sql(self, compiler, connection):
# Resolve the condition in Join.filtered_relation.
query = compiler.query
where = query.build_filtered_relation_q(self.condition, reuse=set(self.path))
return compiler.compile(where)
|
d0032de48a1a172483dcfbeffdf60d4fafcccbc00067db73258447ce449ad805 | import copy
import datetime
import inspect
from decimal import Decimal
from django.core.exceptions import EmptyResultSet, FieldError
from django.db import connection
from django.db.models import fields
from django.db.models.query_utils import Q
from django.db.utils import NotSupportedError
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 = '>>'
def _combine(self, other, connector, reversed):
if not hasattr(other, 'resolve_expression'):
# everything must be resolvable to an expression
if isinstance(other, datetime.timedelta):
other = DurationValue(other, output_field=fields.DurationField())
else:
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):
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 __or__(self, 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."
)
@deconstructible
class BaseExpression:
"""Base class for all query expressions."""
# 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 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:
yield from expr.flatten()
@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):
value = type(value)
else:
value = make_hashable(value)
identity.append((arg, value))
return tuple(identity)
def __eq__(self, other):
return isinstance(other, BaseExpression) and other.identity == self.identity
def __hash__(self):
return hash(self.identity)
class Expression(BaseExpression, Combinable):
"""An expression that can be combined with other expressions."""
pass
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 as_sql(self, compiler, connection):
try:
lhs_output = self.lhs.output_field
except FieldError:
lhs_output = None
try:
rhs_output = self.rhs.output_field
except FieldError:
rhs_output = None
if (not connection.features.has_native_duration_field and
((lhs_output and lhs_output.get_internal_type() == 'DurationField') or
(rhs_output and rhs_output.get_internal_type() == 'DurationField'))):
return DurationExpression(self.lhs, self.connector, self.rhs).as_sql(compiler, connection)
if (lhs_output and rhs_output and self.connector == self.SUB and
lhs_output.get_internal_type() in {'DateField', 'DateTimeField', 'TimeField'} and
lhs_output.get_internal_type() == rhs_output.get_internal_type()):
return TemporalSubtraction(self.lhs, self.rhs).as_sql(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):
c = self.copy()
c.is_summary = summarize
c.lhs = c.lhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.rhs = c.rhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
class DurationExpression(CombinedExpression):
def compile(self, side, compiler, connection):
if not isinstance(side, DurationValue):
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):
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
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, connection)
rhs = compiler.compile(self.rhs, connection)
return connection.ops.subtract_temporals(self.lhs.output_field.get_internal_type(), lhs, rhs)
@deconstructible
class F(Combinable):
"""An object capable of resolving references to existing query objects."""
# Can the expression be used in a WHERE clause?
filterable = True
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, simple_col=False):
return query.resolve_ref(self.name, allow_joins, reuse, summarize, simple_col)
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 relabeled_clone(self, relabels):
return self
class OuterRef(F):
def resolve_expression(self, query=None, allow_joins=True, reuse=None,
summarize=False, for_save=False, simple_col=False):
if isinstance(self.name, self.__class__):
return self.name
return ResolvedOuterRef(self.name)
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:
arg_sql, arg_params = compiler.compile(arg)
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
class Value(Expression):
"""Represent a wrapped value as a node within an expression."""
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 "{}({})".format(self.__class__.__name__, self.value)
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 []
class DurationValue(Value):
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
if connection.features.has_native_duration_field:
return super().as_sql(compiler, connection)
return connection.ops.date_interval_sql(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]
class Star(Expression):
def __repr__(self):
return "'*'"
def as_sql(self, compiler, connection):
return '*', []
class Random(Expression):
output_field = fields.FloatField()
def __repr__(self):
return "Random()"
def as_sql(self, compiler, connection):
return connection.ops.random_function_sql(), []
class Col(Expression):
contains_column_references = True
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):
return "{}({}, {})".format(
self.__class__.__name__, self.alias, self.target)
def as_sql(self, compiler, connection):
qn = compiler.quote_name_unless_alias
return "%s.%s" % (qn(self.alias), qn(self.target.column)), []
def relabeled_clone(self, relabels):
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 SimpleCol(Expression):
"""
Represents the SQL of a column name without the table name.
This variant of Col doesn't include the table name (or an alias) to
avoid a syntax error in check constraints.
"""
contains_column_references = True
def __init__(self, target, output_field=None):
if output_field is None:
output_field = target
super().__init__(output_field=output_field)
self.target = target
def __repr__(self):
return '{}({})'.format(self.__class__.__name__, self.target)
def as_sql(self, compiler, connection):
qn = compiler.quote_name_unless_alias
return qn(self.target.column), []
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 an
ordering 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)
class ExpressionWrapper(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 as_sql(self, compiler, connection):
return self.expression.as_sql(compiler, connection)
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.expression)
class When(Expression):
template = 'WHEN %(condition)s THEN %(result)s'
def __init__(self, condition=None, then=None, **lookups):
if lookups and condition is None:
condition, lookups = Q(**lookups), None
if condition is None or not getattr(condition, 'conditional', False) or lookups:
raise TypeError("__init__() takes either a Q object or lookups as keyword arguments")
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
class Case(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
class Subquery(Expression):
"""
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
def __init__(self, queryset, output_field=None, **extra):
self.query = queryset.query
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 as_sql(self, compiler, connection, template=None, **extra_context):
connection.ops.check_expression_support(self)
template_params = {**self.extra, **extra_context}
subquery_sql, sql_params = self.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 alias:
return [Ref(alias, self)]
return []
class Exists(Subquery):
template = 'EXISTS(%(subquery)s)'
output_field = fields.BooleanField()
def __init__(self, queryset, negated=False, **kwargs):
# As a performance optimization, remove ordering since EXISTS doesn't
# care about it, just whether or not a row matches.
queryset = queryset.order_by()
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):
sql, params = super().as_sql(compiler, connection, template, **extra_context)
if self.negated:
sql = 'NOT {}'.format(sql)
return sql, params
def as_oracle(self, compiler, connection, template=None, **extra_context):
# Oracle doesn't allow EXISTS() in the SELECT list, so wrap it with a
# CASE WHEN expression. Change the template since the When expression
# requires a left hand side (column) to compare against.
sql, params = self.as_sql(compiler, connection, template, **extra_context)
sql = 'CASE WHEN {} THEN 1 ELSE 0 END'.format(sql)
return sql, params
class OrderBy(BaseExpression):
template = '%(expression)s %(ordering)s'
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):
if not template:
if self.nulls_last:
template = '%s NULLS LAST' % self.template
elif self.nulls_first:
template = '%s NULLS FIRST' % self.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,
}
template = template or self.template
params *= template.count('%(expression)s')
return (template % placeholders).rstrip(), params
def as_sqlite(self, compiler, connection):
template = None
if self.nulls_last:
template = '%(expression)s IS NULL, %(expression)s %(ordering)s'
elif self.nulls_first:
template = '%(expression)s IS NOT NULL, %(expression)s %(ordering)s'
return self.as_sql(compiler, connection, template=template)
def as_mysql(self, compiler, connection):
template = None
if self.nulls_last:
template = 'IF(ISNULL(%(expression)s),1,0), %(expression)s %(ordering)s '
elif self.nulls_first:
template = 'IF(ISNULL(%(expression)s),0,1), %(expression)s %(ordering)s '
return self.as_sql(compiler, connection, template=template)
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(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 = ExpressionList(*self.order_by)
elif not isinstance(self.order_by, BaseExpression):
raise ValueError(
'order_by must be either an Expression or a sequence of '
'expressions.'
)
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.extend(sql_expr)
window_params.extend(sql_params)
if self.order_by is not None:
window_sql.append(' ORDER BY ')
order_sql, order_params = compiler.compile(self.order_by)
window_sql.extend(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 __str__(self):
return '{} OVER ({}{}{})'.format(
str(self.source_expression),
'PARTITION BY ' + str(self.partition_by) if self.partition_by else '',
'ORDER BY ' + str(self.order_by) if self.order_by else '',
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)
|
54f7fe9c7212c64bbf85bb10a9210cfebf3bec5a8baba453e521b8b8d35a0e41 | from collections import Counter
from itertools import chain
from operator import attrgetter
from django.db import IntegrityError, connections, transaction
from django.db.models import signals, sql
class ProtectedError(IntegrityError):
def __init__(self, msg, protected_objects):
self.protected_objects = protected_objects
super().__init__(msg, protected_objects)
def CASCADE(collector, field, sub_objs, using):
collector.collect(sub_objs, source=field.remote_field.model,
source_attr=field.name, nullable=field.null)
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 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):
self.using = using
# Initially, {model: {instances}}, later values become lists.
self.data = {}
self.field_updates = {} # {model: {(field, value): {instances}}}
# 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 = {} # {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.setdefault(model, set())
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:
if reverse_dependency:
source, model = model, source
self.dependencies.setdefault(
source._meta.concrete_model, set()).add(model._meta.concrete_model)
return new_objs
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.setdefault(
model, {}).setdefault(
(field, value), set()).update(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 = type(objs)
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, field):
"""
Return the objs in suitably sized batches for the used connection.
"""
conn_batch_size = max(
connections[self.using].ops.bulk_batch_size([field.name], 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):
"""
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 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)
if collect_related:
if keep_parents:
parents = set(model._meta.get_parent_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
batches = self.get_del_batches(new_objs, field)
for batch in batches:
sub_objs = self.related_objects(related, batch)
if self.can_fast_delete(sub_objs, from_field=field):
self.fast_deletes.append(sub_objs)
else:
related_model = related.related_model
# 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:
field.remote_field.on_delete(self, field, sub_objs, self.using)
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)
def related_objects(self, related, objs):
"""
Get a QuerySet of objects related to `objs` via the relation `related`.
"""
return related.related_model._base_manager.using(self.using).filter(
**{"%s__in" % related.field.name: objs}
)
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():
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
)
# fast deletes
for qs in self.fast_deletes:
count = qs._raw_delete(using=self.using)
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)
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
)
# 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)
|
2f6099d7ed00066e2f4acc707f235585d2753a4904e54c7de4dba56208806088 | import itertools
import math
from copy import copy
from django.core.exceptions import EmptyResultSet
from django.db.models.expressions import Func, Value
from django.db.models.fields import DateTimeField, Field, IntegerField
from django.db.models.query_utils import RegisterLookupMixin
from django.utils.datastructures import OrderedSet
from django.utils.functional import cached_property
class Lookup:
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()
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 Query # avoid circular import
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 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 hasattr(self.rhs, 'resolve_expression'):
return self.rhs
if self.prepare_rhs and hasattr(self.lhs.output_field, 'get_prep_value'):
return self.lhs.output_field.get_prep_value(self.rhs)
return self.rhs
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)
return compiler.compile(lhs)
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'):
return compiler.compile(value)
else:
return self.get_db_prep_lookup(value, connection)
def rhs_is_direct_value(self):
return not hasattr(self.rhs, 'as_sql')
def relabeled_clone(self, relabels):
new = copy(self)
new.lhs = new.lhs.relabeled_clone(relabels)
if hasattr(new.rhs, 'relabeled_clone'):
new.rhs = new.rhs.relabeled_clone(relabels)
return new
def get_group_by_cols(self, alias=None):
cols = self.lhs.get_group_by_cols()
if hasattr(self.rhs, 'get_group_by_cols'):
cols.extend(self.rhs.get_group_by_cols())
return cols
def as_sql(self, compiler, connection):
raise NotImplementedError
@cached_property
def contains_aggregate(self):
return self.lhs.contains_aggregate or getattr(self.rhs, 'contains_aggregate', False)
@cached_property
def contains_over_clause(self):
return self.lhs.contains_over_clause or getattr(self.rhs, 'contains_over_clause', False)
@property
def is_summary(self):
return self.lhs.is_summary or getattr(self.rhs, 'is_summary', False)
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 output_field of the 'field' attribute.
field = getattr(self.lhs.output_field, '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 = param.as_sql(compiler, connection)
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)
@Field.register_lookup
class Exact(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'exact'
def process_rhs(self, compiler, connection):
from django.db.models.sql.query import Query
if isinstance(self.rhs, Query):
if self.rhs.has_limit_one():
# The subquery must select only the pk.
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().process_rhs(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 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():
try:
rhs = OrderedSet(self.rhs)
except TypeError: # Unhashable items in self.rhs
rhs = self.rhs
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)
else:
if not getattr(self.rhs, 'has_select_fields', True):
self.rhs.clear_select_clause()
self.rhs.add_fields(['pk'])
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):
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):
output_field = self.lhs.lhs.output_field
if isinstance(output_field, DateTimeField):
bounds = connection.ops.year_lookup_bounds_for_datetime_field(year)
else:
bounds = connection.ops.year_lookup_bounds_for_date_field(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,)
|
243ebaba007553de7b09872b18bc4a32aef75e55130b5632f4d6926514d901d6 | from django.db.models.query_utils import Q
from django.db.models.sql.query import Query
__all__ = ['CheckConstraint', 'UniqueConstraint']
class BaseConstraint:
def __init__(self, name):
self.name = name
def constraint_sql(self, model, schema_editor):
raise NotImplementedError('This method must be implemented by a subclass.')
def create_sql(self, model, schema_editor):
raise NotImplementedError('This method must be implemented by a subclass.')
def remove_sql(self, model, schema_editor):
raise NotImplementedError('This method must be implemented by a subclass.')
def deconstruct(self):
path = '%s.%s' % (self.__class__.__module__, self.__class__.__name__)
path = path.replace('django.db.models.constraints', 'django.db.models')
return (path, (), {'name': self.name})
def clone(self):
_, args, kwargs = self.deconstruct()
return self.__class__(*args, **kwargs)
class CheckConstraint(BaseConstraint):
def __init__(self, *, check, name):
self.check = check
super().__init__(name)
def _get_check_sql(self, model, schema_editor):
query = Query(model=model)
where = query.build_where(self.check)
compiler = query.get_compiler(connection=schema_editor.connection)
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):
check = self._get_check_sql(model, schema_editor)
return schema_editor._check_sql(self.name, check)
def create_sql(self, model, schema_editor):
check = self._get_check_sql(model, schema_editor)
return schema_editor._create_check_sql(model, self.name, check)
def remove_sql(self, model, schema_editor):
return schema_editor._delete_check_sql(model, self.name)
def __repr__(self):
return "<%s: check='%s' name=%r>" % (self.__class__.__name__, self.check, self.name)
def __eq__(self, other):
return (
isinstance(other, CheckConstraint) and
self.name == other.name and
self.check == other.check
)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
kwargs['check'] = self.check
return path, args, kwargs
class UniqueConstraint(BaseConstraint):
def __init__(self, *, fields, name, condition=None):
if not fields:
raise ValueError('At least one field is required to define a unique constraint.')
if not isinstance(condition, (type(None), Q)):
raise ValueError('UniqueConstraint.condition must be a Q instance.')
self.fields = tuple(fields)
self.condition = condition
super().__init__(name)
def _get_condition_sql(self, model, schema_editor):
if self.condition is None:
return None
query = Query(model=model)
where = query.build_where(self.condition)
compiler = query.get_compiler(connection=schema_editor.connection)
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):
fields = [model._meta.get_field(field_name).column for field_name in self.fields]
condition = self._get_condition_sql(model, schema_editor)
return schema_editor._unique_sql(model, fields, self.name, condition=condition)
def create_sql(self, model, schema_editor):
fields = [model._meta.get_field(field_name).column for field_name in self.fields]
condition = self._get_condition_sql(model, schema_editor)
return schema_editor._create_unique_sql(model, fields, self.name, condition=condition)
def remove_sql(self, model, schema_editor):
condition = self._get_condition_sql(model, schema_editor)
return schema_editor._delete_unique_sql(model, self.name, condition=condition)
def __repr__(self):
return '<%s: fields=%r name=%r%s>' % (
self.__class__.__name__, self.fields, self.name,
'' if self.condition is None else ' condition=%s' % self.condition,
)
def __eq__(self, other):
return (
isinstance(other, UniqueConstraint) and
self.name == other.name and
self.fields == other.fields and
self.condition == other.condition
)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
kwargs['fields'] = self.fields
if self.condition:
kwargs['condition'] = self.condition
return path, args, kwargs
|
6f24f791d03138ccbbbaa221fc3d82831c800416f668da0f29c1897ccf20384a | """
Helpers to manipulate deferred DDL statements that might need to be adjusted or
discarded within when executing a migration.
"""
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):
try:
return self.quote_name(column) + self.col_suffixes[idx]
except IndexError:
return self.quote_name(column)
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):
try:
col = self.quote_name(column) + self.col_suffixes[idx]
except IndexError:
col = self.quote_name(column)
# Index.__init__() guarantees that self.opclasses is the same
# length as self.columns.
return '{} {}'.format(col, self.opclasses[idx])
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
|
f91451904e8110cd62294638cef8d9f22b6cc1f1e1c5ac4755dd3b6aef5c0ebd | import datetime
import decimal
import functools
import hashlib
import logging
import time
from contextlib import contextmanager
from django.conf import settings
from django.db.utils import NotSupportedError
from django.utils.timezone import utc
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',
duration,
sql,
params,
extra={'duration': duration, 'sql': sql, 'params': params},
)
###############################################
# 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'
tzinfo = utc if settings.USE_TZ else None
return datetime.datetime(
int(dates[0]), int(dates[1]), int(dates[2]),
int(times[0]), int(times[1]), int(seconds),
int((microseconds + '000000')[:6]), tzinfo
)
###############################################
# Converters from Python to database (string) #
###############################################
def split_identifier(identifier):
"""
Split a 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 a 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 = hashlib.md5()
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
|
e3c56858d997795752aa732a97ec1d5951a6bfc056a5f14bcf6a47dc8e510c26 | from .fields import AddField, AlterField, RemoveField, RenameField
from .models import (
AddConstraint, AddIndex, AlterIndexTogether, AlterModelManagers,
AlterModelOptions, AlterModelTable, AlterOrderWithRespectTo,
AlterUniqueTogether, CreateModel, DeleteModel, RemoveConstraint,
RemoveIndex, RenameModel,
)
from .special import RunPython, RunSQL, SeparateDatabaseAndState
__all__ = [
'CreateModel', 'DeleteModel', 'AlterModelTable', 'AlterUniqueTogether',
'RenameModel', 'AlterIndexTogether', 'AlterModelOptions', 'AddIndex',
'RemoveIndex', 'AddField', 'RemoveField', 'AlterField', 'RenameField',
'AddConstraint', 'RemoveConstraint',
'SeparateDatabaseAndState', 'RunSQL', 'RunPython',
'AlterOrderWithRespectTo', 'AlterModelManagers',
]
|
78deb3bd5d2b492021625d219d8c9e5745209614932d0b67eacd37dcd4cc7af7 | from django.db import models
from django.db.migrations.operations.base import Operation
from django.db.migrations.state import ModelState
from django.db.models.options import normalize_together
from django.utils.functional import cached_property
from .fields import (
AddField, AlterField, FieldOperation, RemoveField, RenameField,
)
from .utils import ModelTuple, field_references_model
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=None):
return name.lower() == self.name_lower
def reduce(self, operation, app_label=None):
return (
super().reduce(operation, app_label=app_label) or
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)
def references_model(self, name, app_label=None):
name_lower = name.lower()
if name_lower == self.name_lower:
return True
# Check we didn't inherit from the model
model_tuple = ModelTuple(app_label, name_lower)
for base in self.bases:
if (base is not models.Model and isinstance(base, (models.base.ModelBase, str)) and
ModelTuple.from_model(base) == model_tuple):
return True
# Check we have no FKs/M2Ms with it
for _name, field in self.fields:
if field_references_model(field, model_tuple):
return True
return False
def reduce(self, operation, app_label=None):
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:
return [
CreateModel(
self.name,
fields=self.fields,
options={**self.options, **operation.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=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=None):
# The deleted model could be referencing the specified model through
# related fields.
return True
def describe(self):
return "Delete model %s" % self.name
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):
# Add a new model.
renamed_model = state.models[app_label, self.old_name_lower].clone()
renamed_model.name = self.new_name
state.models[app_label, self.new_name_lower] = renamed_model
# Repoint all fields pointing to the old model to the new one.
old_model_tuple = ModelTuple(app_label, self.old_name_lower)
new_remote_model = '%s.%s' % (app_label, self.new_name)
to_reload = []
for (model_app_label, model_name), model_state in state.models.items():
model_changed = False
for index, (name, field) in enumerate(model_state.fields):
changed_field = None
remote_field = field.remote_field
if remote_field:
remote_model_tuple = ModelTuple.from_model(
remote_field.model, model_app_label, model_name
)
if remote_model_tuple == old_model_tuple:
changed_field = field.clone()
changed_field.remote_field.model = new_remote_model
through_model = getattr(remote_field, 'through', None)
if through_model:
through_model_tuple = ModelTuple.from_model(
through_model, model_app_label, model_name
)
if through_model_tuple == old_model_tuple:
if changed_field is None:
changed_field = field.clone()
changed_field.remote_field.through = new_remote_model
if changed_field:
model_state.fields[index] = name, changed_field
model_changed = True
if model_changed:
to_reload.append((model_app_label, model_name))
# Reload models related to old model before removing the old model.
state.reload_models(to_reload, delay=True)
# Remove the old model.
state.remove_model(app_label, self.old_name_lower)
state.reload_model(app_label, self.new_name_lower, delay=True)
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)
# Move the main table
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.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=None):
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)
def reduce(self, operation, app_label=None):
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=app_label) or
not operation.references_model(self.new_name, app_label)
)
class AlterModelTable(ModelOperation):
"""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.models[app_label, self.name_lower].options["db_table"] = self.table
state.reload_model(app_label, self.name_lower, delay=True)
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)"
)
def reduce(self, operation, app_label=None):
if isinstance(operation, (AlterModelTable, DeleteModel)) and self.name_lower == operation.name_lower:
return [operation]
return super().reduce(operation, app_label=app_label)
class ModelOptionOperation(ModelOperation):
def reduce(self, operation, app_label=None):
if isinstance(operation, (self.__class__, DeleteModel)) and self.name_lower == operation.name_lower:
return [operation]
return super().reduce(operation, app_label=app_label)
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):
model_state = state.models[app_label, self.name_lower]
model_state.options[self.option_name] = self.option_value
state.reload_model(app_label, self.name_lower, delay=True)
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=None):
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 ''))
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):
model_state = state.models[app_label, self.name_lower]
model_state.options['order_with_respect_to'] = self.order_with_respect_to
state.reload_model(app_label, self.name_lower, delay=True)
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=None):
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)
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):
model_state = state.models[app_label, self.name_lower]
model_state.options = {**model_state.options, **self.options}
for key in self.ALTER_OPTION_KEYS:
if key not in self.options:
model_state.options.pop(key, False)
state.reload_model(app_label, self.name_lower, delay=True)
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
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):
model_state = state.models[app_label, self.name_lower]
model_state.managers = list(self.managers)
state.reload_model(app_label, self.name_lower, delay=True)
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
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):
model_state = state.models[app_label, self.model_name_lower]
model_state.options[self.option_name] = [*model_state.options[self.option_name], self.index.clone()]
state.reload_model(app_label, self.model_name_lower, delay=True)
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):
return 'Create index %s on field(s) %s of model %s' % (
self.index.name,
', '.join(self.index.fields),
self.model_name,
)
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):
model_state = state.models[app_label, self.model_name_lower]
indexes = model_state.options[self.option_name]
model_state.options[self.option_name] = [idx for idx in indexes if idx.name != self.name]
state.reload_model(app_label, self.model_name_lower, delay=True)
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)
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):
model_state = state.models[app_label, self.model_name_lower]
model_state.options[self.option_name] = [*model_state.options[self.option_name], self.constraint]
state.reload_model(app_label, self.model_name_lower, delay=True)
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)
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):
model_state = state.models[app_label, self.model_name_lower]
constraints = model_state.options[self.option_name]
model_state.options[self.option_name] = [c for c in constraints if c.name != self.name]
state.reload_model(app_label, self.model_name_lower, delay=True)
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)
|
130686e8a82786396f22b15794517e58151a427f325f37e95b45449c9637f004 | from django.db import router
from django.db.models.fields.related import RECURSIVE_RELATIONSHIP_CONSTANT
class Operation:
"""
Base class for migration operations.
It's responsible for both mutating the in-memory model state
(see db/migrations/state.py) to represent what it performs, as well
as actually performing it against a live database.
Note that some operations won't modify memory state at all (e.g. data
copying operations), and some will need their modifications to be
optionally specified by the user (e.g. custom Python code snippets)
Due to the way this class deals with deconstruction, it should be
considered immutable.
"""
# If this migration can be run in reverse.
# Some operations are impossible to reverse, like deleting data.
reversible = True
# Can this migration be represented as SQL? (things like RunPython cannot)
reduces_to_sql = True
# Should this operation be forced as atomic even on backends with no
# DDL transaction support (i.e., does it have no DDL, like RunPython)
atomic = False
# Should this operation be considered safe to elide and optimize across?
elidable = False
serialization_expand_args = []
def __new__(cls, *args, **kwargs):
# We capture the arguments to make returning them trivial
self = object.__new__(cls)
self._constructor_args = (args, kwargs)
return self
def deconstruct(self):
"""
Return a 3-tuple of class import path (or just name if it lives
under django.db.migrations), positional arguments, and keyword
arguments.
"""
return (
self.__class__.__name__,
self._constructor_args[0],
self._constructor_args[1],
)
def state_forwards(self, app_label, state):
"""
Take the state from the previous migration, and mutate it
so that it matches what this migration would perform.
"""
raise NotImplementedError('subclasses of Operation must provide a state_forwards() method')
def database_forwards(self, app_label, schema_editor, from_state, to_state):
"""
Perform the mutation on the database schema in the normal
(forwards) direction.
"""
raise NotImplementedError('subclasses of Operation must provide a database_forwards() method')
def database_backwards(self, app_label, schema_editor, from_state, to_state):
"""
Perform the mutation on the database schema in the reverse
direction - e.g. if this were CreateModel, it would in fact
drop the model's table.
"""
raise NotImplementedError('subclasses of Operation must provide a database_backwards() method')
def describe(self):
"""
Output a brief summary of what the action does.
"""
return "%s: %s" % (self.__class__.__name__, self._constructor_args)
def references_model(self, name, app_label=None):
"""
Return True if there is a chance this operation references the given
model name (as a string), with an optional app label for accuracy.
Used for optimization. If in doubt, return True;
returning a false positive will merely make the optimizer a little
less efficient, while returning a false negative may result in an
unusable optimized migration.
"""
return True
def references_field(self, model_name, name, app_label=None):
"""
Return True if there is a chance this operation references the given
field name, with an optional app label for accuracy.
Used for optimization. If in doubt, return True.
"""
return self.references_model(model_name, app_label)
def allow_migrate_model(self, connection_alias, model):
"""
Return whether or not a model may be migrated.
This is a thin wrapper around router.allow_migrate_model() that
preemptively rejects any proxy, swapped out, or unmanaged model.
"""
if not model._meta.can_migrate(connection_alias):
return False
return router.allow_migrate_model(connection_alias, model)
def reduce(self, operation, app_label=None):
"""
Return either a list of operations the actual operation should be
replaced with or a boolean that indicates whether or not the specified
operation can be optimized across.
"""
if self.elidable:
return [operation]
elif operation.elidable:
return [self]
return False
def _get_model_tuple(self, remote_model, app_label, model_name):
if remote_model == RECURSIVE_RELATIONSHIP_CONSTANT:
return app_label, model_name.lower()
elif '.' in remote_model:
return tuple(remote_model.lower().split('.'))
else:
return app_label, remote_model.lower()
def __repr__(self):
return "<%s %s%s>" % (
self.__class__.__name__,
", ".join(map(repr, self._constructor_args[0])),
",".join(" %s=%r" % x for x in self._constructor_args[1].items()),
)
|
cbcdce156b93ac58182f1032ef7ccd70963b5445c98e4241933e4b507116ca6d | from django.core.exceptions import FieldDoesNotExist
from django.db.models.fields import NOT_PROVIDED
from django.utils.functional import cached_property
from .base import Operation
from .utils import (
ModelTuple, field_references_model, is_referenced_by_foreign_key,
)
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=None):
name_lower = name.lower()
if name_lower == self.model_name_lower:
return True
if self.field:
return field_references_model(self.field, ModelTuple(app_label, name_lower))
return False
def references_field(self, model_name, name, app_label=None):
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:
model_tuple = ModelTuple(app_label, model_name_lower)
remote_field = self.field.remote_field
if remote_field:
if (ModelTuple.from_model(remote_field.model) == model_tuple and
(not hasattr(self.field, 'to_fields') or
name in self.field.to_fields or None in self.field.to_fields)):
return True
through = getattr(remote_field, 'through', None)
if (through and ModelTuple.from_model(through) == model_tuple and
(getattr(remote_field, 'through_fields', None) is None or
name in remote_field.through_fields)):
return True
return False
def reduce(self, operation, app_label=None):
return (
super().reduce(operation, app_label=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):
# If preserve default is off, don't use the default for future state
if not self.preserve_default:
field = self.field.clone()
field.default = NOT_PROVIDED
else:
field = self.field
state.models[app_label, self.model_name_lower].fields.append((self.name, field))
# Delay rendering of relationships if it's not a relational field
delay = not field.is_relation
state.reload_model(app_label, self.model_name_lower, delay=delay)
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)
def reduce(self, operation, app_label=None):
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=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):
new_fields = []
old_field = None
for name, instance in state.models[app_label, self.model_name_lower].fields:
if name != self.name:
new_fields.append((name, instance))
else:
old_field = instance
state.models[app_label, self.model_name_lower].fields = new_fields
# Delay rendering of relationships if it's not a relational field
delay = not old_field.is_relation
state.reload_model(app_label, self.model_name_lower, delay=delay)
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)
def reduce(self, operation, app_label=None):
from .models import DeleteModel
if isinstance(operation, DeleteModel) and operation.name_lower == self.model_name_lower:
return [operation]
return super().reduce(operation, app_label=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):
if not self.preserve_default:
field = self.field.clone()
field.default = NOT_PROVIDED
else:
field = self.field
state.models[app_label, self.model_name_lower].fields = [
(n, field if n == self.name else f)
for n, f in
state.models[app_label, self.model_name_lower].fields
]
# 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 is_referenced_by_foreign_key(state, self.model_name_lower, self.field, self.name)
)
state.reload_model(app_label, self.model_name_lower, delay=delay)
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)
def reduce(self, operation, app_label=None):
if isinstance(operation, RemoveField) and self.is_same_field_operation(operation):
return [operation]
elif isinstance(operation, RenameField) and self.is_same_field_operation(operation):
return [
operation,
AlterField(
model_name=self.model_name,
name=operation.new_name,
field=self.field,
),
]
return super().reduce(operation, app_label=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):
model_state = state.models[app_label, self.model_name_lower]
# Rename the field
fields = model_state.fields
found = False
delay = True
for index, (name, field) in enumerate(fields):
if not found and name == self.old_name:
fields[index] = (self.new_name, field)
found = True
# Fix from_fields to refer to the new field.
from_fields = getattr(field, 'from_fields', None)
if from_fields:
field.from_fields = tuple([
self.new_name if from_field_name == self.old_name else from_field_name
for from_field_name in from_fields
])
# Delay rendering of relationships if it's not a relational
# field and not referenced by a foreign key.
delay = delay and (
not field.is_relation and
not is_referenced_by_foreign_key(state, self.model_name_lower, field, self.name)
)
if not found:
raise FieldDoesNotExist(
"%s.%s has no field named '%s'" % (app_label, self.model_name, self.old_name)
)
# 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] = [
[self.new_name if n == self.old_name else n for n in together]
for together in options[option]
]
# Fix to_fields to refer to the new field.
model_tuple = app_label, self.model_name_lower
for (model_app_label, model_name), model_state in state.models.items():
for index, (name, field) in enumerate(model_state.fields):
remote_field = field.remote_field
if remote_field:
remote_model_tuple = self._get_model_tuple(
remote_field.model, model_app_label, model_name
)
if remote_model_tuple == model_tuple:
if getattr(remote_field, 'field_name', None) == self.old_name:
remote_field.field_name = self.new_name
to_fields = getattr(field, 'to_fields', None)
if to_fields:
field.to_fields = tuple([
self.new_name if to_field_name == self.old_name else to_field_name
for to_field_name in to_fields
])
state.reload_model(app_label, self.model_name_lower, delay=delay)
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)
def references_field(self, model_name, name, app_label=None):
return self.references_model(model_name) and (
name.lower() == self.old_name_lower or
name.lower() == self.new_name_lower
)
def reduce(self, operation, app_label=None):
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.new_name.
return (
super(FieldOperation, self).reduce(operation, app_label=app_label) or
not operation.references_field(self.model_name, self.new_name, app_label)
)
|
f9da57d9e209613c5eca359e75741af0706c35a0f0fd81b0ea345de735443faa | from collections import namedtuple
from django.db.models.fields.related import RECURSIVE_RELATIONSHIP_CONSTANT
def is_referenced_by_foreign_key(state, model_name_lower, field, field_name):
for state_app_label, state_model in state.models:
for _, f in state.models[state_app_label, state_model].fields:
if (f.related_model and
'%s.%s' % (state_app_label, model_name_lower) == f.related_model.lower() and
hasattr(f, 'to_fields')):
if (f.to_fields[0] is None and field.primary_key) or field_name in f.to_fields:
return True
return False
class ModelTuple(namedtuple('ModelTupleBase', ('app_label', 'model_name'))):
@classmethod
def from_model(cls, model, app_label=None, model_name=None):
"""
Take a model class or an 'app_label.ModelName' string and return a
ModelTuple('app_label', 'modelname'). The optional app_label and
model_name arguments are the defaults if "self" or "ModelName" are
passed.
"""
if isinstance(model, str):
if model == RECURSIVE_RELATIONSHIP_CONSTANT:
return cls(app_label, model_name)
if '.' in model:
return cls(*model.lower().split('.', 1))
return cls(app_label, model.lower())
return cls(model._meta.app_label, model._meta.model_name)
def __eq__(self, other):
if isinstance(other, ModelTuple):
# Consider ModelTuple equal if their model_name is equal and either
# one of them is missing an app_label.
return self.model_name == other.model_name and (
self.app_label is None or other.app_label is None or self.app_label == other.app_label
)
return super().__eq__(other)
def field_references_model(field, model_tuple):
"""Return whether or not field references model_tuple."""
remote_field = field.remote_field
if remote_field:
if ModelTuple.from_model(remote_field.model) == model_tuple:
return True
through = getattr(remote_field, 'through', None)
if through and ModelTuple.from_model(through) == model_tuple:
return True
return False
|
c9df81b5beeaddc41aa57a26b670d47770b3d7fcea459ac72fc28335d40b9146 | import collections.abc
import copy
import datetime
import decimal
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
# When the _meta object was formalized, this exception was moved to
# django.core.exceptions. It is retained here for backwards compatibility
# purposes.
from django.core.exceptions import FieldDoesNotExist # NOQA
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', 'FieldDoesNotExist', 'FilePathField',
'FloatField', 'GenericIPAddressField', 'IPAddressField', 'IntegerField',
'NOT_PROVIDED', 'NullBooleanField', 'PositiveIntegerField',
'PositiveSmallIntegerField', 'SlugField', '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
# 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
app = model._meta.app_label
return '%s.%s.%s' % (app, model._meta.object_name, 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 []
def _check_choices(self):
if not self.choices:
return []
def is_value(value, accept_promise=True):
return isinstance(value, (str, Promise) if accept_promise else str) or not is_iterable(value)
if is_value(self.choices, accept_promise=False):
return [
checks.Error(
"'choices' must be an iterable (e.g., a list or tuple).",
obj=self,
id='fields.E004',
)
]
# 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(
is_value(value) and is_value(human_name)
for value, human_name in group_choices
):
break
except (TypeError, ValueError):
# No groups, choices in the form [value, display]
value, human_name = group_name, group_choices
if not is_value(value) or not is_value(human_name):
break
# Special case: choices=['ab']
if isinstance(choices_group, str):
break
else:
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, **kwargs):
app_label = self.model._meta.app_label
for db in connections:
if router.allow_migrate(db, app_label, model_name=self.model._meta.model_name):
return connections[db].validation.check_field(self, **kwargs)
return []
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 output_field is None:
output_field = self
if alias != self.model._meta.db_table or output_field != self:
from django.db.models.expressions import Col
return Col(alias, self, output_field)
else:
return self.cached_col
@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")
if path.startswith("django.db.models.fields.files"):
path = path.replace("django.db.models.fields.files", "django.db.models")
if path.startswith("django.db.models.fields.proxy"):
path = path.replace("django.db.models.fields.proxy", "django.db.models")
if 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
return NotImplemented
def __lt__(self, other):
# This is needed because bisect does not take a comparison function.
if isinstance(other, Field):
return self.creation_counter < other.creation_counter
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
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:
# Don't override classmethods with the descriptor. This means that
# if you have a classmethod and a field with the same name, then
# such fields can't be deferred (we don't have a check for this).
if not getattr(cls, self.attname, None):
setattr(cls, self.attname, DeferredAttribute(self.attname))
if self.choices is not None:
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'
)
return (blank_choice if include_blank else []) + [
(choice_func(x), str(x))
for x in rel_model._default_manager.complex_filter(limit_choices_to).order_by(*ordering)
]
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 AutoField(Field):
description = _("Integer")
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value must be an integer."),
}
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 get_internal_type(self):
return "AutoField"
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 rel_db_type(self, connection):
return IntegerField().db_type(connection=connection)
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 get_prep_value(self, value):
from django.db.models.expressions import OuterRef
value = super().get_prep_value(value)
if value is None or isinstance(value, OuterRef):
return value
return int(value)
def contribute_to_class(self, cls, name, **kwargs):
assert not cls._meta.auto_field, "Model %s can't have more than one AutoField." % cls._meta.label
super().contribute_to_class(cls, name, **kwargs)
cls._meta.auto_field = self
def formfield(self, **kwargs):
return None
class BigAutoField(AutoField):
description = _("Big (8 byte) integer")
def get_internal_type(self):
return "BigAutoField"
def rel_db_type(self, connection):
return BigIntegerField().db_type(connection=connection)
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})
class CharField(Field):
description = _("String (up to %(max_length)s)")
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.validators.append(validators.MaxLengthValidator(self.max_length))
def check(self, **kwargs):
return [
*super().check(**kwargs),
*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 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)
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',
}
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 []
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 []
now = timezone.now()
if not timezone.is_naive(now):
now = timezone.make_naive(now, timezone.utc)
value = self.default
if isinstance(value, datetime.datetime):
if not timezone.is_naive(value):
value = timezone.make_naive(value, timezone.utc)
value = value.date()
elif isinstance(value, datetime.date):
# Nothing to do, as dates don't have tz information
pass
else:
# No explicit date / datetime value -- no checks necessary
return []
offset = datetime.timedelta(days=1)
lower = (now - offset).date()
upper = (now + offset).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 []
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 []
now = timezone.now()
if not timezone.is_naive(now):
now = timezone.make_naive(now, timezone.utc)
value = self.default
if isinstance(value, datetime.datetime):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
upper = now + second_offset
if timezone.is_aware(value):
value = timezone.make_naive(value, timezone.utc)
elif isinstance(value, datetime.date):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
lower = datetime.datetime(lower.year, lower.month, lower.day)
upper = now + second_offset
upper = datetime.datetime(upper.year, upper.month, upper.day)
value = datetime.datetime(value.year, value.month, value.day)
else:
# No explicit date / datetime value -- no checks necessary
return []
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 []
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):
return self.context.create_decimal_from_float(value)
try:
return decimal.Decimal(value)
except decimal.InvalidOperation:
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
return float(value)
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
return int(value)
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 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)")
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
def get_internal_type(self):
return "NullBooleanField"
class PositiveIntegerRelDbTypeMixin:
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 IntegerField().db_type(connection=connection)
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, IntegerField):
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 SmallIntegerField(IntegerField):
description = _("Small integer")
def get_internal_type(self):
return "SmallIntegerField"
class TextField(Field):
description = _("Text")
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,
})
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 []
now = timezone.now()
if not timezone.is_naive(now):
now = timezone.make_naive(now, timezone.utc)
value = self.default
if isinstance(value, datetime.datetime):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
upper = now + second_offset
if timezone.is_aware(value):
value = timezone.make_naive(value, timezone.utc)
elif isinstance(value, datetime.time):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
upper = now + second_offset
value = datetime.datetime.combine(now.date(), value)
if timezone.is_aware(value):
value = timezone.make_naive(value, timezone.utc).time()
else:
# No explicit time / datetime value -- no checks necessary
return []
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 []
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,
})
|
2f276a2cd4f32427b242a1676647e526037a21d32c5dbd27cd5cdfd9de53bf18 | import functools
import inspect
from functools import partial
from django import forms
from django.apps import apps
from django.conf import SettingsReference
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 (
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
@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):
model = "%s.%s" % (
self.remote_field.model._meta.app_label,
self.remote_field.model._meta.object_name
)
return [
checks.Error(
"Field defines a relation with the model '%s', which has "
"been swapped out." % model,
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"
field_name = "%s.%s" % (opts.object_name, self.name) # i. e. "Model.field"
# 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:
clash_name = "%s.%s" % (rel_opts.object_name, clash_field.name) # i.e. "Target.model_set"
if not rel_is_hidden and clash_field.name == rel_name:
errors.append(
checks.Error(
"Reverse accessor 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.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:
clash_name = "%s.%s" % ( # i. e. "Model.m2m"
clash_field.related_model._meta.object_name,
clash_field.field.name)
if not rel_is_hidden and clash_field.get_accessor_name() == rel_name:
errors.append(
checks.Error(
"Reverse accessor for '%s' clashes with reverse accessor 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.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.remote_field.limit_choices_to:
kwargs['limit_choices_to'] = self.remote_field.limit_choices_to
if self.remote_field.related_name is not None:
kwargs['related_name'] = self.remote_field.related_name
if self.remote_field.related_query_name is not None:
kwargs['related_query_name'] = self.remote_field.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.get_path_info()[-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, **kwargs)
self.from_fields = from_fields
self.to_fields = to_fields
self.swappable = swappable
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
})
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=(
"Add unique=True on any of those fields or add at "
"least a subset of them to a unique_together constraint."
),
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 set unique=True because it is referenced by "
"a foreign key." % (model_name, field_name),
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
# Work out string form of "to"
if isinstance(self.remote_field.model, str):
kwargs['to'] = self.remote_field.model
else:
kwargs['to'] = "%s.%s" % (
self.remote_field.model._meta.app_label,
self.remote_field.model._meta.object_name,
)
# 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 == 'self'
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
@property
def related_fields(self):
if not hasattr(self, '_related_fields'):
self._related_fields = self.resolve_related_fields()
return self._related_fields
@property
def reverse_related_fields(self):
return [(rhs_field, lhs_field) for lhs_field, rhs_field in self.related_fields]
@property
def local_related_fields(self):
return tuple(lhs_field for lhs_field, rhs_field in self.related_fields)
@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, where_class, 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,
)]
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,
)]
@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.
"""
# 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:
assert isinstance(to, str), (
"%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, from_fields=['self'], 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._default_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 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,
})
def db_check(self, connection):
return []
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:
assert isinstance(to, str), (
"%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:
assert db_table is None, (
"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__(**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.limit_choices_to and self.remote_field.through and
not self.remote_field.through._meta.auto_created):
warnings.append(
checks.Warning(
'limit_choices_to has no effect on ManyToManyField '
'with a through model.',
obj=self,
id='fields.W343',
)
)
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
# Check symmetrical attribute.
if (self_referential and self.remote_field.symmetrical and
not self.remote_field.through._meta.auto_created):
errors.append(
checks.Error(
'Many-to-many fields with intermediate tables must not be symmetrical.',
obj=self,
id='fields.E332',
)
)
# 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 ForeignKey("self", symmetrical=False, through="%s").'
) % 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 ForeignKey("self", symmetrical=False, through="%s").'
) % 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
return [
checks.Error(
"The field's intermediary table '%s' clashes with the "
"table name of '%s'." % (m2m_db_table, clashing_obj),
obj=self,
id='fields.E340',
)
]
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'] = "%s.%s" % (
self.remote_field.model._meta.app_label,
self.remote_field.model._meta.object_name,
)
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'] = "%s.%s" % (
self.remote_field.through._meta.app_label,
self.remote_field.through._meta.object_name,
)
# 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.get_reverse_path_info()
join2infos = linkfield2.get_path_info(filtered_relation)
else:
join1infos = linkfield2.get_reverse_path_info()
join2infos = linkfield1.get_path_info(filtered_relation)
# 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)
def get_reverse_path_info(self, filtered_relation=None):
return self._get_path_info(direct=False, filtered_relation=filtered_relation)
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 == "self" 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_+" % (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}
|
cedf6597d27e52e1e9147f7171c89dff388d8cccd26a2d5c29796123d43f2fa5 | import datetime
import posixpath
from django import forms
from django.core import checks
from django.core.files.base import File
from django.core.files.images import ImageFile
from django.core.files.storage import default_storage
from django.db.models import signals
from django.db.models.fields import Field
from django.utils.translation import gettext_lazy as _
class FieldFile(File):
def __init__(self, instance, field, name):
super().__init__(None, name)
self.instance = instance
self.field = field
self.storage = field.storage
self._committed = True
def __eq__(self, other):
# Older code may be expecting FileField values to be simple strings.
# By overriding the == operator, it can remain backwards compatibility.
if hasattr(other, 'name'):
return self.name == other.name
return self.name == other
def __hash__(self):
return hash(self.name)
# The standard File contains most of the necessary properties, but
# FieldFiles can be instantiated without a name, so that needs to
# be checked for here.
def _require_file(self):
if not self:
raise ValueError("The '%s' attribute has no file associated with it." % self.field.name)
def _get_file(self):
self._require_file()
if getattr(self, '_file', None) is None:
self._file = self.storage.open(self.name, 'rb')
return self._file
def _set_file(self, file):
self._file = file
def _del_file(self):
del self._file
file = property(_get_file, _set_file, _del_file)
@property
def path(self):
self._require_file()
return self.storage.path(self.name)
@property
def url(self):
self._require_file()
return self.storage.url(self.name)
@property
def size(self):
self._require_file()
if not self._committed:
return self.file.size
return self.storage.size(self.name)
def open(self, mode='rb'):
self._require_file()
if getattr(self, '_file', None) is None:
self.file = self.storage.open(self.name, mode)
else:
self.file.open(mode)
return self
# open() doesn't alter the file's contents, but it does reset the pointer
open.alters_data = True
# In addition to the standard File API, FieldFiles have extra methods
# to further manipulate the underlying file, as well as update the
# associated model instance.
def save(self, name, content, save=True):
name = self.field.generate_filename(self.instance, name)
self.name = self.storage.save(name, content, max_length=self.field.max_length)
setattr(self.instance, self.field.name, self.name)
self._committed = True
# Save the object because it has changed, unless save is False
if save:
self.instance.save()
save.alters_data = True
def delete(self, save=True):
if not self:
return
# Only close the file if it's already open, which we know by the
# presence of self._file
if hasattr(self, '_file'):
self.close()
del self.file
self.storage.delete(self.name)
self.name = None
setattr(self.instance, self.field.name, self.name)
self._committed = False
if save:
self.instance.save()
delete.alters_data = True
@property
def closed(self):
file = getattr(self, '_file', None)
return file is None or file.closed
def close(self):
file = getattr(self, '_file', None)
if file is not None:
file.close()
def __getstate__(self):
# FieldFile needs access to its associated model field and an instance
# it's attached to in order to work properly, but the only necessary
# data to be pickled is the file's name itself. Everything else will
# be restored later, by FileDescriptor below.
return {'name': self.name, 'closed': False, '_committed': True, '_file': None}
class FileDescriptor:
"""
The descriptor for the file attribute on the model instance. Return a
FieldFile when accessed so you can write code like::
>>> from myapp.models import MyModel
>>> instance = MyModel.objects.get(pk=1)
>>> instance.file.size
Assign a file object on assignment so you can do::
>>> with open('/path/to/hello.world') as f:
... instance.file = File(f)
"""
def __init__(self, field):
self.field = field
def __get__(self, instance, cls=None):
if instance is None:
return self
# This is slightly complicated, so worth an explanation.
# instance.file`needs to ultimately return some instance of `File`,
# probably a subclass. Additionally, this returned object needs to have
# the FieldFile API so that users can easily do things like
# instance.file.path and have that delegated to the file storage engine.
# Easy enough if we're strict about assignment in __set__, but if you
# peek below you can see that we're not. So depending on the current
# value of the field we have to dynamically construct some sort of
# "thing" to return.
# The instance dict contains whatever was originally assigned
# in __set__.
if self.field.name in instance.__dict__:
file = instance.__dict__[self.field.name]
else:
instance.refresh_from_db(fields=[self.field.name])
file = getattr(instance, self.field.name)
# If this value is a string (instance.file = "path/to/file") or None
# then we simply wrap it with the appropriate attribute class according
# to the file field. [This is FieldFile for FileFields and
# ImageFieldFile for ImageFields; it's also conceivable that user
# subclasses might also want to subclass the attribute class]. This
# object understands how to convert a path to a file, and also how to
# handle None.
if isinstance(file, str) or file is None:
attr = self.field.attr_class(instance, self.field, file)
instance.__dict__[self.field.name] = attr
# Other types of files may be assigned as well, but they need to have
# the FieldFile interface added to them. Thus, we wrap any other type of
# File inside a FieldFile (well, the field's attr_class, which is
# usually FieldFile).
elif isinstance(file, File) and not isinstance(file, FieldFile):
file_copy = self.field.attr_class(instance, self.field, file.name)
file_copy.file = file
file_copy._committed = False
instance.__dict__[self.field.name] = file_copy
# Finally, because of the (some would say boneheaded) way pickle works,
# the underlying FieldFile might not actually itself have an associated
# file. So we need to reset the details of the FieldFile in those cases.
elif isinstance(file, FieldFile) and not hasattr(file, 'field'):
file.instance = instance
file.field = self.field
file.storage = self.field.storage
# Make sure that the instance is correct.
elif isinstance(file, FieldFile) and instance is not file.instance:
file.instance = instance
# That was fun, wasn't it?
return instance.__dict__[self.field.name]
def __set__(self, instance, value):
instance.__dict__[self.field.name] = value
class FileField(Field):
# The class to wrap instance attributes in. Accessing the file object off
# the instance will always return an instance of attr_class.
attr_class = FieldFile
# The descriptor to use for accessing the attribute off of the class.
descriptor_class = FileDescriptor
description = _("File")
def __init__(self, verbose_name=None, name=None, upload_to='', storage=None, **kwargs):
self._primary_key_set_explicitly = 'primary_key' in kwargs
self.storage = storage or default_storage
self.upload_to = upload_to
kwargs.setdefault('max_length', 100)
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_primary_key(),
*self._check_upload_to(),
]
def _check_primary_key(self):
if self._primary_key_set_explicitly:
return [
checks.Error(
"'primary_key' is not a valid argument for a %s." % self.__class__.__name__,
obj=self,
id='fields.E201',
)
]
else:
return []
def _check_upload_to(self):
if isinstance(self.upload_to, str) and self.upload_to.startswith('/'):
return [
checks.Error(
"%s's 'upload_to' argument must be a relative path, not an "
"absolute path." % self.__class__.__name__,
obj=self,
id='fields.E202',
hint='Remove the leading slash.',
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 100:
del kwargs["max_length"]
kwargs['upload_to'] = self.upload_to
if self.storage is not default_storage:
kwargs['storage'] = self.storage
return name, path, args, kwargs
def get_internal_type(self):
return "FileField"
def get_prep_value(self, value):
value = super().get_prep_value(value)
# Need to convert File objects provided via a form to string for database insertion
if value is None:
return None
return str(value)
def pre_save(self, model_instance, add):
file = super().pre_save(model_instance, add)
if file and not file._committed:
# Commit the file to storage prior to saving the model
file.save(file.name, file.file, save=False)
return file
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
setattr(cls, self.name, self.descriptor_class(self))
def generate_filename(self, instance, filename):
"""
Apply (if callable) or prepend (if a string) upload_to to the filename,
then delegate further processing of the name to the storage backend.
Until the storage layer, all file paths are expected to be Unix style
(with forward slashes).
"""
if callable(self.upload_to):
filename = self.upload_to(instance, filename)
else:
dirname = datetime.datetime.now().strftime(self.upload_to)
filename = posixpath.join(dirname, filename)
return self.storage.generate_filename(filename)
def save_form_data(self, instance, data):
# Important: None means "no change", other false value means "clear"
# This subtle distinction (rather than a more explicit marker) is
# needed because we need to consume values that are also sane for a
# regular (non Model-) Form to find in its cleaned_data dictionary.
if data is not None:
# This value will be converted to str and stored in the
# database, so leaving False as-is is not acceptable.
setattr(instance, self.name, data or '')
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.FileField,
'max_length': self.max_length,
**kwargs,
})
class ImageFileDescriptor(FileDescriptor):
"""
Just like the FileDescriptor, but for ImageFields. The only difference is
assigning the width/height to the width_field/height_field, if appropriate.
"""
def __set__(self, instance, value):
previous_file = instance.__dict__.get(self.field.name)
super().__set__(instance, value)
# To prevent recalculating image dimensions when we are instantiating
# an object from the database (bug #11084), only update dimensions if
# the field had a value before this assignment. Since the default
# value for FileField subclasses is an instance of field.attr_class,
# previous_file will only be None when we are called from
# Model.__init__(). The ImageField.update_dimension_fields method
# hooked up to the post_init signal handles the Model.__init__() cases.
# Assignment happening outside of Model.__init__() will trigger the
# update right here.
if previous_file is not None:
self.field.update_dimension_fields(instance, force=True)
class ImageFieldFile(ImageFile, FieldFile):
def delete(self, save=True):
# Clear the image dimensions cache
if hasattr(self, '_dimensions_cache'):
del self._dimensions_cache
super().delete(save)
class ImageField(FileField):
attr_class = ImageFieldFile
descriptor_class = ImageFileDescriptor
description = _("Image")
def __init__(self, verbose_name=None, name=None, width_field=None, height_field=None, **kwargs):
self.width_field, self.height_field = width_field, height_field
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_image_library_installed(),
]
def _check_image_library_installed(self):
try:
from PIL import Image # NOQA
except ImportError:
return [
checks.Error(
'Cannot use ImageField because Pillow is not installed.',
hint=('Get Pillow at https://pypi.org/project/Pillow/ '
'or run command "python -m pip install Pillow".'),
obj=self,
id='fields.E210',
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.width_field:
kwargs['width_field'] = self.width_field
if self.height_field:
kwargs['height_field'] = self.height_field
return name, path, args, kwargs
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
# Attach update_dimension_fields so that dimension fields declared
# after their corresponding image field don't stay cleared by
# Model.__init__, see bug #11196.
# Only run post-initialization dimension update on non-abstract models
if not cls._meta.abstract:
signals.post_init.connect(self.update_dimension_fields, sender=cls)
def update_dimension_fields(self, instance, force=False, *args, **kwargs):
"""
Update field's width and height fields, if defined.
This method is hooked up to model's post_init signal to update
dimensions after instantiating a model instance. However, dimensions
won't be updated if the dimensions fields are already populated. This
avoids unnecessary recalculation when loading an object from the
database.
Dimensions can be forced to update with force=True, which is how
ImageFileDescriptor.__set__ calls this method.
"""
# Nothing to update if the field doesn't have dimension fields or if
# the field is deferred.
has_dimension_fields = self.width_field or self.height_field
if not has_dimension_fields or self.attname not in instance.__dict__:
return
# getattr will call the ImageFileDescriptor's __get__ method, which
# coerces the assigned value into an instance of self.attr_class
# (ImageFieldFile in this case).
file = getattr(instance, self.attname)
# Nothing to update if we have no file and not being forced to update.
if not file and not force:
return
dimension_fields_filled = not(
(self.width_field and not getattr(instance, self.width_field)) or
(self.height_field and not getattr(instance, self.height_field))
)
# When both dimension fields have values, we are most likely loading
# data from the database or updating an image field that already had
# an image stored. In the first case, we don't want to update the
# dimension fields because we are already getting their values from the
# database. In the second case, we do want to update the dimensions
# fields and will skip this return because force will be True since we
# were called from ImageFileDescriptor.__set__.
if dimension_fields_filled and not force:
return
# file should be an instance of ImageFieldFile or should be None.
if file:
width = file.width
height = file.height
else:
# No file, so clear dimensions fields.
width = None
height = None
# Update the width and height fields.
if self.width_field:
setattr(instance, self.width_field, width)
if self.height_field:
setattr(instance, self.height_field, height)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.ImageField,
**kwargs,
})
|
36860cbf89b478cce3817e5200e1b503f14f24aa6e873edd6599f9fa92511bfc | """
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.utils.functional import cached_property
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_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
return self.related_manager_cls(instance)
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 = 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.get_path_info()[-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:
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()
objs = list(objs)
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:
# 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,
)
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(**{'%s__in' % self.target_field_name: removed_vals})
if self.symmetrical:
symmetrical_filters = Q(**{self.target_field_name: self.related_val})
if removed_vals_filters:
symmetrical_filters &= Q(
**{'%s__in' % self.source_field_name: 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)
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. `through_defaults` aren't used here
# because of the system check error fields.E332: Many-to-many
# fields with intermediate tables must not be symmetrical.
if self.symmetrical:
self._add_items(self.target_field_name, self.source_field_name, *objs)
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 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(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 = (
connections[db].features.supports_ignore_conflicts and
self.through._meta.auto_created is not False
)
# 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.
through_defaults = through_defaults or {}
# If there aren't any objects, there is nothing to do.
if objs:
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
|
eaf27bc6dcabe0b3d51ea4e3e5658e6dab43de53c11e1e35f814221ff16805f8 | """
"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 . 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
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.get_path_info()[-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,
)
def get_choices(self, include_blank=True, blank_choice=BLANK_CHOICE_DASH, 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.
"""
return (blank_choice if include_blank else []) + [
(x.pk, str(x)) for x in self.related_model._default_manager.order_by(*ordering)
]
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, where_class, alias, related_alias):
return self.field.get_extra_restriction(where_class, 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):
return self.field.get_reverse_path_info(filtered_relation)
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 = self.__dict__.copy()
state.pop('related_model', None)
return state
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
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]
|
d4cbe712fd63ded585aae0fac6e6146f81c00b4afb8a73b0998653f2c977abdb | from django.db.models.expressions import Func, Value
from django.db.models.fields import IntegerField
from django.db.models.functions import Coalesce
from django.db.models.lookups import Transform
from django.db.utils import NotSupportedError
class BytesToCharFieldConversionMixin:
"""
Convert CharField results from bytes to str.
MySQL returns long data types (bytes) instead of chars when it can't
determine the length of the result string. For example:
LPAD(column1, CHAR_LENGTH(column2), ' ')
returns the LONGTEXT (bytes) instead of VARCHAR.
"""
def convert_value(self, value, expression, connection):
if connection.features.db_functions_convert_bytes_to_str:
if self.output_field.get_internal_type() == 'CharField' and isinstance(value, bytes):
return value.decode()
return super().convert_value(value, expression, connection)
class MySQLSHA2Mixin:
def as_mysql(self, compiler, connection, **extra_content):
return super().as_sql(
compiler,
connection,
template='SHA2(%%(expressions)s, %s)' % self.function[3:],
**extra_content,
)
class OracleHashMixin:
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler,
connection,
template=(
"LOWER(RAWTOHEX(STANDARD_HASH(UTL_I18N.STRING_TO_RAW("
"%(expressions)s, 'AL32UTF8'), '%(function)s')))"
),
**extra_context,
)
class PostgreSQLSHAMixin:
def as_postgresql(self, compiler, connection, **extra_content):
return super().as_sql(
compiler,
connection,
template="ENCODE(DIGEST(%(expressions)s, '%(function)s'), 'hex')",
function=self.function.lower(),
**extra_content,
)
class Chr(Transform):
function = 'CHR'
lookup_name = 'chr'
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection, function='CHAR',
template='%(function)s(%(expressions)s USING utf16)',
**extra_context
)
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection,
template='%(function)s(%(expressions)s USING NCHAR_CS)',
**extra_context
)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='CHAR', **extra_context)
class ConcatPair(Func):
"""
Concatenate two arguments together. This is used by `Concat` because not
all backend databases support more than two arguments.
"""
function = 'CONCAT'
def as_sqlite(self, compiler, connection, **extra_context):
coalesced = self.coalesce()
return super(ConcatPair, coalesced).as_sql(
compiler, connection, template='%(expressions)s', arg_joiner=' || ',
**extra_context
)
def as_mysql(self, compiler, connection, **extra_context):
# Use CONCAT_WS with an empty separator so that NULLs are ignored.
return super().as_sql(
compiler, connection, function='CONCAT_WS',
template="%(function)s('', %(expressions)s)",
**extra_context
)
def coalesce(self):
# null on either side results in null for expression, wrap with coalesce
c = self.copy()
c.set_source_expressions([
Coalesce(expression, Value('')) for expression in c.get_source_expressions()
])
return c
class Concat(Func):
"""
Concatenate text fields together. Backends that result in an entire
null expression when any arguments are null will wrap each argument in
coalesce functions to ensure a non-null result.
"""
function = None
template = "%(expressions)s"
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Concat must take at least two expressions')
paired = self._paired(expressions)
super().__init__(paired, **extra)
def _paired(self, expressions):
# wrap pairs of expressions in successive concat functions
# exp = [a, b, c, d]
# -> ConcatPair(a, ConcatPair(b, ConcatPair(c, d))))
if len(expressions) == 2:
return ConcatPair(*expressions)
return ConcatPair(expressions[0], self._paired(expressions[1:]))
class Left(Func):
function = 'LEFT'
arity = 2
def __init__(self, expression, length, **extra):
"""
expression: the name of a field, or an expression returning a string
length: the number of characters to return from the start of the string
"""
if not hasattr(length, 'resolve_expression'):
if length < 1:
raise ValueError("'length' must be greater than 0.")
super().__init__(expression, length, **extra)
def get_substr(self):
return Substr(self.source_expressions[0], Value(1), self.source_expressions[1])
def as_oracle(self, compiler, connection, **extra_context):
return self.get_substr().as_oracle(compiler, connection, **extra_context)
def as_sqlite(self, compiler, connection, **extra_context):
return self.get_substr().as_sqlite(compiler, connection, **extra_context)
class Length(Transform):
"""Return the number of characters in the expression."""
function = 'LENGTH'
lookup_name = 'length'
output_field = IntegerField()
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='CHAR_LENGTH', **extra_context)
class Lower(Transform):
function = 'LOWER'
lookup_name = 'lower'
class LPad(BytesToCharFieldConversionMixin, Func):
function = 'LPAD'
def __init__(self, expression, length, fill_text=Value(' '), **extra):
if not hasattr(length, 'resolve_expression') and length is not None and length < 0:
raise ValueError("'length' must be greater or equal to 0.")
super().__init__(expression, length, fill_text, **extra)
class LTrim(Transform):
function = 'LTRIM'
lookup_name = 'ltrim'
class MD5(OracleHashMixin, Transform):
function = 'MD5'
lookup_name = 'md5'
class Ord(Transform):
function = 'ASCII'
lookup_name = 'ord'
output_field = IntegerField()
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='ORD', **extra_context)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='UNICODE', **extra_context)
class Repeat(BytesToCharFieldConversionMixin, Func):
function = 'REPEAT'
def __init__(self, expression, number, **extra):
if not hasattr(number, 'resolve_expression') and number is not None and number < 0:
raise ValueError("'number' must be greater or equal to 0.")
super().__init__(expression, number, **extra)
def as_oracle(self, compiler, connection, **extra_context):
expression, number = self.source_expressions
length = None if number is None else Length(expression) * number
rpad = RPad(expression, length, expression)
return rpad.as_sql(compiler, connection, **extra_context)
class Replace(Func):
function = 'REPLACE'
def __init__(self, expression, text, replacement=Value(''), **extra):
super().__init__(expression, text, replacement, **extra)
class Reverse(Transform):
function = 'REVERSE'
lookup_name = 'reverse'
def as_oracle(self, compiler, connection, **extra_context):
# REVERSE in Oracle is undocumented and doesn't support multi-byte
# strings. Use a special subquery instead.
return super().as_sql(
compiler, connection,
template=(
'(SELECT LISTAGG(s) WITHIN GROUP (ORDER BY n DESC) FROM '
'(SELECT LEVEL n, SUBSTR(%(expressions)s, LEVEL, 1) s '
'FROM DUAL CONNECT BY LEVEL <= LENGTH(%(expressions)s)) '
'GROUP BY %(expressions)s)'
),
**extra_context
)
class Right(Left):
function = 'RIGHT'
def get_substr(self):
return Substr(self.source_expressions[0], self.source_expressions[1] * Value(-1))
class RPad(LPad):
function = 'RPAD'
class RTrim(Transform):
function = 'RTRIM'
lookup_name = 'rtrim'
class SHA1(OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = 'SHA1'
lookup_name = 'sha1'
class SHA224(MySQLSHA2Mixin, PostgreSQLSHAMixin, Transform):
function = 'SHA224'
lookup_name = 'sha224'
def as_oracle(self, compiler, connection, **extra_context):
raise NotSupportedError('SHA224 is not supported on Oracle.')
class SHA256(MySQLSHA2Mixin, OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = 'SHA256'
lookup_name = 'sha256'
class SHA384(MySQLSHA2Mixin, OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = 'SHA384'
lookup_name = 'sha384'
class SHA512(MySQLSHA2Mixin, OracleHashMixin, PostgreSQLSHAMixin, Transform):
function = 'SHA512'
lookup_name = 'sha512'
class StrIndex(Func):
"""
Return a positive integer corresponding to the 1-indexed position of the
first occurrence of a substring inside another string, or 0 if the
substring is not found.
"""
function = 'INSTR'
arity = 2
output_field = IntegerField()
def as_postgresql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='STRPOS', **extra_context)
class Substr(Func):
function = 'SUBSTRING'
def __init__(self, expression, pos, length=None, **extra):
"""
expression: the name of a field, or an expression returning a string
pos: an integer > 0, or an expression returning an integer
length: an optional number of characters to return
"""
if not hasattr(pos, 'resolve_expression'):
if pos < 1:
raise ValueError("'pos' must be greater than 0")
expressions = [expression, pos]
if length is not None:
expressions.append(length)
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='SUBSTR', **extra_context)
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='SUBSTR', **extra_context)
class Trim(Transform):
function = 'TRIM'
lookup_name = 'trim'
class Upper(Transform):
function = 'UPPER'
lookup_name = 'upper'
|
a2e47c5c0006380b0791c530221e91ad270d702af2f3fe9247ff613b71422e83 | """Database functions that do comparisons or type conversions."""
from django.db.models.expressions import Func, Value
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):
# MySQL doesn't support explicit cast to float.
template = '(%(expressions)s + 0.0)' if self.output_field.get_internal_type() == 'FloatField' else None
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)
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)
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 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 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)
|
c01bfcd5f11d078487ea6616073331bf92f6975d8432cc32f23dedb3b2784b54 | from .comparison import Cast, Coalesce, Greatest, Least, NullIf
from .datetime import (
Extract, ExtractDay, ExtractHour, ExtractIsoYear, ExtractMinute,
ExtractMonth, ExtractQuarter, ExtractSecond, ExtractWeek, ExtractWeekDay,
ExtractYear, Now, Trunc, TruncDate, TruncDay, TruncHour, TruncMinute,
TruncMonth, TruncQuarter, TruncSecond, TruncTime, TruncWeek, TruncYear,
)
from .math import (
Abs, ACos, ASin, ATan, ATan2, Ceil, Cos, Cot, Degrees, Exp, Floor, Ln, Log,
Mod, Pi, Power, Radians, Round, Sign, Sin, Sqrt, Tan,
)
from .text import (
MD5, SHA1, SHA224, SHA256, SHA384, SHA512, Chr, Concat, ConcatPair, Left,
Length, Lower, LPad, LTrim, Ord, Repeat, Replace, Reverse, Right, RPad,
RTrim, StrIndex, Substr, Trim, Upper,
)
from .window import (
CumeDist, DenseRank, FirstValue, Lag, LastValue, Lead, NthValue, Ntile,
PercentRank, Rank, RowNumber,
)
__all__ = [
# comparison and conversion
'Cast', 'Coalesce', 'Greatest', 'Least', 'NullIf',
# datetime
'Extract', 'ExtractDay', 'ExtractHour', 'ExtractMinute', 'ExtractMonth',
'ExtractQuarter', 'ExtractSecond', 'ExtractWeek', 'ExtractWeekDay',
'ExtractIsoYear', 'ExtractYear', 'Now', 'Trunc', 'TruncDate', 'TruncDay',
'TruncHour', 'TruncMinute', 'TruncMonth', 'TruncQuarter', 'TruncSecond',
'TruncMinute', 'TruncMonth', 'TruncQuarter', 'TruncSecond', 'TruncTime',
'TruncWeek', 'TruncYear',
# math
'Abs', 'ACos', 'ASin', 'ATan', 'ATan2', 'Ceil', 'Cos', 'Cot', 'Degrees',
'Exp', 'Floor', 'Ln', 'Log', 'Mod', 'Pi', 'Power', 'Radians', 'Round',
'Sign', 'Sin', 'Sqrt', 'Tan',
# text
'MD5', 'SHA1', 'SHA224', 'SHA256', 'SHA384', 'SHA512', 'Chr', 'Concat',
'ConcatPair', 'Left', 'Length', 'Lower', 'LPad', 'LTrim', 'Ord', 'Repeat',
'Replace', 'Reverse', 'Right', 'RPad', 'RTrim', 'StrIndex', 'Substr',
'Trim', 'Upper',
# window
'CumeDist', 'DenseRank', 'FirstValue', 'Lag', 'LastValue', 'Lead',
'NthValue', 'Ntile', 'PercentRank', 'Rank', 'RowNumber',
]
|
c8bd3b06586ed56b9dc4731b21f440d9b0485eec1979cf302cf6d6e8de5e3b27 | from django.db.models.expressions import Func
from django.db.models.fields import FloatField, IntegerField
__all__ = [
'CumeDist', 'DenseRank', 'FirstValue', 'Lag', 'LastValue', 'Lead',
'NthValue', 'Ntile', 'PercentRank', 'Rank', 'RowNumber',
]
class CumeDist(Func):
function = 'CUME_DIST'
output_field = FloatField()
window_compatible = True
class DenseRank(Func):
function = 'DENSE_RANK'
output_field = IntegerField()
window_compatible = True
class FirstValue(Func):
arity = 1
function = 'FIRST_VALUE'
window_compatible = True
class LagLeadFunction(Func):
window_compatible = True
def __init__(self, expression, offset=1, default=None, **extra):
if expression is None:
raise ValueError(
'%s requires a non-null source expression.' %
self.__class__.__name__
)
if offset is None or offset <= 0:
raise ValueError(
'%s requires a positive integer for the offset.' %
self.__class__.__name__
)
args = (expression, offset)
if default is not None:
args += (default,)
super().__init__(*args, **extra)
def _resolve_output_field(self):
sources = self.get_source_expressions()
return sources[0].output_field
class Lag(LagLeadFunction):
function = 'LAG'
class LastValue(Func):
arity = 1
function = 'LAST_VALUE'
window_compatible = True
class Lead(LagLeadFunction):
function = 'LEAD'
class NthValue(Func):
function = 'NTH_VALUE'
window_compatible = True
def __init__(self, expression, nth=1, **extra):
if expression is None:
raise ValueError('%s requires a non-null source expression.' % self.__class__.__name__)
if nth is None or nth <= 0:
raise ValueError('%s requires a positive integer as for nth.' % self.__class__.__name__)
super().__init__(expression, nth, **extra)
def _resolve_output_field(self):
sources = self.get_source_expressions()
return sources[0].output_field
class Ntile(Func):
function = 'NTILE'
output_field = IntegerField()
window_compatible = True
def __init__(self, num_buckets=1, **extra):
if num_buckets <= 0:
raise ValueError('num_buckets must be greater than 0.')
super().__init__(num_buckets, **extra)
class PercentRank(Func):
function = 'PERCENT_RANK'
output_field = FloatField()
window_compatible = True
class Rank(Func):
function = 'RANK'
output_field = IntegerField()
window_compatible = True
class RowNumber(Func):
function = 'ROW_NUMBER'
output_field = IntegerField()
window_compatible = True
|
47faef199c6a47d18486e014517b7ba09d9b72094ec821fab4fce53a0fbb0cda | import math
from django.db.models.expressions import Func
from django.db.models.fields import FloatField, IntegerField
from django.db.models.functions import Cast
from django.db.models.functions.mixins import (
FixDecimalInputMixin, NumericOutputFieldMixin,
)
from django.db.models.lookups import Transform
class Abs(Transform):
function = 'ABS'
lookup_name = 'abs'
class ACos(NumericOutputFieldMixin, Transform):
function = 'ACOS'
lookup_name = 'acos'
class ASin(NumericOutputFieldMixin, Transform):
function = 'ASIN'
lookup_name = 'asin'
class ATan(NumericOutputFieldMixin, Transform):
function = 'ATAN'
lookup_name = 'atan'
class ATan2(NumericOutputFieldMixin, Func):
function = 'ATAN2'
arity = 2
def as_sqlite(self, compiler, connection, **extra_context):
if not getattr(connection.ops, 'spatialite', False) or connection.ops.spatial_version >= (5, 0, 0):
return self.as_sql(compiler, connection)
# This function is usually ATan2(y, x), returning the inverse tangent
# of y / x, but it's ATan2(x, y) on SpatiaLite < 5.0.0.
# Cast integers to float to avoid inconsistent/buggy behavior if the
# arguments are mixed between integer and float or decimal.
# https://www.gaia-gis.it/fossil/libspatialite/tktview?name=0f72cca3a2
clone = self.copy()
clone.set_source_expressions([
Cast(expression, FloatField()) if isinstance(expression.output_field, IntegerField)
else expression for expression in self.get_source_expressions()[::-1]
])
return clone.as_sql(compiler, connection, **extra_context)
class Ceil(Transform):
function = 'CEILING'
lookup_name = 'ceil'
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='CEIL', **extra_context)
class Cos(NumericOutputFieldMixin, Transform):
function = 'COS'
lookup_name = 'cos'
class Cot(NumericOutputFieldMixin, Transform):
function = 'COT'
lookup_name = 'cot'
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, template='(1 / TAN(%(expressions)s))', **extra_context)
class Degrees(NumericOutputFieldMixin, Transform):
function = 'DEGREES'
lookup_name = 'degrees'
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection,
template='((%%(expressions)s) * 180 / %s)' % math.pi,
**extra_context
)
class Exp(NumericOutputFieldMixin, Transform):
function = 'EXP'
lookup_name = 'exp'
class Floor(Transform):
function = 'FLOOR'
lookup_name = 'floor'
class Ln(NumericOutputFieldMixin, Transform):
function = 'LN'
lookup_name = 'ln'
class Log(FixDecimalInputMixin, NumericOutputFieldMixin, Func):
function = 'LOG'
arity = 2
def as_sqlite(self, compiler, connection, **extra_context):
if not getattr(connection.ops, 'spatialite', False):
return self.as_sql(compiler, connection)
# This function is usually Log(b, x) returning the logarithm of x to
# the base b, but on SpatiaLite it's Log(x, b).
clone = self.copy()
clone.set_source_expressions(self.get_source_expressions()[::-1])
return clone.as_sql(compiler, connection, **extra_context)
class Mod(FixDecimalInputMixin, NumericOutputFieldMixin, Func):
function = 'MOD'
arity = 2
class Pi(NumericOutputFieldMixin, Func):
function = 'PI'
arity = 0
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, template=str(math.pi), **extra_context)
class Power(NumericOutputFieldMixin, Func):
function = 'POWER'
arity = 2
class Radians(NumericOutputFieldMixin, Transform):
function = 'RADIANS'
lookup_name = 'radians'
def as_oracle(self, compiler, connection, **extra_context):
return super().as_sql(
compiler, connection,
template='((%%(expressions)s) * %s / 180)' % math.pi,
**extra_context
)
class Round(Transform):
function = 'ROUND'
lookup_name = 'round'
class Sign(Transform):
function = 'SIGN'
lookup_name = 'sign'
class Sin(NumericOutputFieldMixin, Transform):
function = 'SIN'
lookup_name = 'sin'
class Sqrt(NumericOutputFieldMixin, Transform):
function = 'SQRT'
lookup_name = 'sqrt'
class Tan(NumericOutputFieldMixin, Transform):
function = 'TAN'
lookup_name = 'tan'
|
1d8cf2f53c53d29ae5a02aaf63d43c89c853e06727f63d3d05d413b12d2b801b | 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 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 = copy.lhs.output_field
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)
)
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 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(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
def __init__(self, expression, output_field=None, tzinfo=None, is_dst=None, **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)
if isinstance(self.output_field, DateTimeField):
tzname = self.get_tzname()
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)
elif isinstance(self.output_field, TimeField):
sql = connection.ops.time_trunc_sql(self.kind, inner_sql)
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.
assert isinstance(field, (DateField, TimeField)), (
"%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):
def __init__(self, expression, kind, output_field=None, tzinfo=None, is_dst=None, **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 = timezone.get_current_timezone_name() if settings.USE_TZ else None
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 = timezone.get_current_timezone_name() if settings.USE_TZ else None
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)
|
2ec9cb1c716b22fe7f85910137b89340c16e6bf810946e270ce441f039d5792c | import sys
from django.db.models.fields import DecimalField, FloatField, IntegerField
from django.db.models.functions import Cast
class FixDecimalInputMixin:
def as_postgresql(self, compiler, connection, **extra_context):
# Cast FloatField to DecimalField as PostgreSQL doesn't support the
# following function signatures:
# - LOG(double, double)
# - MOD(double, double)
output_field = DecimalField(decimal_places=sys.float_info.dig, max_digits=1000)
clone = self.copy()
clone.set_source_expressions([
Cast(expression, output_field) if isinstance(expression.output_field, FloatField)
else expression for expression in self.get_source_expressions()
])
return clone.as_sql(compiler, connection, **extra_context)
class FixDurationInputMixin:
def as_mysql(self, compiler, connection, **extra_context):
sql, params = super().as_sql(compiler, connection, **extra_context)
if self.output_field.get_internal_type() == 'DurationField':
sql = 'CAST(%s AS SIGNED)' % sql
return sql, params
def as_oracle(self, compiler, connection, **extra_context):
if self.output_field.get_internal_type() == 'DurationField':
expression = self.get_source_expressions()[0]
options = self._get_repr_options()
from django.db.backends.oracle.functions import IntervalToSeconds, SecondsToInterval
return compiler.compile(
SecondsToInterval(self.__class__(IntervalToSeconds(expression), **options))
)
return super().as_sql(compiler, connection, **extra_context)
class NumericOutputFieldMixin:
def _resolve_output_field(self):
source_fields = self.get_source_fields()
if any(isinstance(s, DecimalField) for s in source_fields):
return DecimalField()
if any(isinstance(s, IntegerField) for s in source_fields):
return FloatField()
return super()._resolve_output_field() if source_fields else FloatField()
|
c650a22763e510c9dadf8fd95ed801f95a9bb533070f5a0fa3db91bdb67e40b8 | """
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 difflib
import functools
import inspect
import sys
import warnings
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 (
EmptyResultSet, 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, F, OuterRef, Ref, SimpleCol,
)
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, ORDER_PATTERN, 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.deprecation import RemovedInDjango40Warning
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')
)
def _get_col(target, field, alias, simple_col):
if simple_col:
return SimpleCol(target, field)
return target.get_col(alias, field)
class RawQuery:
"""A single raw SQL query."""
def __init__(self, sql, using, params=None):
self.params = params or ()
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):
return dict if isinstance(self.params, Mapping) else tuple
def __str__(self):
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()}
else:
raise RuntimeError("Unexpected params type: %s" % params_type)
self.cursor = connection.cursor()
self.cursor.execute(self.sql, params)
class Query(BaseExpression):
"""A single SQL query."""
alias_prefix = 'T'
subq_aliases = frozenset([alias_prefix])
compiler = 'SQLCompiler'
def __init__(self, model, where=WhereNode):
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 = {}
# 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.
self.external_aliases = set()
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 = where()
self.where_class = where
# 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_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_query = False
self.explain_format = None
self.explain_options = {}
@property
def output_field(self):
if len(self.select) == 1:
return self.select[0].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):
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)
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 None:
obj.annotation_select_mask = None
else:
obj.annotation_select_mask = self.annotation_select_mask.copy()
# _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 None:
obj.extra_select_mask = None
else:
obj.extra_select_mask = self.extra_select_mask.copy()
if self._extra_select_cache is None:
obj._extra_select_cache = None
else:
obj._extra_select_cache = self._extra_select_cache.copy()
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 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 == 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 {}
has_limit = self.low_mark != 0 or self.high_mark is not None
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 has_limit or existing_annotations or
self.distinct or self.combinator):
from django.db.models.sql.subqueries import AggregateQuery
outer_query = AggregateQuery(self.model)
inner_query = self.clone()
inner_query.select_for_update = False
inner_query.select_related = False
inner_query.set_annotation_mask(self.annotation_select)
if not has_limit and not self.distinct_fields:
# 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(True)
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()),)
try:
outer_query.add_subquery(inner_query, using)
except EmptyResultSet:
return {
alias: None
for alias in outer_query.annotation_select
}
else:
outer_query = self
self.select = ()
self.default_cols = False
self.extra = {}
outer_query.clear_ordering(True)
outer_query.clear_limits()
outer_query.select_for_update = False
outer_query.select_related = False
compiler = outer_query.get_compiler(using)
result = compiler.execute_sql(SINGLE)
if result is None:
result = [None] * len(outer_query.annotation_select)
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)
number = obj.get_aggregation(using, ['__count'])['__count']
if number is None:
number = 0
return number
def has_filters(self):
return self.where
def has_results(self, using):
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)
q.set_group_by()
q.clear_select_clause()
q.clear_ordering(True)
q.set_limits(high=1)
compiler = q.get_compiler(using=using)
return compiler.has_results()
def explain(self, using, format=None, **options):
q = self.clone()
q.explain_query = True
q.explain_format = format
q.explain_options = 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.
"""
assert self.model == rhs.model, \
"Cannot combine queries on two different base models."
assert self.can_filter(), \
"Cannot combine queries once a slice has been taken."
assert self.distinct == rhs.distinct, \
"Cannot combine a unique query with a non-unique query."
assert self.distinct_fields == rhs.distinct_fields, \
"Cannot combine queries with different distinct fields."
# 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)
# Base table must be present in the query - this is the same
# table on both sides.
self.get_initial_alias()
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)
# 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.
"""
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 = {change_map.get(alias, alias)
for alias in self.external_aliases}
def bump_prefix(self, outer_query):
"""
Change the alias prefix to the next letter in the alphabet in a way
that the outer 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.
"""
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 != outer_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])
outer_query.subq_aliases = outer_query.subq_aliases.union(self.subq_aliases)
self.change_aliases({
alias: '%s%d' % (self.alias_prefix, pos)
for pos, alias in enumerate(self.alias_map)
})
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(BaseTable(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, reuse_with_filtered_relation=False):
"""
Return an alias for the 'join', either reusing an existing alias for
that join or creating a new one. 'join' is either a
sql.datastructures.BaseTable or Join.
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.
The 'reuse_with_filtered_relation' parameter is used when computing
FilteredRelation instances.
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.
"""
if reuse_with_filtered_relation and reuse:
reuse_aliases = [
a for a, j in self.alias_map.items()
if a in reuse and j.equals(join, with_filtered_relation=False)
]
else:
reuse_aliases = [
a for a, j in self.alias_map.items()
if (reuse is None or a in reuse) and j == 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):
"""Add a single annotation expression to the Query."""
annotation = annotation.resolve_expression(self, allow_joins=True, reuse=None,
summarize=is_summary)
self.append_annotation_mask([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
# It's safe to drop ordering if the queryset isn't using slicing,
# distinct(*fields) or select_for_update().
if (self.low_mark == 0 and self.high_mark is None and
not self.distinct_fields and
not self.select_for_update):
clone.clear_ordering(True)
clone.where.resolve_expression(query, *args, **kwargs)
for key, value in clone.annotations.items():
resolved = value.resolve_expression(query, *args, **kwargs)
if hasattr(resolved, 'external_aliases'):
resolved.external_aliases.update(clone.alias_map)
clone.annotations[key] = resolved
# Outer query's aliases are considered external.
clone.external_aliases.update(
alias for alias, table in query.alias_map.items()
if (
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 as_sql(self, compiler, connection):
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, simple_col):
if hasattr(value, 'resolve_expression'):
kwargs = {'reuse': can_reuse, 'allow_joins': allow_joins}
if isinstance(value, F):
kwargs['simple_col'] = simple_col
value = value.resolve_expression(self, **kwargs)
elif isinstance(value, (list, tuple)):
# The items of the iterable may be expressions and therefore need
# to be resolved independently.
for sub_value in value:
if hasattr(sub_value, 'resolve_expression'):
if isinstance(sub_value, F):
sub_value.resolve_expression(
self, reuse=can_reuse, allow_joins=allow_joins,
simple_col=simple_col,
)
else:
sub_value.resolve_expression(self, reuse=can_reuse, allow_joins=allow_joins)
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 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 (connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls and
lookup_name == 'exact' and lookup.rhs == ''):
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,
reuse_with_filtered_relation=False, simple_col=False):
"""
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.
If 'reuse_with_filtered_relation' is True, then only joins in can_reuse
will be reused.
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")
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 not getattr(reffed_expression, 'filterable', True):
raise NotSupportedError(
reffed_expression.__class__.__name__ + ' is disallowed in '
'the filter clause.'
)
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, simple_col)
used_joins = {k for k, v in self.alias_refcount.items() if v > pre_joins.get(k, 0)}
clause = self.where_class()
if reffed_expression:
condition = self.build_lookup(lookups, reffed_expression, value)
clause.add(condition, AND)
return clause, []
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,
reuse_with_filtered_relation=reuse_with_filtered_relation,
)
# 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 = _get_col(targets[0], join_info.final_field, alias, simple_col)
else:
col = MultiColSource(alias, targets, join_info.targets, join_info.final_field)
else:
col = _get_col(targets[0], join_info.final_field, alias, simple_col)
condition = self.build_lookup(lookups, col, value)
lookup_type = condition.lookup_name
clause.add(condition, 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' and (
self.is_nullable(targets[0]) or
self.alias_map[join_list[-1]].join_type == LOUTER)):
# 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).
lookup_class = targets[0].get_lookup('isnull')
col = _get_col(targets[0], join_info.targets[0], alias, simple_col)
clause.add(lookup_class(col, False), AND)
return clause, used_joins if not require_outer else ()
def add_filter(self, filter_clause):
self.add_q(Q(**{filter_clause[0]: filter_clause[1]}))
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, q_object):
return self._add_q(q_object, used_aliases=set(), allow_joins=False, simple_col=True)[0]
def _add_q(self, q_object, used_aliases, branch_negated=False,
current_negated=False, allow_joins=True, split_subq=True,
simple_col=False):
"""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 = self.where_class(connector=connector,
negated=q_object.negated)
joinpromoter = JoinPromoter(q_object.connector, len(q_object.children), current_negated)
for child in q_object.children:
if isinstance(child, Node):
child_clause, needed_inner = self._add_q(
child, used_aliases, branch_negated,
current_negated, allow_joins, split_subq, simple_col)
joinpromoter.add_votes(needed_inner)
else:
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, simple_col=simple_col,
)
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 = self.where_class(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,
reuse_with_filtered_relation=True,
)
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))
for lookup in chain((filtered_relation.relation_name,), lookups):
lookup_parts, field_parts, _ = self.solve_lookup_type(lookup)
shift = 2 if not lookup_parts else 1
if len(field_parts) > (shift + len(lookup_parts)):
raise ValueError(
"FilteredRelation's condition doesn't support nested "
"relations (got %r)." % lookup
)
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]
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, 'get_path_info'):
pathinfos = field.get_path_info(filtered_relation)
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,
reuse_with_filtered_relation=False):
"""
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().
The 'reuse_with_filtered_relation' can be used to force 'can_reuse'
parameter and force the relation on the given connections.
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):
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 = Join(
opts.db_table, alias, table_alias, INNER, join.join_field,
nullable, filtered_relation=filtered_relation,
)
reuse = can_reuse if join.m2m or reuse_with_filtered_relation else None
alias = self.join(
connection, reuse=reuse,
reuse_with_filtered_relation=reuse_with_filtered_relation,
)
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
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False, simple_col=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
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.
return Ref(name, self.annotation_select[name])
else:
return self.annotations[name]
else:
field_list = name.split(LOOKUP_SEP)
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.
join_info.transform_function(targets[0], final_alias)
if reuse is not None:
reuse.update(join_list)
col = _get_col(targets[0], join_info.targets[0], join_list[-1], simple_col)
return col
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 (pk IN (SELECT parent_id FROM thetable
WHERE name = 'foo' AND parent_id IS NOT NULL))
It might be worth it to consider using WHERE NOT EXISTS as that has
saner null handling, and is easier for the backend's optimizer to
handle.
"""
filter_lhs, filter_rhs = filter_expr
if isinstance(filter_rhs, F):
filter_expr = (filter_lhs, OuterRef(filter_rhs.name))
# Generate the inner query.
query = Query(self.model)
query._filtered_relations = self._filtered_relations
query.add_filter(filter_expr)
query.clear_ordering(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)
# Add extra check to make sure the selected field will not be null
# since we are adding an IN <subquery> clause. This prevents the
# database from tripping over IN (...,NULL,...) selects and returning
# nothing
col = query.select[0]
select_field = col.target
alias = col.alias
if self.is_nullable(select_field):
lookup_class = select_field.get_lookup('isnull')
lookup = lookup_class(select_field.get_col(alias), False)
query.where.add(lookup, AND)
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.add(alias)
condition, needed_inner = self.build_filter(
('%s__in' % trimmed_prefix, query),
current_negated=True, branch_negated=True, can_reuse=can_reuse)
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)
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
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.low_mark and self.high_mark is None
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 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
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 not hasattr(item, 'resolve_expression') and not ORDER_PATTERN.match(item):
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_empty):
"""
Remove any ordering settings. If 'force_empty' is True, there will be
no ordering in the resulting query (not even the model's default).
"""
self.order_by = ()
self.extra_order_by = ()
if force_empty:
self.default_ordering = False
def set_group_by(self):
"""
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.
"""
group_by = list(self.select)
if self.annotation_select:
for alias, annotation in self.annotation_select.items():
try:
inspect.getcallargs(annotation.get_group_by_cols, alias=alias)
except TypeError:
annotation_class = annotation.__class__
msg = (
'`alias=None` must be added to the signature of '
'%s.%s.get_group_by_cols().'
) % (annotation_class.__module__, annotation_class.__qualname__)
warnings.warn(msg, category=RemovedInDjango40Warning)
group_by_cols = annotation.get_group_by_cols()
else:
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.
self.deferred_loading = existing.difference(field_names), False
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 self.group_by is True:
self.add_fields((f.attname for f in self.model._meta.concrete_fields), False)
self.set_group_by()
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)
else:
field_names = [f.attname for f in self.model._meta.concrete_fields]
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(
self.where_class, 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 instead of a BaseTable 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] = BaseTable(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 (
connections[DEFAULT_DB_ALIAS].features.interprets_empty_strings_as_nulls and
field.empty_strings_allowed
) or field.null
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 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
|
8346b2e8d5b645a0ceb5fff3e4e0271e0f53573902b6e9cdc951d91bb9b86f3b | import collections
import re
import warnings
from itertools import chain
from django.core.exceptions import EmptyResultSet, FieldError
from django.db.models.constants import LOOKUP_SEP
from django.db.models.expressions import OrderBy, Random, RawSQL, Ref, Value
from django.db.models.functions import Cast
from django.db.models.query_utils import QueryWrapper, 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.db.utils import DatabaseError, NotSupportedError
from django.utils.deprecation import RemovedInDjango31Warning
from django.utils.hashable import make_hashable
FORCE = object()
class SQLCompiler:
def __init__(self, query, connection, using):
self.query = query
self.connection = connection
self.using = using
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
# Multiline ordering SQL clause may appear from RawSQL.
self.ordering_parts = re.compile(r'^(.*)\s(ASC|DESC)(.*)', re.MULTILINE | re.DOTALL)
self._meta_ordering = None
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.
for expr, _, _ in select:
cols = expr.get_group_by_cols()
for col in cols:
expressions.append(col)
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 expr.contains_aggregate and not is_ref:
expressions.extend(expr.get_source_expressions())
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)
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 expr.target.model._meta.managed
}
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, select_format=True)
except EmptyResultSet:
# Select a predicate that's always False.
sql, params = '0', ()
ret.append((col, (sql, params), alias))
return ret, klass_info, annotations
def get_order_by(self):
"""
Return a list of 2-tuples of 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).
"""
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:
asc, desc = ORDER_DIR['ASC']
else:
asc, desc = ORDER_DIR['DESC']
order_by = []
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()
order_by.append((field, False))
continue
if field == '?': # random
order_by.append((OrderBy(Random()), False))
continue
col, order = get_order_dir(field, asc)
descending = order == 'DESC'
if col in self.query.annotation_select:
# Reference to expression in SELECT clause
order_by.append((
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.
expr = self.query.annotations[col]
if isinstance(expr, Value):
# output_field must be resolved for constants.
expr = Cast(expr, expr.output_field)
order_by.append((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)
order_by.append((
OrderBy(
RawSQL('%s.%s' % (self.quote_name_unless_alias(table), col), []),
descending=descending
), False))
continue
if not self.query.extra or col not in self.query.extra:
# 'col' is of the form 'field' or 'field1__field2' or
# '-field1__field2__field', etc.
order_by.extend(self.find_ordering_name(
field, self.query.get_meta(), default_order=asc))
else:
if col not in self.query.extra_select:
order_by.append((
OrderBy(RawSQL(*self.query.extra[col]), descending=descending),
False))
else:
order_by.append((
OrderBy(Ref(col, RawSQL(*self.query.extra[col])), descending=descending),
True))
result = []
seen = set()
for expr, is_ref in order_by:
resolved = expr.resolve_expression(self.query, allow_joins=True, reuse=None)
if self.query.combinator:
src = resolved.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:
continue
if src == sel_expr:
resolved.set_source_expressions([RawSQL('%d' % (idx + 1), ())])
break
else:
raise DatabaseError('ORDER BY term does not match any column in the result set.')
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).group(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).group(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 (
name in self.query.external_aliases 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, select_format=False):
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)
if select_format is FORCE or (select_format and not self.query.subquery):
return node.output_field.select_format(self, sql, params)
return sql, params
def get_combinator_sql(self, combinator, all):
features = self.connection.features
compilers = [
query.get_compiler(self.using, self.connection)
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 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 features.supports_slicing_ordering_in_compound else '{}'
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()
where, w_params = self.compile(self.where) if self.where is not None else ("", [])
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, '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
# If it's a NOWAIT/SKIP LOCKED/OF 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.')
for_update_part = self.connection.ops.for_update_sql(
nowait=nowait,
skip_locked=skip_locked,
of=self.get_select_for_update_of_arguments(),
)
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:
# When the deprecation ends, replace with:
# order_by = None
warnings.warn(
"%s QuerySet won't use Meta.ordering in Django 3.1. "
"Add .order_by(%s) to retain the current query." % (
self.query.model.__name__,
', '.join(repr(f) for f in self._meta_ordering),
),
RemovedInDjango31Warning,
stacklevel=4,
)
if having:
result.append('HAVING %s' % having)
params.extend(h_params)
if self.query.explain_query:
result.insert(0, self.connection.ops.explain_query_prefix(
self.query.explain_format,
**self.query.explain_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(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 the attribute name
# of the field is specified.
if field.is_relation and opts.ordering and getattr(field, 'attname', None) != name:
# 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:
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)
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
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(obj, from_obj):
setattr(from_obj, name, obj)
klass_info = {
'model': model,
'field': f,
'reverse': True,
'local_setter': local_setter,
'remote_setter': remote_setter,
'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_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 klass_info.get('related_klass_infos', [])
)
result = []
invalid_names = []
for name in self.query.select_for_update_of:
parts = [] if name == 'self' else name.split(LOOKUP_SEP)
klass_info = self.klass_info
for part in parts:
for related_klass_info in klass_info.get('related_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
select_index = klass_info['select_fields'][0]
col = self.select[select_index][0]
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."
"""
# This is always executed on a query clone, so we can modify self.query
self.query.add_extra({'a': 1}, None, None, None, None, None)
self.query.set_extra_mask(['a'])
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:
try:
# 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)
finally:
# done with the cursor
cursor.close()
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(
QueryWrapper('%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.
for row in result[0]:
if not isinstance(row, str):
yield ' '.join(str(c) for c in row)
else:
yield row
class SQLInsertCompiler(SQLCompiler):
return_id = False
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(ignore_conflicts=self.query.ignore_conflicts)
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.return_id and self.connection.features.has_bulk_insert)
placeholder_rows, param_rows = self.assemble_as_sql(fields, value_rows)
ignore_conflicts_suffix_sql = self.connection.ops.ignore_conflicts_suffix_sql(
ignore_conflicts=self.query.ignore_conflicts
)
if self.return_id 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 ignore_conflicts_suffix_sql:
result.append(ignore_conflicts_suffix_sql)
col = "%s.%s" % (qn(opts.db_table), qn(opts.pk.column))
r_fmt, r_params = self.connection.ops.return_insert_id()
# Skip empty r_fmt to allow subclasses to customize behavior for
# 3rd party backends. Refs #19096.
if r_fmt:
result.append(r_fmt % col)
params += [r_params]
return [(" ".join(result), tuple(chain.from_iterable(params)))]
if can_bulk:
result.append(self.connection.ops.bulk_insert_sql(fields, placeholder_rows))
if ignore_conflicts_suffix_sql:
result.append(ignore_conflicts_suffix_sql)
return [(" ".join(result), tuple(p for ps in param_rows for p in ps))]
else:
if ignore_conflicts_suffix_sql:
result.append(ignore_conflicts_suffix_sql)
return [
(" ".join(result + ["VALUES (%s)" % ", ".join(p)]), vals)
for p, vals in zip(placeholder_rows, param_rows)
]
def execute_sql(self, return_id=False):
assert not (
return_id and len(self.query.objs) != 1 and
not self.connection.features.can_return_rows_from_bulk_insert
)
self.return_id = return_id
with self.connection.cursor() as cursor:
for sql, params in self.as_sql():
cursor.execute(sql, params)
if not return_id:
return
if self.connection.features.can_return_rows_from_bulk_insert and len(self.query.objs) > 1:
return self.connection.ops.fetch_returned_insert_ids(cursor)
if self.connection.features.can_return_columns_from_insert:
assert len(self.query.objs) == 1
return self.connection.ops.fetch_returned_insert_id(cursor)
return self.connection.ops.last_insert_id(
cursor, self.query.get_meta().db_table, self.query.get_meta().pk.column
)
class SQLDeleteCompiler(SQLCompiler):
def as_sql(self):
"""
Create the SQL for this query. Return the SQL string and list of
parameters.
"""
assert len([t for t in self.query.alias_map if self.query.alias_refcount[t] > 0]) == 1, \
"Can only delete from one table at a time."
qn = self.quote_name_unless_alias
result = ['DELETE FROM %s' % qn(self.query.base_table)]
where, params = self.compile(self.query.where)
if where:
result.append('WHERE %s' % where)
return ' '.join(result), tuple(params)
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(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.where = self.query.where_class()
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, select_format=FORCE)
sql.append(ann_sql)
params.extend(ann_params)
self.col_count = len(self.query.annotation_select)
sql = ', '.join(sql)
params = tuple(params)
sql = 'SELECT %s FROM (%s) subquery' % (sql, self.query.subquery)
params = params + self.query.sub_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()
|
f7499f0b42819d084bccbe4baca398a658d66d4696a3bae5955ab08db562d8ee | """
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=[], 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
@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)
@property
def is_summary(self):
return any(child.is_summary for child in self.children)
@staticmethod
def _resolve_rhs(rhs, query, *args, **kwargs):
if hasattr(rhs, 'resolve_expression'):
rhs = rhs.resolve_expression(query, *args, **kwargs)
return rhs
@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, 'rhs'):
node.rhs = cls._resolve_rhs(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
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
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)
|
cee7adb94f401a3d4c76359832dcc4af1647d95958f5d1a9f914067425ddeae3 | from django.core.exceptions import EmptyResultSet
from django.db.models.sql.query import * # NOQA
from django.db.models.sql.query import Query
from django.db.models.sql.subqueries import * # NOQA
from django.db.models.sql.where import AND, OR
__all__ = ['Query', 'AND', 'OR', 'EmptyResultSet']
|
d485e639249aaa7bbf77701bda2ca9f7b9eb570d25ff0a452c4a2c6807cb8873 | """
Useful auxiliary data structures for query construction. Not useful outside
the SQL domain.
"""
# for backwards-compatibility in Django 1.11
from django.core.exceptions import EmptyResultSet # NOQA: F401
from django.db.models.sql.constants import INNER, LOUTER
class MultiJoin(Exception):
"""
Used by join construction code to indicate the point at which a
multi-valued join was attempted (if the caller wants to treat that
exceptionally).
"""
def __init__(self, names_pos, path_with_names):
self.level = names_pos
# The path travelled, this includes the path to the multijoin.
self.names_with_path = path_with_names
class Empty:
pass
class Join:
"""
Used by sql.Query and sql.SQLCompiler to generate JOIN clauses into the
FROM entry. For example, the SQL generated could be
LEFT OUTER JOIN "sometable" T1 ON ("othertable"."sometable_id" = "sometable"."id")
This class is primarily used in Query.alias_map. All entries in alias_map
must be Join compatible by providing the following attributes and methods:
- table_name (string)
- table_alias (possible alias for the table, can be None)
- join_type (can be None for those entries that aren't joined from
anything)
- parent_alias (which table is this join's parent, can be None similarly
to join_type)
- as_sql()
- relabeled_clone()
"""
def __init__(self, table_name, parent_alias, table_alias, join_type,
join_field, nullable, filtered_relation=None):
# Join table
self.table_name = table_name
self.parent_alias = parent_alias
# Note: table_alias is not necessarily known at instantiation time.
self.table_alias = table_alias
# LOUTER or INNER
self.join_type = join_type
# A list of 2-tuples to use in the ON clause of the JOIN.
# Each 2-tuple will create one join condition in the ON clause.
self.join_cols = join_field.get_joining_columns()
# Along which field (or ForeignObjectRel in the reverse join case)
self.join_field = join_field
# Is this join nullabled?
self.nullable = nullable
self.filtered_relation = filtered_relation
def as_sql(self, compiler, connection):
"""
Generate the full
LEFT OUTER JOIN sometable ON sometable.somecol = othertable.othercol, params
clause for this join.
"""
join_conditions = []
params = []
qn = compiler.quote_name_unless_alias
qn2 = connection.ops.quote_name
# Add a join condition for each pair of joining columns.
for lhs_col, rhs_col in self.join_cols:
join_conditions.append('%s.%s = %s.%s' % (
qn(self.parent_alias),
qn2(lhs_col),
qn(self.table_alias),
qn2(rhs_col),
))
# Add a single condition inside parentheses for whatever
# get_extra_restriction() returns.
extra_cond = self.join_field.get_extra_restriction(
compiler.query.where_class, self.table_alias, self.parent_alias)
if extra_cond:
extra_sql, extra_params = compiler.compile(extra_cond)
join_conditions.append('(%s)' % extra_sql)
params.extend(extra_params)
if self.filtered_relation:
extra_sql, extra_params = compiler.compile(self.filtered_relation)
if extra_sql:
join_conditions.append('(%s)' % extra_sql)
params.extend(extra_params)
if not join_conditions:
# This might be a rel on the other end of an actual declared field.
declared_field = getattr(self.join_field, 'field', self.join_field)
raise ValueError(
"Join generated an empty ON clause. %s did not yield either "
"joining columns or extra restrictions." % declared_field.__class__
)
on_clause_sql = ' AND '.join(join_conditions)
alias_str = '' if self.table_alias == self.table_name else (' %s' % self.table_alias)
sql = '%s %s%s ON (%s)' % (self.join_type, qn(self.table_name), alias_str, on_clause_sql)
return sql, params
def relabeled_clone(self, change_map):
new_parent_alias = change_map.get(self.parent_alias, self.parent_alias)
new_table_alias = change_map.get(self.table_alias, self.table_alias)
if self.filtered_relation is not None:
filtered_relation = self.filtered_relation.clone()
filtered_relation.path = [change_map.get(p, p) for p in self.filtered_relation.path]
else:
filtered_relation = None
return self.__class__(
self.table_name, new_parent_alias, new_table_alias, self.join_type,
self.join_field, self.nullable, filtered_relation=filtered_relation,
)
def equals(self, other, with_filtered_relation):
return (
isinstance(other, self.__class__) and
self.table_name == other.table_name and
self.parent_alias == other.parent_alias and
self.join_field == other.join_field and
(not with_filtered_relation or self.filtered_relation == other.filtered_relation)
)
def __eq__(self, other):
return self.equals(other, with_filtered_relation=True)
def demote(self):
new = self.relabeled_clone({})
new.join_type = INNER
return new
def promote(self):
new = self.relabeled_clone({})
new.join_type = LOUTER
return new
class BaseTable:
"""
The BaseTable class is used for base table references in FROM clause. For
example, the SQL "foo" in
SELECT * FROM "foo" WHERE somecond
could be generated by this class.
"""
join_type = None
parent_alias = None
filtered_relation = None
def __init__(self, table_name, alias):
self.table_name = table_name
self.table_alias = alias
def as_sql(self, compiler, connection):
alias_str = '' if self.table_alias == self.table_name else (' %s' % self.table_alias)
base_sql = compiler.quote_name_unless_alias(self.table_name)
return base_sql + alias_str, []
def relabeled_clone(self, change_map):
return self.__class__(self.table_name, change_map.get(self.table_alias, self.table_alias))
def equals(self, other, with_filtered_relation):
return (
isinstance(self, other.__class__) and
self.table_name == other.table_name and
self.table_alias == other.table_alias
)
|
986bf4b33615fcbdcc43ad9dfec001aa950eb10537bd0660c42502915a2fe0ce | """
Query subclasses which provide extra functionality beyond simple data retrieval.
"""
from django.core.exceptions import FieldError
from django.db import connections
from django.db.models.query_utils import Q
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)
return cursor.rowcount if cursor else 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.where = self.where_class()
self.add_q(Q(
**{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
def delete_qs(self, query, using):
"""
Delete the queryset in one SQL query (if possible). For simple queries
this is done by copying the query.query.where to self.query, for
complex queries by using subquery.
"""
innerq = query.query
# Make sure the inner query has at least one table in use.
innerq.get_initial_alias()
# The same for our new query.
self.get_initial_alias()
innerq_used_tables = tuple([t for t in innerq.alias_map if innerq.alias_refcount[t]])
if not innerq_used_tables or innerq_used_tables == tuple(self.alias_map):
# There is only the base table in use in the query.
self.where = innerq.where
else:
pk = query.model._meta.pk
if not connections[using].features.update_can_self_select:
# We can't do the delete using subquery.
values = list(query.values_list('pk', flat=True))
if not values:
return 0
return self.delete_batch(values, using)
else:
innerq.clear_select_clause()
innerq.select = [
pk.get_col(self.get_initial_alias())
]
values = innerq
self.where = self.where_class()
self.add_q(Q(pk__in=values))
cursor = self.get_compiler(using).execute_sql(CURSOR)
return cursor.rowcount if cursor else 0
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.where = self.where_class()
self.add_q(Q(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, ignore_conflicts=False, **kwargs):
super().__init__(*args, **kwargs)
self.fields = []
self.objs = []
self.ignore_conflicts = ignore_conflicts
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 add_subquery(self, query, using):
query.subquery = True
self.subquery, self.sub_params = query.get_compiler(using).as_sql(with_col_aliases=True)
|
26361877867205b50300895d3554442a4715503258df4d5168cd269a80aad5ce | from django.db.backends.base.features import BaseDatabaseFeatures
from django.db.utils import InterfaceError
class DatabaseFeatures(BaseDatabaseFeatures):
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
can_introspect_autofield = True
supports_subqueries_in_group_by = False
supports_transactions = True
supports_timezones = False
has_native_duration_field = True
can_defer_constraint_checks = True
supports_partially_nullable_unique_constraints = False
truncates_names = True
supports_tablespaces = True
supports_sequence_reset = False
can_introspect_materialized_views = True
can_introspect_time_field = False
atomic_transactions = False
supports_combined_alters = 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
has_case_insensitive_like = 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
|
821246dc3e7655a80e6599d72188c22bfdc82256e1b77ecaac9b8e74c7308500 | from collections import namedtuple
import cx_Oracle
from django.db import models
from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo as BaseFieldInfo, TableInfo,
)
FieldInfo = namedtuple('FieldInfo', BaseFieldInfo._fields + ('is_autofield',))
class DatabaseIntrospection(BaseDatabaseIntrospection):
# Maps type objects to Django Field types.
data_types_reverse = {
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',
}
cache_bust_counter = 1
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 precision == 1:
return 'BooleanField'
elif description.is_autofield:
return 'AutoField'
else:
return 'IntegerField'
elif scale == -127:
return 'FloatField'
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
column_name,
data_default,
CASE
WHEN char_used IS NULL THEN data_length
ELSE char_length
END as internal_size,
CASE
WHEN identity_column = 'YES' THEN 1
ELSE 0
END as is_autofield
FROM user_tab_cols
WHERE table_name = UPPER(%s)""", [table_name])
field_map = {
column: (internal_size, default if default != 'NULL' else None, is_autofield)
for column, default, internal_size, is_autofield 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, is_autofield = 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, is_autofield,
))
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 relationships to 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_key_columns(self, cursor, table_name):
cursor.execute("""
SELECT ccol.column_name, rcol.table_name AS referenced_table, rcol.column_name AS referenced_column
FROM user_constraints c
JOIN user_cons_columns ccol
ON ccol.constraint_name = c.constraint_name
JOIN user_cons_columns rcol
ON rcol.constraint_name = c.r_constraint_name
WHERE c.table_name = %s AND c.constraint_type = 'R'""", [table_name.upper()])
return [
tuple(self.identifier_converter(cell) for cell in row)
for row 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),
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
""", [table_name])
for constraint, type_, columns, orders in cursor.fetchall():
constraint = self.identifier_converter(constraint)
constraints[constraint] = {
'primary_key': False,
'unique': False,
'foreign_key': None,
'check': False,
'index': True,
'type': 'idx' if type_ == 'normal' else type_,
'columns': columns.split(','),
'orders': orders.split(','),
}
return constraints
|
0157e93b315d3ac37c1be78aee650ef0f93af8a61445a1c49434786b22b90d19 | """
Oracle database backend for Django.
Requires cx_Oracle: https://oracle.github.io/python-cx_Oracle/
"""
import datetime
import decimal
import os
import platform
from contextlib import contextmanager
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import utils
from django.db.backends.base.base import BaseDatabaseWrapper
from django.utils.encoding import force_bytes, force_str
from django.utils.functional import cached_property
def _setup_environment(environ):
# Cygwin requires some special voodoo to set the environment variables
# properly so that Oracle will see them.
if platform.system().upper().startswith('CYGWIN'):
try:
import ctypes
except ImportError as e:
raise ImproperlyConfigured("Error loading ctypes: %s; "
"the Oracle backend requires ctypes to "
"operate correctly under Cygwin." % e)
kernel32 = ctypes.CDLL('kernel32')
for name, value in environ:
kernel32.SetEnvironmentVariableA(name, value)
else:
os.environ.update(environ)
_setup_environment([
# Oracle takes client-side character set encoding from the environment.
('NLS_LANG', '.AL32UTF8'),
# This prevents unicode from getting mangled by getting encoded into the
# potentially non-unicode database character set.
('ORA_NCHAR_LITERAL_REPLACE', 'TRUE'),
])
try:
import cx_Oracle as Database
except ImportError as e:
raise ImproperlyConfigured("Error loading cx_Oracle module: %s" % e)
# Some of these import cx_Oracle, so import them after checking if it's installed.
from .client import DatabaseClient # NOQA isort:skip
from .creation import DatabaseCreation # NOQA isort:skip
from .features import DatabaseFeatures # NOQA isort:skip
from .introspection import DatabaseIntrospection # NOQA isort:skip
from .operations import DatabaseOperations # NOQA isort:skip
from .schema import DatabaseSchemaEditor # NOQA isort:skip
from .utils import Oracle_datetime # NOQA isort:skip
from .validation import DatabaseValidation # NOQA isort:skip
@contextmanager
def wrap_oracle_errors():
try:
yield
except Database.DatabaseError as e:
# cx_Oracle raises a cx_Oracle.DatabaseError exception with the
# following attributes and values:
# code = 2091
# message = 'ORA-02091: transaction rolled back
# 'ORA-02291: integrity constraint (TEST_DJANGOTEST.SYS
# _C00102056) violated - parent key not found'
# Convert that case to Django's IntegrityError exception.
x = e.args[0]
if hasattr(x, 'code') and hasattr(x, 'message') and x.code == 2091 and 'ORA-02291' in x.message:
raise utils.IntegrityError(*tuple(e.args))
raise
class _UninitializedOperatorsDescriptor:
def __get__(self, instance, cls=None):
# If connection.operators is looked up before a connection has been
# created, transparently initialize connection.operators to avert an
# AttributeError.
if instance is None:
raise AttributeError("operators not available as class attribute")
# Creating a cursor will initialize the operators.
instance.cursor().close()
return instance.__dict__['operators']
class DatabaseWrapper(BaseDatabaseWrapper):
vendor = 'oracle'
display_name = 'Oracle'
# This dictionary maps Field objects to their associated Oracle 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.
#
# Any format strings starting with "qn_" are quoted before being used in the
# output (the "qn_" prefix is stripped before the lookup is performed.
data_types = {
'AutoField': 'NUMBER(11) GENERATED BY DEFAULT ON NULL AS IDENTITY',
'BigAutoField': 'NUMBER(19) GENERATED BY DEFAULT ON NULL AS IDENTITY',
'BinaryField': 'BLOB',
'BooleanField': 'NUMBER(1)',
'CharField': 'NVARCHAR2(%(max_length)s)',
'DateField': 'DATE',
'DateTimeField': 'TIMESTAMP',
'DecimalField': 'NUMBER(%(max_digits)s, %(decimal_places)s)',
'DurationField': 'INTERVAL DAY(9) TO SECOND(6)',
'FileField': 'NVARCHAR2(%(max_length)s)',
'FilePathField': 'NVARCHAR2(%(max_length)s)',
'FloatField': 'DOUBLE PRECISION',
'IntegerField': 'NUMBER(11)',
'BigIntegerField': 'NUMBER(19)',
'IPAddressField': 'VARCHAR2(15)',
'GenericIPAddressField': 'VARCHAR2(39)',
'NullBooleanField': 'NUMBER(1)',
'OneToOneField': 'NUMBER(11)',
'PositiveIntegerField': 'NUMBER(11)',
'PositiveSmallIntegerField': 'NUMBER(11)',
'SlugField': 'NVARCHAR2(%(max_length)s)',
'SmallIntegerField': 'NUMBER(11)',
'TextField': 'NCLOB',
'TimeField': 'TIMESTAMP',
'URLField': 'VARCHAR2(%(max_length)s)',
'UUIDField': 'VARCHAR2(32)',
}
data_type_check_constraints = {
'BooleanField': '%(qn_column)s IN (0,1)',
'NullBooleanField': '%(qn_column)s IN (0,1)',
'PositiveIntegerField': '%(qn_column)s >= 0',
'PositiveSmallIntegerField': '%(qn_column)s >= 0',
}
# Oracle doesn't support a database index on these columns.
_limited_data_types = ('clob', 'nclob', 'blob')
operators = _UninitializedOperatorsDescriptor()
_standard_operators = {
'exact': '= %s',
'iexact': '= UPPER(%s)',
'contains': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
'icontains': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
'gt': '> %s',
'gte': '>= %s',
'lt': '< %s',
'lte': '<= %s',
'startswith': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
'endswith': "LIKE TRANSLATE(%s USING NCHAR_CS) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
'istartswith': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
'iendswith': "LIKE UPPER(TRANSLATE(%s USING NCHAR_CS)) ESCAPE TRANSLATE('\\' USING NCHAR_CS)",
}
_likec_operators = {
**_standard_operators,
'contains': "LIKEC %s ESCAPE '\\'",
'icontains': "LIKEC UPPER(%s) ESCAPE '\\'",
'startswith': "LIKEC %s ESCAPE '\\'",
'endswith': "LIKEC %s ESCAPE '\\'",
'istartswith': "LIKEC UPPER(%s) ESCAPE '\\'",
'iendswith': "LIKEC UPPER(%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 the 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': "'%%' || {} || '%%'",
'icontains': "'%%' || UPPER({}) || '%%'",
'startswith': "{} || '%%'",
'istartswith': "UPPER({}) || '%%'",
'endswith': "'%%' || {}",
'iendswith': "'%%' || UPPER({})",
}
_standard_pattern_ops = {k: "LIKE TRANSLATE( " + v + " USING NCHAR_CS)"
" ESCAPE TRANSLATE('\\' USING NCHAR_CS)"
for k, v in _pattern_ops.items()}
_likec_pattern_ops = {k: "LIKEC " + v + " ESCAPE '\\'"
for k, v in _pattern_ops.items()}
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 __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
use_returning_into = self.settings_dict["OPTIONS"].get('use_returning_into', True)
self.features.can_return_columns_from_insert = use_returning_into
def _dsn(self):
settings_dict = self.settings_dict
if not settings_dict['HOST'].strip():
settings_dict['HOST'] = 'localhost'
if settings_dict['PORT']:
return Database.makedsn(settings_dict['HOST'], int(settings_dict['PORT']), settings_dict['NAME'])
return settings_dict['NAME']
def _connect_string(self):
return '%s/"%s"@%s' % (self.settings_dict['USER'], self.settings_dict['PASSWORD'], self._dsn())
def get_connection_params(self):
conn_params = self.settings_dict['OPTIONS'].copy()
if 'use_returning_into' in conn_params:
del conn_params['use_returning_into']
return conn_params
def get_new_connection(self, conn_params):
return Database.connect(
user=self.settings_dict['USER'],
password=self.settings_dict['PASSWORD'],
dsn=self._dsn(),
**conn_params,
)
def init_connection_state(self):
cursor = self.create_cursor()
# Set the territory first. The territory overrides NLS_DATE_FORMAT
# and NLS_TIMESTAMP_FORMAT to the territory default. When all of
# these are set in single statement it isn't clear what is supposed
# to happen.
cursor.execute("ALTER SESSION SET NLS_TERRITORY = 'AMERICA'")
# Set Oracle date to ANSI date format. This only needs to execute
# once when we create a new connection. We also set the Territory
# to 'AMERICA' which forces Sunday to evaluate to a '1' in
# TO_CHAR().
cursor.execute(
"ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS'"
" NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH24:MI:SS.FF'" +
(" TIME_ZONE = 'UTC'" if settings.USE_TZ else '')
)
cursor.close()
if 'operators' not in self.__dict__:
# Ticket #14149: Check whether our LIKE implementation will
# work for this connection or we need to fall back on LIKEC.
# This check is performed only once per DatabaseWrapper
# instance per thread, since subsequent connections will use
# the same settings.
cursor = self.create_cursor()
try:
cursor.execute("SELECT 1 FROM DUAL WHERE DUMMY %s"
% self._standard_operators['contains'],
['X'])
except Database.DatabaseError:
self.operators = self._likec_operators
self.pattern_ops = self._likec_pattern_ops
else:
self.operators = self._standard_operators
self.pattern_ops = self._standard_pattern_ops
cursor.close()
self.connection.stmtcachesize = 20
# Ensure all changes are preserved even when AUTOCOMMIT is False.
if not self.get_autocommit():
self.commit()
def create_cursor(self, name=None):
return FormatStylePlaceholderCursor(self.connection)
def _commit(self):
if self.connection is not None:
with wrap_oracle_errors():
return self.connection.commit()
# Oracle doesn't support releasing savepoints. But we fake them when query
# logging is enabled to keep query counts consistent with other backends.
def _savepoint_commit(self, sid):
if self.queries_logged:
self.queries_log.append({
'sql': '-- RELEASE SAVEPOINT %s (faked)' % self.ops.quote_name(sid),
'time': '0.000',
})
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.
"""
self.cursor().execute('SET CONSTRAINTS ALL IMMEDIATE')
self.cursor().execute('SET CONSTRAINTS ALL DEFERRED')
def is_usable(self):
try:
self.connection.ping()
except Database.Error:
return False
else:
return True
@cached_property
def oracle_version(self):
with self.temporary_connection():
return tuple(int(x) for x in self.connection.version.split('.'))
class OracleParam:
"""
Wrapper object for formatting parameters for Oracle. If the string
representation of the value is large enough (greater than 4000 characters)
the input size needs to be set as CLOB. Alternatively, if the parameter
has an `input_size` attribute, then the value of the `input_size` attribute
will be used instead. Otherwise, no input size will be set for the
parameter when executing the query.
"""
def __init__(self, param, cursor, strings_only=False):
# With raw SQL queries, datetimes can reach this function
# without being converted by DateTimeField.get_db_prep_value.
if settings.USE_TZ and (isinstance(param, datetime.datetime) and
not isinstance(param, Oracle_datetime)):
param = Oracle_datetime.from_datetime(param)
string_size = 0
# Oracle doesn't recognize True and False correctly.
if param is True:
param = 1
elif param is False:
param = 0
if hasattr(param, 'bind_parameter'):
self.force_bytes = param.bind_parameter(cursor)
elif isinstance(param, (Database.Binary, datetime.timedelta)):
self.force_bytes = param
else:
# To transmit to the database, we need Unicode if supported
# To get size right, we must consider bytes.
self.force_bytes = force_str(param, cursor.charset, strings_only)
if isinstance(self.force_bytes, str):
# We could optimize by only converting up to 4000 bytes here
string_size = len(force_bytes(param, cursor.charset, strings_only))
if hasattr(param, 'input_size'):
# If parameter has `input_size` attribute, use that.
self.input_size = param.input_size
elif string_size > 4000:
# Mark any string param greater than 4000 characters as a CLOB.
self.input_size = Database.CLOB
elif isinstance(param, datetime.datetime):
self.input_size = Database.TIMESTAMP
else:
self.input_size = None
class VariableWrapper:
"""
An adapter class for cursor variables that prevents the wrapped object
from being converted into a string when used to instantiate an OracleParam.
This can be used generally for any other object that should be passed into
Cursor.execute as-is.
"""
def __init__(self, var):
self.var = var
def bind_parameter(self, cursor):
return self.var
def __getattr__(self, key):
return getattr(self.var, key)
def __setattr__(self, key, value):
if key == 'var':
self.__dict__[key] = value
else:
setattr(self.var, key, value)
class FormatStylePlaceholderCursor:
"""
Django uses "format" (e.g. '%s') style placeholders, but Oracle uses ":var"
style. This fixes it -- but note that if you want to use a literal "%s" in
a query, you'll need to use "%%s".
"""
charset = 'utf-8'
def __init__(self, connection):
self.cursor = connection.cursor()
self.cursor.outputtypehandler = self._output_type_handler
@staticmethod
def _output_number_converter(value):
return decimal.Decimal(value) if '.' in value else int(value)
@staticmethod
def _get_decimal_converter(precision, scale):
if scale == 0:
return int
context = decimal.Context(prec=precision)
quantize_value = decimal.Decimal(1).scaleb(-scale)
return lambda v: decimal.Decimal(v).quantize(quantize_value, context=context)
@staticmethod
def _output_type_handler(cursor, name, defaultType, length, precision, scale):
"""
Called for each db column fetched from cursors. Return numbers as the
appropriate Python type.
"""
if defaultType == Database.NUMBER:
if scale == -127:
if precision == 0:
# NUMBER column: decimal-precision floating point.
# This will normally be an integer from a sequence,
# but it could be a decimal value.
outconverter = FormatStylePlaceholderCursor._output_number_converter
else:
# FLOAT column: binary-precision floating point.
# This comes from FloatField columns.
outconverter = float
elif precision > 0:
# NUMBER(p,s) column: decimal-precision fixed point.
# This comes from IntegerField and DecimalField columns.
outconverter = FormatStylePlaceholderCursor._get_decimal_converter(precision, scale)
else:
# No type information. This normally comes from a
# mathematical expression in the SELECT list. Guess int
# or Decimal based on whether it has a decimal point.
outconverter = FormatStylePlaceholderCursor._output_number_converter
return cursor.var(
Database.STRING,
size=255,
arraysize=cursor.arraysize,
outconverter=outconverter,
)
def _format_params(self, params):
try:
return {k: OracleParam(v, self, True) for k, v in params.items()}
except AttributeError:
return tuple(OracleParam(p, self, True) for p in params)
def _guess_input_sizes(self, params_list):
# Try dict handling; if that fails, treat as sequence
if hasattr(params_list[0], 'keys'):
sizes = {}
for params in params_list:
for k, value in params.items():
if value.input_size:
sizes[k] = value.input_size
if sizes:
self.setinputsizes(**sizes)
else:
# It's not a list of dicts; it's a list of sequences
sizes = [None] * len(params_list[0])
for params in params_list:
for i, value in enumerate(params):
if value.input_size:
sizes[i] = value.input_size
if sizes:
self.setinputsizes(*sizes)
def _param_generator(self, params):
# Try dict handling; if that fails, treat as sequence
if hasattr(params, 'items'):
return {k: v.force_bytes for k, v in params.items()}
else:
return [p.force_bytes for p in params]
def _fix_for_params(self, query, params, unify_by_values=False):
# cx_Oracle wants no trailing ';' for SQL statements. For PL/SQL, it
# it does want a trailing ';' but not a trailing '/'. However, these
# characters must be included in the original query in case the query
# is being passed to SQL*Plus.
if query.endswith(';') or query.endswith('/'):
query = query[:-1]
if params is None:
params = []
elif hasattr(params, 'keys'):
# Handle params as dict
args = {k: ":%s" % k for k in params}
query = query % args
elif unify_by_values and params:
# Handle params as a dict with unified query parameters by their
# values. It can be used only in single query execute() because
# executemany() shares the formatted query with each of the params
# list. e.g. for input params = [0.75, 2, 0.75, 'sth', 0.75]
# params_dict = {0.75: ':arg0', 2: ':arg1', 'sth': ':arg2'}
# args = [':arg0', ':arg1', ':arg0', ':arg2', ':arg0']
# params = {':arg0': 0.75, ':arg1': 2, ':arg2': 'sth'}
params_dict = {param: ':arg%d' % i for i, param in enumerate(set(params))}
args = [params_dict[param] for param in params]
params = {value: key for key, value in params_dict.items()}
query = query % tuple(args)
else:
# Handle params as sequence
args = [(':arg%d' % i) for i in range(len(params))]
query = query % tuple(args)
return query, self._format_params(params)
def execute(self, query, params=None):
query, params = self._fix_for_params(query, params, unify_by_values=True)
self._guess_input_sizes([params])
with wrap_oracle_errors():
return self.cursor.execute(query, self._param_generator(params))
def executemany(self, query, params=None):
if not params:
# No params given, nothing to do
return None
# uniform treatment for sequences and iterables
params_iter = iter(params)
query, firstparams = self._fix_for_params(query, next(params_iter))
# we build a list of formatted params; as we're going to traverse it
# more than once, we can't make it lazy by using a generator
formatted = [firstparams] + [self._format_params(p) for p in params_iter]
self._guess_input_sizes(formatted)
with wrap_oracle_errors():
return self.cursor.executemany(query, [self._param_generator(p) for p in formatted])
def close(self):
try:
self.cursor.close()
except Database.InterfaceError:
# already closed
pass
def var(self, *args):
return VariableWrapper(self.cursor.var(*args))
def arrayvar(self, *args):
return VariableWrapper(self.cursor.arrayvar(*args))
def __getattr__(self, attr):
return getattr(self.cursor, attr)
def __iter__(self):
return iter(self.cursor)
|
d62da08b55650eb09d1cb073d8e00e55a4ca163497f99c8ebde3c1969b4f52a6 | import datetime
import re
import uuid
from functools import lru_cache
from django.conf import settings
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.backends.utils import strip_quotes, truncate_name
from django.db.utils import DatabaseError
from django.utils import timezone
from django.utils.encoding import force_bytes, force_str
from django.utils.functional import cached_property
from .base import Database
from .utils import BulkInsertMapper, InsertIdVar, Oracle_datetime
class DatabaseOperations(BaseDatabaseOperations):
# Oracle uses NUMBER(11) and NUMBER(19) for integer fields.
integer_field_ranges = {
'SmallIntegerField': (-99999999999, 99999999999),
'IntegerField': (-99999999999, 99999999999),
'BigIntegerField': (-9999999999999999999, 9999999999999999999),
'PositiveSmallIntegerField': (0, 99999999999),
'PositiveIntegerField': (0, 99999999999),
}
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)',
'TextField': cast_char_field_without_max_length,
}
def cache_key_culling_sql(self):
return 'SELECT cache_key FROM %s 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 == '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):
# 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 = re.compile(r'^[\w/:+-]+$')
def _prepare_tzname_delta(self, tzname):
if '+' in tzname:
return tzname[tzname.find('+'):]
elif '-' in tzname:
return tzname[tzname.find('-'):]
return tzname
def _convert_field_to_tz(self, field_name, tzname):
if not settings.USE_TZ:
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 where only the date
# part is ignored, convert the field to the specified timezone.
return self._convert_field_to_tz(field_name, tzname)
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):
# 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.
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 == 'TextField':
converters.append(self.convert_textfield_value)
elif internal_type == 'BinaryField':
converters.append(self.convert_binaryfield_value)
elif internal_type in ['BooleanField', 'NullBooleanField']:
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.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_id(self, cursor):
value = cursor._insert_id_var.getvalue()
if value is None or value == []:
# cx_Oracle < 6.3 returns None, >= 6.3 returns empty list.
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).'
)
# cx_Oracle < 7 returns value, >= 7 returns list with single value.
return value[0] if isinstance(value, list) else value
def field_cast_sql(self, db_type, internal_type):
if db_type and db_type.endswith('LOB'):
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/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)"
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.upper(), 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 random_function_sql(self):
return "DBMS_RANDOM.RANDOM"
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_id(self):
return "RETURNING %s INTO %%s", (InsertIdVar(),)
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, sequences, allow_cascade=False):
if tables:
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
]
# 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
else:
return []
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):
from django.db import models
output = []
query = self._sequence_reset_sql
for model in model_list:
for f in model._meta.local_fields:
if isinstance(f, models.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
for f in model._meta.many_to_many:
if not f.remote_field.through:
no_autofield_sequence_name = self._get_no_autofield_sequence_name(f.m2m_db_table())
table = self.quote_name(f.m2m_db_table())
column = self.quote_name('id')
output.append(query % {
'no_autofield_sequence_name': no_autofield_sequence_name,
'table': table,
'column': column,
'table_name': strip_quotes(table),
'column_name': 'ID',
})
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 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)
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
return "NUMTODSINTERVAL(TO_NUMBER(%s - %s), 'DAY')" % (lhs_sql, rhs_sql), lhs_params + rhs_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)
|
8057b0c6b458a7f2ba27404771aacdd0d88d29ad43f65765f70b133b5b4c0907 | import copy
import datetime
import re
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.utils import DatabaseError
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_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, 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'))
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)
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 _unique_should_be_added(self, old_field, new_field):
return (
super()._unique_should_be_added(old_field, new_field) and
not self._field_became_primary_key(old_field, new_field)
)
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),
})
|
25860139902bf35e22122d96384393eed7027c972593c80c80fc7366ee1207c7 | import shutil
import subprocess
from django.db.backends.base.client import BaseDatabaseClient
class DatabaseClient(BaseDatabaseClient):
executable_name = 'sqlplus'
wrapper_name = 'rlwrap'
def runshell(self):
conn_string = self.connection._connect_string()
args = [self.executable_name, "-L", conn_string]
wrapper_path = shutil.which(self.wrapper_name)
if wrapper_path:
args = [wrapper_path, *args]
subprocess.check_call(args)
|
42b96e6b4cee98e6d133a6a45ad5f256fc5c29f551394a73ac3837ceb640bca6 | import datetime
from .base import Database
class InsertIdVar:
"""
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.
"""
def bind_parameter(self, cursor):
param = cursor.cursor.var(int)
cursor._insert_id_var = param
return param
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))'
NUMBER = 'TO_NUMBER(%s)'
TIMESTAMP = 'TO_TIMESTAMP(%s)'
types = {
'BigIntegerField': NUMBER,
'BinaryField': BLOB,
'BooleanField': NUMBER,
'DateField': DATE,
'DateTimeField': TIMESTAMP,
'DecimalField': NUMBER,
'DurationField': INTERVAL,
'FloatField': NUMBER,
'IntegerField': NUMBER,
'NullBooleanField': NUMBER,
'PositiveIntegerField': NUMBER,
'PositiveSmallIntegerField': NUMBER,
'SmallIntegerField': NUMBER,
'TimeField': TIMESTAMP,
}
|
1603548f790c68ae66de1fd68dcc3ba4400cab133ab6df3b1ff76df363a098c1 | import sys
from django.conf import settings
from django.db.backends.base.creation import BaseDatabaseCreation
from django.db.utils import DatabaseError
from django.utils.crypto import get_random_string
from django.utils.functional import cached_property
TEST_DATABASE_PREFIX = 'test_'
class DatabaseCreation(BaseDatabaseCreation):
@cached_property
def _maindb_connection(self):
"""
This is analogous to other backends' `_nodb_connection` property,
which allows access to an "administrative" connection which can
be used to manage the test databases.
For Oracle, the only connection that can be used for that purpose
is the main (non-test) connection.
"""
settings_dict = settings.DATABASES[self.connection.alias]
user = settings_dict.get('SAVED_USER') or settings_dict['USER']
password = settings_dict.get('SAVED_PASSWORD') or settings_dict['PASSWORD']
settings_dict = {**settings_dict, 'USER': user, 'PASSWORD': password}
DatabaseWrapper = type(self.connection)
return DatabaseWrapper(settings_dict, alias=self.connection.alias)
def _create_test_db(self, verbosity=1, autoclobber=False, keepdb=False):
parameters = self._get_test_db_params()
with self._maindb_connection.cursor() as cursor:
if self._test_database_create():
try:
self._execute_test_db_creation(cursor, parameters, verbosity, keepdb)
except Exception as e:
if 'ORA-01543' not in str(e):
# All errors except "tablespace already exists" cancel tests
self.log('Got an error creating the test database: %s' % e)
sys.exit(2)
if not autoclobber:
confirm = input(
"It appears the test database, %s, already exists. "
"Type 'yes' to delete it, or 'no' to cancel: " % parameters['user'])
if autoclobber or confirm == 'yes':
if verbosity >= 1:
self.log("Destroying old test database for alias '%s'..." % self.connection.alias)
try:
self._execute_test_db_destruction(cursor, parameters, verbosity)
except DatabaseError as e:
if 'ORA-29857' in str(e):
self._handle_objects_preventing_db_destruction(cursor, parameters,
verbosity, autoclobber)
else:
# Ran into a database error that isn't about leftover objects in the tablespace
self.log('Got an error destroying the old test database: %s' % e)
sys.exit(2)
except Exception as e:
self.log('Got an error destroying the old test database: %s' % e)
sys.exit(2)
try:
self._execute_test_db_creation(cursor, parameters, verbosity, 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)
if self._test_user_create():
if verbosity >= 1:
self.log('Creating test user...')
try:
self._create_test_user(cursor, parameters, verbosity, keepdb)
except Exception as e:
if 'ORA-01920' not in str(e):
# All errors except "user already exists" cancel tests
self.log('Got an error creating the test user: %s' % e)
sys.exit(2)
if not autoclobber:
confirm = input(
"It appears the test user, %s, already exists. Type "
"'yes' to delete it, or 'no' to cancel: " % parameters['user'])
if autoclobber or confirm == 'yes':
try:
if verbosity >= 1:
self.log('Destroying old test user...')
self._destroy_test_user(cursor, parameters, verbosity)
if verbosity >= 1:
self.log('Creating test user...')
self._create_test_user(cursor, parameters, verbosity, keepdb)
except Exception as e:
self.log('Got an error recreating the test user: %s' % e)
sys.exit(2)
else:
self.log('Tests cancelled.')
sys.exit(1)
self._maindb_connection.close() # done with main user -- test user and tablespaces created
self._switch_to_test_user(parameters)
return self.connection.settings_dict['NAME']
def _switch_to_test_user(self, parameters):
"""
Switch to the user that's used for creating the test database.
Oracle doesn't have the concept of separate databases under the same
user, so a separate user is used; see _create_test_db(). The main user
is also needed for cleanup when testing is completed, so save its
credentials in the SAVED_USER/SAVED_PASSWORD key in the settings dict.
"""
real_settings = settings.DATABASES[self.connection.alias]
real_settings['SAVED_USER'] = self.connection.settings_dict['SAVED_USER'] = \
self.connection.settings_dict['USER']
real_settings['SAVED_PASSWORD'] = self.connection.settings_dict['SAVED_PASSWORD'] = \
self.connection.settings_dict['PASSWORD']
real_test_settings = real_settings['TEST']
test_settings = self.connection.settings_dict['TEST']
real_test_settings['USER'] = real_settings['USER'] = test_settings['USER'] = \
self.connection.settings_dict['USER'] = parameters['user']
real_settings['PASSWORD'] = self.connection.settings_dict['PASSWORD'] = parameters['password']
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['USER'] = primary_settings_dict['USER']
self.connection.settings_dict['PASSWORD'] = primary_settings_dict['PASSWORD']
def _handle_objects_preventing_db_destruction(self, cursor, parameters, verbosity, autoclobber):
# There are objects in the test tablespace which prevent dropping it
# The easy fix is to drop the test user -- but are we allowed to do so?
self.log(
'There are objects in the old test database which prevent its destruction.\n'
'If they belong to the test user, deleting the user will allow the test '
'database to be recreated.\n'
'Otherwise, you will need to find and remove each of these objects, '
'or use a different tablespace.\n'
)
if self._test_user_create():
if not autoclobber:
confirm = input("Type 'yes' to delete user %s: " % parameters['user'])
if autoclobber or confirm == 'yes':
try:
if verbosity >= 1:
self.log('Destroying old test user...')
self._destroy_test_user(cursor, parameters, verbosity)
except Exception as e:
self.log('Got an error destroying the test user: %s' % e)
sys.exit(2)
try:
if verbosity >= 1:
self.log("Destroying old test database for alias '%s'..." % self.connection.alias)
self._execute_test_db_destruction(cursor, parameters, verbosity)
except Exception as e:
self.log('Got an error destroying the test database: %s' % e)
sys.exit(2)
else:
self.log('Tests cancelled -- test database cannot be recreated.')
sys.exit(1)
else:
self.log("Django is configured to use pre-existing test user '%s',"
" and will not attempt to delete it." % parameters['user'])
self.log('Tests cancelled -- test database cannot be recreated.')
sys.exit(1)
def _destroy_test_db(self, test_database_name, verbosity=1):
"""
Destroy a test database, prompting the user for confirmation if the
database already exists. Return the name of the test database created.
"""
self.connection.settings_dict['USER'] = self.connection.settings_dict['SAVED_USER']
self.connection.settings_dict['PASSWORD'] = self.connection.settings_dict['SAVED_PASSWORD']
self.connection.close()
parameters = self._get_test_db_params()
with self._maindb_connection.cursor() as cursor:
if self._test_user_create():
if verbosity >= 1:
self.log('Destroying test user...')
self._destroy_test_user(cursor, parameters, verbosity)
if self._test_database_create():
if verbosity >= 1:
self.log('Destroying test database tables...')
self._execute_test_db_destruction(cursor, parameters, verbosity)
self._maindb_connection.close()
def _execute_test_db_creation(self, cursor, parameters, verbosity, keepdb=False):
if verbosity >= 2:
self.log('_create_test_db(): dbname = %s' % parameters['user'])
if self._test_database_oracle_managed_files():
statements = [
"""
CREATE TABLESPACE %(tblspace)s
DATAFILE SIZE %(size)s
AUTOEXTEND ON NEXT %(extsize)s MAXSIZE %(maxsize)s
""",
"""
CREATE TEMPORARY TABLESPACE %(tblspace_temp)s
TEMPFILE SIZE %(size_tmp)s
AUTOEXTEND ON NEXT %(extsize_tmp)s MAXSIZE %(maxsize_tmp)s
""",
]
else:
statements = [
"""
CREATE TABLESPACE %(tblspace)s
DATAFILE '%(datafile)s' SIZE %(size)s REUSE
AUTOEXTEND ON NEXT %(extsize)s MAXSIZE %(maxsize)s
""",
"""
CREATE TEMPORARY TABLESPACE %(tblspace_temp)s
TEMPFILE '%(datafile_tmp)s' SIZE %(size_tmp)s REUSE
AUTOEXTEND ON NEXT %(extsize_tmp)s MAXSIZE %(maxsize_tmp)s
""",
]
# Ignore "tablespace already exists" error when keepdb is on.
acceptable_ora_err = 'ORA-01543' if keepdb else None
self._execute_allow_fail_statements(cursor, statements, parameters, verbosity, acceptable_ora_err)
def _create_test_user(self, cursor, parameters, verbosity, keepdb=False):
if verbosity >= 2:
self.log('_create_test_user(): username = %s' % parameters['user'])
statements = [
"""CREATE USER %(user)s
IDENTIFIED BY "%(password)s"
DEFAULT TABLESPACE %(tblspace)s
TEMPORARY TABLESPACE %(tblspace_temp)s
QUOTA UNLIMITED ON %(tblspace)s
""",
"""GRANT CREATE SESSION,
CREATE TABLE,
CREATE SEQUENCE,
CREATE PROCEDURE,
CREATE TRIGGER
TO %(user)s""",
]
# Ignore "user already exists" error when keepdb is on
acceptable_ora_err = 'ORA-01920' if keepdb else None
success = self._execute_allow_fail_statements(cursor, statements, parameters, verbosity, acceptable_ora_err)
# If the password was randomly generated, change the user accordingly.
if not success and self._test_settings_get('PASSWORD') is None:
set_password = 'ALTER USER %(user)s IDENTIFIED BY "%(password)s"'
self._execute_statements(cursor, [set_password], parameters, verbosity)
# Most test suites can be run without "create view" and
# "create materialized view" privileges. But some need it.
for object_type in ('VIEW', 'MATERIALIZED VIEW'):
extra = 'GRANT CREATE %(object_type)s TO %(user)s'
parameters['object_type'] = object_type
success = self._execute_allow_fail_statements(cursor, [extra], parameters, verbosity, 'ORA-01031')
if not success and verbosity >= 2:
self.log('Failed to grant CREATE %s permission to test user. This may be ok.' % object_type)
def _execute_test_db_destruction(self, cursor, parameters, verbosity):
if verbosity >= 2:
self.log('_execute_test_db_destruction(): dbname=%s' % parameters['user'])
statements = [
'DROP TABLESPACE %(tblspace)s INCLUDING CONTENTS AND DATAFILES CASCADE CONSTRAINTS',
'DROP TABLESPACE %(tblspace_temp)s INCLUDING CONTENTS AND DATAFILES CASCADE CONSTRAINTS',
]
self._execute_statements(cursor, statements, parameters, verbosity)
def _destroy_test_user(self, cursor, parameters, verbosity):
if verbosity >= 2:
self.log('_destroy_test_user(): user=%s' % parameters['user'])
self.log('Be patient. This can take some time...')
statements = [
'DROP USER %(user)s CASCADE',
]
self._execute_statements(cursor, statements, parameters, verbosity)
def _execute_statements(self, cursor, statements, parameters, verbosity, allow_quiet_fail=False):
for template in statements:
stmt = template % parameters
if verbosity >= 2:
print(stmt)
try:
cursor.execute(stmt)
except Exception as err:
if (not allow_quiet_fail) or verbosity >= 2:
self.log('Failed (%s)' % (err))
raise
def _execute_allow_fail_statements(self, cursor, statements, parameters, verbosity, acceptable_ora_err):
"""
Execute statements which are allowed to fail silently if the Oracle
error code given by `acceptable_ora_err` is raised. Return True if the
statements execute without an exception, or False otherwise.
"""
try:
# Statement can fail when acceptable_ora_err is not None
allow_quiet_fail = acceptable_ora_err is not None and len(acceptable_ora_err) > 0
self._execute_statements(cursor, statements, parameters, verbosity, allow_quiet_fail=allow_quiet_fail)
return True
except DatabaseError as err:
description = str(err)
if acceptable_ora_err is None or acceptable_ora_err not in description:
raise
return False
def _get_test_db_params(self):
return {
'dbname': self._test_database_name(),
'user': self._test_database_user(),
'password': self._test_database_passwd(),
'tblspace': self._test_database_tblspace(),
'tblspace_temp': self._test_database_tblspace_tmp(),
'datafile': self._test_database_tblspace_datafile(),
'datafile_tmp': self._test_database_tblspace_tmp_datafile(),
'maxsize': self._test_database_tblspace_maxsize(),
'maxsize_tmp': self._test_database_tblspace_tmp_maxsize(),
'size': self._test_database_tblspace_size(),
'size_tmp': self._test_database_tblspace_tmp_size(),
'extsize': self._test_database_tblspace_extsize(),
'extsize_tmp': self._test_database_tblspace_tmp_extsize(),
}
def _test_settings_get(self, key, default=None, prefixed=None):
"""
Return a value from the test settings dict, or a given default, or a
prefixed entry from the main settings dict.
"""
settings_dict = self.connection.settings_dict
val = settings_dict['TEST'].get(key, default)
if val is None and prefixed:
val = TEST_DATABASE_PREFIX + settings_dict[prefixed]
return val
def _test_database_name(self):
return self._test_settings_get('NAME', prefixed='NAME')
def _test_database_create(self):
return self._test_settings_get('CREATE_DB', default=True)
def _test_user_create(self):
return self._test_settings_get('CREATE_USER', default=True)
def _test_database_user(self):
return self._test_settings_get('USER', prefixed='USER')
def _test_database_passwd(self):
password = self._test_settings_get('PASSWORD')
if password is None and self._test_user_create():
# Oracle passwords are limited to 30 chars and can't contain symbols.
password = get_random_string(length=30)
return password
def _test_database_tblspace(self):
return self._test_settings_get('TBLSPACE', prefixed='USER')
def _test_database_tblspace_tmp(self):
settings_dict = self.connection.settings_dict
return settings_dict['TEST'].get('TBLSPACE_TMP',
TEST_DATABASE_PREFIX + settings_dict['USER'] + '_temp')
def _test_database_tblspace_datafile(self):
tblspace = '%s.dbf' % self._test_database_tblspace()
return self._test_settings_get('DATAFILE', default=tblspace)
def _test_database_tblspace_tmp_datafile(self):
tblspace = '%s.dbf' % self._test_database_tblspace_tmp()
return self._test_settings_get('DATAFILE_TMP', default=tblspace)
def _test_database_tblspace_maxsize(self):
return self._test_settings_get('DATAFILE_MAXSIZE', default='500M')
def _test_database_tblspace_tmp_maxsize(self):
return self._test_settings_get('DATAFILE_TMP_MAXSIZE', default='500M')
def _test_database_tblspace_size(self):
return self._test_settings_get('DATAFILE_SIZE', default='50M')
def _test_database_tblspace_tmp_size(self):
return self._test_settings_get('DATAFILE_TMP_SIZE', default='50M')
def _test_database_tblspace_extsize(self):
return self._test_settings_get('DATAFILE_EXTSIZE', default='25M')
def _test_database_tblspace_tmp_extsize(self):
return self._test_settings_get('DATAFILE_TMP_EXTSIZE', default='25M')
def _test_database_oracle_managed_files(self):
return self._test_settings_get('ORACLE_MANAGED_FILES', default=False)
def _get_test_db_name(self):
"""
Return the 'production' DB name to get the test DB creation machinery
to work. This isn't a great deal in this case because DB names as
handled by Django don't have real counterparts in Oracle.
"""
return self.connection.settings_dict['NAME']
def test_db_signature(self):
settings_dict = self.connection.settings_dict
return (
settings_dict['HOST'],
settings_dict['PORT'],
settings_dict['ENGINE'],
settings_dict['NAME'],
self._test_database_user(),
)
|
6fb831f1badfdfa5ffcf3b94da378ee2212849c1dc04190927a84139857875fd | from django.db.utils import ProgrammingError
from django.utils.functional import cached_property
class BaseDatabaseFeatures:
gis_enabled = False
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
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
# 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
# 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
# The database's limit on the number of query parameters.
max_query_params = None
# Can an object have an autoincrement primary key of 0? MySQL says No.
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
# date_interval_sql can properly handle mixed Date/DateTime fields and timedeltas
supports_mixed_date_datetime_comparisons = True
# 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
# Can the backend introspect an AutoField, instead of an IntegerField?
can_introspect_autofield = False
# Can the backend introspect a BigIntegerField, instead of an IntegerField?
can_introspect_big_integer_field = True
# Can the backend introspect an BinaryField, instead of an TextField?
can_introspect_binary_field = True
# Can the backend introspect an DecimalField, instead of an FloatField?
can_introspect_decimal_field = True
# Can the backend introspect a DurationField, instead of a BigIntegerField?
can_introspect_duration_field = True
# Can the backend introspect an IPAddressField, instead of an CharField?
can_introspect_ip_address_field = False
# Can the backend introspect a PositiveIntegerField, instead of an IntegerField?
can_introspect_positive_integer_field = False
# Can the backend introspect a SmallIntegerField, instead of an IntegerField?
can_introspect_small_integer_field = False
# Can the backend introspect a TimeField, instead of a DateTimeField?
can_introspect_time_field = True
# Some backends may not be able to differentiate BigAutoField from other
# fields such as AutoField.
introspected_big_auto_field_type = 'BigAutoField'
# Some backends may not be able to differentiate BooleanField from other
# fields such as IntegerField.
introspected_boolean_field_type = 'BooleanField'
# 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 support CHECK constraints?
supports_column_check_constraints = True
supports_table_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 = True
# 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
# 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
# Convert CharField results from bytes to str in database functions.
db_functions_convert_bytes_to_str = 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 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 database allow more than one constraint or index on the same
# field(s)?
allows_multiple_constraints_on_same_fields = True
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
|
c7ec77da304c4864af06719bffd10580a5a4d124d86ce8acf58a05e1ccc49b49 | 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')
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 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.
"""
from django.apps import apps
from django.db import router
tables = set()
for app_config in apps.get_app_configs():
for model in router.get_migratable_models(app_config, self.connection.alias):
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.
"""
from django.apps import apps
from django.db import router
all_models = []
for app_config in apps.get_app_configs():
all_models.extend(router.get_migratable_models(app_config, self.connection.alias))
tables = set(map(self.identifier_converter, tables))
return {
m for m in all_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.
"""
from django.apps import apps
from django.db import router
sequence_list = []
with self.connection.cursor() as cursor:
for app_config in apps.get_app_configs():
for model in router.get_migratable_models(app_config, self.connection.alias):
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_key_columns(self, cursor, table_name):
"""
Backends can override this to return a list of:
(column_name, referenced_table_name, referenced_column_name)
for all key columns in given table.
"""
raise NotImplementedError('subclasses of BaseDatabaseIntrospection may require a get_key_columns() 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')
|
9e45cced229cdf5f498041b3d1ba33ff18e2d8471a4a33de622ec64dbfbcebe3 | import copy
import threading
import time
import warnings
from collections import deque
from contextlib import contextmanager
import _thread
import pytz
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import DEFAULT_DB_ALIAS
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 DatabaseError, DatabaseErrorWrapper
from django.utils import timezone
from django.utils.functional import cached_property
NO_DB_ALIAS = '__no_db__'
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 = []
# 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
# 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 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):
"""
Time zone for datetimes stored as naive values in the database.
Return a tzinfo object or None.
This is only needed when time zone support is enabled and the database
doesn't support time zones. (When the database supports time zones,
the adapter handles aware datetimes so Django doesn't need to.)
"""
if not settings.USE_TZ:
return None
elif self.features.supports_timezones:
return None
elif self.settings_dict['TIME_ZONE'] is None:
return timezone.utc
else:
return pytz.timezone(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 #####
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.needs_rollback = False
# Reset parameters defining when to close the connection
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
# 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:
if not settings.USE_TZ:
raise ImproperlyConfigured(
"Connection '%s' cannot set TIME_ZONE because USE_TZ is "
"False." % self.alias)
elif self.features.supports_timezones:
raise ImproperlyConfigured(
"Connection '%s' cannot set TIME_ZONE because its engine "
"handles time zones conversions natively." % self.alias)
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.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 #####
def cursor(self):
"""Create a cursor, opening a connection if necessary."""
return self._cursor()
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
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 = []
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 #####
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
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
]
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)
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 explcit 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.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_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:
# 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
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()
@property
def _nodb_connection(self):
"""
Return 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.
"""
return self.__class__({**self.settings_dict, 'NAME': None}, alias=NO_DB_ALIAS)
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 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)
|
6ab54e37fc2e1909fe9d63ef8b738a988771f66b102f609e1749a54ff82eac47 | 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),
'PositiveSmallIntegerField': (0, 32767),
'PositiveIntegerField': (0, 2147483647),
}
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 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.
"""
return "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_interval_sql(self, timedelta):
"""
Implement the date interval functionality for expressions.
"""
raise NotImplementedError('subclasses of BaseDatabaseOperations may require a date_interval_sql() method')
def date_trunc_sql(self, lookup_type, field_name):
"""
Given a lookup_type of 'year', 'month', or 'day', return the SQL that
truncates the given date field field_name to a date object with only
the given specificity.
"""
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):
"""
Given a lookup_type of 'hour', 'minute' or 'second', return the SQL
that truncates the given time field field_name to a time object with
only the given specificity.
"""
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_id(self, cursor):
"""
Given a cursor object that has just performed an INSERT...RETURNING
statement into a table that has an auto-incrementing ID, return the
newly created ID.
"""
return cursor.fetchone()[0]
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=()):
"""
Return the FOR UPDATE SQL clause to lock rows for an update operation.
"""
return 'FOR UPDATE%s%s%s' % (
' 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_id(self):
"""
For backends that support returning the last insert ID 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 random_function_sql(self):
"""Return an SQL expression that returns a random value."""
return 'RANDOM()'
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, sequences, 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) and the SQL statements required to reset the 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.
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 a sql_flush() method')
def execute_sql_flush(self, using, sql_list):
"""Execute a list of SQL statements to flush the database."""
with transaction.atomic(using=using, 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
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
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):
"""
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.
"""
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):
"""
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.
"""
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 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):
return self.window_frame_rows_start_end(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, ignore_conflicts=False):
return 'INSERT INTO'
def ignore_conflicts_suffix_sql(self, ignore_conflicts=None):
return ''
|
ea6cafec4045a4fc405827f6fe93370a29cd7a5e966289851dffd96b9896e1f4 | import logging
from datetime import datetime
from django.db.backends.ddl_references import (
Columns, ForeignKeyName, IndexName, Statement, Table,
)
from django.db.backends.utils import names_digest, split_identifier
from django.db.models import Index
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 _related_non_m2m_objects(old_field, new_field):
# Filter out m2m objects from reverse relations.
# Return (old_relation, new_relation) tuples.
return zip(
(obj for obj in old_field.model._meta.related_objects if _is_relevant_relation(obj, old_field)),
(obj for obj in new_field.model._meta.related_objects if _is_relevant_relation(obj, new_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_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)"
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)"
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)%(extra)s%(condition)s"
sql_create_unique_index = "CREATE UNIQUE INDEX %(name)s ON %(table)s (%(columns)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.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 afterwards, like geometry fields with some backends).
for fields in model._meta.unique_together:
columns = [model._meta.get_field(field).column for field in fields]
self.deferred_sql.append(self._create_unique_sql(model, columns))
# 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'):
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 column_sql(self, model, field, include_default=False):
"""
Take a field and return its column definition.
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)
sql = db_params['type']
params = []
# Check for fields that aren't actually columns (e.g. M2M)
if sql is None:
return None, None
# Work out nullability
null = field.null
# If we were told to include a default value, do so
include_default = include_default and not self.skip_default(field)
if include_default:
default_value = self.effective_default(field)
if default_value is not None:
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
sql += " DEFAULT %s" % self.prepare_default(default_value)
else:
sql += " DEFAULT %s"
params += [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 null and not self.connection.features.implied_column_null:
sql += " NULL"
elif not null:
sql += " NOT NULL"
# Primary key/unique outputs
if field.primary_key:
sql += " PRIMARY KEY"
elif field.unique:
sql += " 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:
sql += " %s" % self.connection.ops.tablespace_sql(tablespace, inline=True)
# Return the sql
return sql, 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 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'
)
@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 = bytes()
else:
default = str()
elif getattr(field, 'auto_now', False) or getattr(field, 'auto_now_add', False):
default = datetime.now()
internal_type = field.get_internal_type()
if internal_type == 'DateField':
default = default.date()
elif internal_type == 'TimeField':
default = default.time()
elif internal_type == 'DateTimeField':
default = timezone.now()
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."""
self.execute(index.create_sql(model, self), params=None)
def remove_index(self, model, index):
"""Remove an index from a model."""
self.execute(index.remove_sql(model, self))
def add_constraint(self, model, constraint):
"""Add a check constraint to a model."""
sql = constraint.create_sql(model, self)
if sql:
self.execute(sql)
def remove_constraint(self, model, constraint):
"""Remove a check 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 fields in news.difference(olds):
columns = [model._meta.get_field(field).column for field in fields]
self.execute(self._create_unique_sql(model, columns))
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}, 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, 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
definition += " " + self.sql_create_column_inline_fk % {
'name': self._fk_constraint_name(model, field, constraint_suffix),
'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(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.
"""
# 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 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 = (
(
(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 = []
# Type change?
if 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?
old_default = self.effective_default(old_field)
new_default = self.effective_default(new_field)
needs_database_default = (
old_field.null and
not new_field.null and
old_default != new_default and
new_default is not None and
not self.skip_default(new_field)
)
if needs_database_default:
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.column]))
# 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, [new_field]))
# Type alteration on primary key? Then we need to alter the column
# referring to us.
rels_to_update = []
if old_field.primary_key and new_field.primary_key and old_type != new_type:
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 (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 new_field.model._meta.related_objects:
if _is_relevant_relation(rel, new_field) and 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.get_internal_type() in ("CharField", "TextField")):
# 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 = '%s'
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)
sql = self.sql_alter_column_no_default if drop else 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_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 _create_index_sql(self, model, fields, *, name=None, suffix='', using='',
db_tablespace=None, col_suffixes=(), sql=None, opclasses=(),
condition=None):
"""
Return the SQL statement to create the index for one or several fields.
`sql` can be specified if the syntax differs from the standard (GIS
indexes, ...).
"""
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),
extra=tablespace_sql,
condition=(' WHERE ' + condition) if condition else '',
)
def _delete_index_sql(self, model, name):
return Statement(
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, suffix="_idx"))
for index in model._meta.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, [field]))
return output
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 old_field.unique and new_field.unique) or (
old_field.primary_key and not new_field.primary_key and new_field.unique
)
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 _unique_sql(self, model, fields, name, condition=None):
if condition:
# Databases support conditional unique constraints via a unique
# index.
sql = self._create_unique_sql(model, fields, name=name, condition=condition)
if sql:
self.deferred_sql.append(sql)
return None
constraint = self.sql_unique_constraint % {
'columns': ', '.join(map(self.quote_name, fields)),
}
return self.sql_constraint % {
'name': self.quote_name(name),
'constraint': constraint,
}
def _create_unique_sql(self, model, columns, name=None, condition=None):
def create_unique_name(*args, **kwargs):
return self.quote_name(self._create_index_name(*args, **kwargs))
table = Table(model._meta.db_table, self.quote_name)
if name is None:
name = IndexName(model._meta.db_table, columns, '_uniq', create_unique_name)
else:
name = self.quote_name(name)
columns = Columns(table, columns, self.quote_name)
if condition:
return Statement(
self.sql_create_unique_index,
table=table,
name=name,
columns=columns,
condition=' WHERE ' + condition,
) if self.connection.features.supports_partial_indexes else None
else:
return Statement(
self.sql_create_unique,
table=table,
name=name,
columns=columns,
)
def _delete_unique_sql(self, model, name, condition=None):
if condition:
return (
self._delete_constraint_sql(self.sql_delete_index, model, name)
if self.connection.features.supports_partial_indexes else None
)
return self._delete_constraint_sql(self.sql_delete_unique, 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 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)
|
ebff0820a758b88df023ecd4b416d31d46baa70389c988af8d5ef654489ec36f | 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
# 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
@property
def _nodb_connection(self):
"""
Used to be defined here, now moved to DatabaseWrapper.
"""
return self.connection._nodb_connection
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
# 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,
)
# 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()
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.
"""
# Build list of all apps to serialize
from django.db.migrations.loader import MigrationLoader
loader = MigrationLoader(self.connection)
app_list = []
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
):
app_list.append((app_config, None))
# Make a function to iteratively return every object
def get_objects():
for model in serializers.sort_dependencies(app_list):
if (model._meta.can_migrate(self.connection) and
router.allow_migrate_model(self.connection.alias, model)):
queryset = model._default_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)
for obj in serializers.deserialize("json", data, using=self.connection.alias):
obj.save()
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_connection.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.connection._nodb_connection.cursor() as cursor:
cursor.execute("DROP DATABASE %s"
% self.connection.ops.quote_name(test_database_name))
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(),
)
|
d17c0e6f2fc7ce06ce92b068df385ad6af6212d9fd6daab3911baaac7cea59a7 | import operator
from django.db.backends.base.features import BaseDatabaseFeatures
from django.utils.functional import cached_property
class DatabaseFeatures(BaseDatabaseFeatures):
empty_fetchmany_value = ()
update_can_self_select = False
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
can_introspect_autofield = True
can_introspect_binary_field = False
can_introspect_duration_field = False
can_introspect_small_integer_field = True
can_introspect_positive_integer_field = True
introspected_boolean_field_type = 'IntegerField'
supports_index_column_ordering = False
supports_timezones = False
requires_explicit_null_ordering_when_grouping = True
allows_auto_pk_0 = False
can_release_savepoints = True
atomic_transactions = False
supports_column_check_constraints = False
supports_table_check_constraints = 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
has_case_insensitive_like = False
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;
"""
db_functions_convert_bytes_to_str = True
# Alias MySQL's TRADITIONAL to TEXT for consistency with other backends.
supported_explain_formats = {'JSON', 'TEXT', 'TRADITIONAL'}
# Neither MySQL nor MariaDB support partial indexes.
supports_partial_indexes = False
@cached_property
def _mysql_storage_engine(self):
"Internal method used in Django tests. Don't rely on this from your code"
with self.connection.cursor() as cursor:
cursor.execute("SELECT ENGINE FROM INFORMATION_SCHEMA.ENGINES WHERE SUPPORT = 'DEFAULT'")
result = cursor.fetchone()
return result[0]
@cached_property
def can_introspect_foreign_keys(self):
"Confirm support for introspected foreign keys"
return self._mysql_storage_engine != 'MyISAM'
@cached_property
def has_zoneinfo_database(self):
# Test if the time zone definitions are installed.
with self.connection.cursor() as cursor:
cursor.execute("SELECT 1 FROM mysql.time_zone LIMIT 1")
return cursor.fetchone() is not None
@cached_property
def is_sql_auto_is_null_enabled(self):
with self.connection.cursor() as cursor:
cursor.execute('SELECT @@SQL_AUTO_IS_NULL')
result = cursor.fetchone()
return result and result[0] == 1
@cached_property
def supports_over_clause(self):
if self.connection.mysql_is_mariadb:
return self.connection.mysql_version >= (10, 2)
return self.connection.mysql_version >= (8, 0, 2)
@cached_property
def has_select_for_update_skip_locked(self):
return not self.connection.mysql_is_mariadb and self.connection.mysql_version >= (8, 0, 1)
has_select_for_update_nowait = property(operator.attrgetter('has_select_for_update_skip_locked'))
@cached_property
def needs_explain_extended(self):
# EXTENDED is deprecated (and not required) in MySQL 5.7.
return not self.connection.mysql_is_mariadb and self.connection.mysql_version < (5, 7)
@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):
with self.connection.cursor() as cursor:
cursor.execute('SELECT @@LOWER_CASE_TABLE_NAMES')
result = cursor.fetchone()
return result and result[0] != 0
@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
|
ae689391c088c39fb7b42eda8e6332f36cc7a649349da422a624b554b53d5700 | from collections import namedtuple
from MySQLdb.constants import FIELD_TYPE
from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo as BaseFieldInfo, TableInfo,
)
from django.db.models.indexes import Index
from django.utils.datastructures import OrderedSet
FieldInfo = namedtuple('FieldInfo', BaseFieldInfo._fields + ('extra', 'is_unsigned'))
InfoLine = namedtuple('InfoLine', 'col_name data_type max_len num_prec num_scale extra column_default 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.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'
if description.is_unsigned:
if field_type == 'IntegerField':
return 'PositiveIntegerField'
elif field_type == 'SmallIntegerField':
return 'PositiveSmallIntegerField'
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."
"""
# 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 column_type LIKE '%% unsigned' THEN 1
ELSE 0
END AS is_unsigned
FROM information_schema.columns
WHERE table_name = %s AND table_schema = DATABASE()""", [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.extra,
info.is_unsigned,
))
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 relationships to the given table.
"""
constraints = self.get_key_columns(cursor, table_name)
relations = {}
for my_fieldname, other_table, other_field in constraints:
relations[my_fieldname] = (other_field, other_table)
return relations
def get_key_columns(self, cursor, table_name):
"""
Return a list of (column_name, referenced_table_name, referenced_column_name)
for all key columns in the given table.
"""
key_columns = []
cursor.execute("""
SELECT column_name, referenced_table_name, referenced_column_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])
key_columns.extend(cursor.fetchall())
return key_columns
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", [table_name])
result = cursor.fetchone()
if not result:
return self.connection.features._mysql_storage_engine
return result[0]
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`
FROM information_schema.key_column_usage AS kc
WHERE
kc.table_schema = DATABASE() AND
kc.table_name = %s
ORDER BY kc.`ordinal_position`
"""
cursor.execute(name_query, [table_name])
for constraint, column, ref_table, ref_column in cursor.fetchall():
if constraint not in constraints:
constraints[constraint] = {
'columns': OrderedSet(),
'primary_key': False,
'unique': False,
'index': False,
'check': False,
'foreign_key': (ref_table, ref_column) if ref_column else None,
}
constraints[constraint]['columns'].add(column)
# Now get the constraint types
type_query = """
SELECT c.constraint_name, c.constraint_type
FROM information_schema.table_constraints AS c
WHERE
c.table_schema = DATABASE() AND
c.table_name = %s
"""
cursor.execute(type_query, [table_name])
for constraint, kind in cursor.fetchall():
if kind.lower() == "primary key":
constraints[constraint]['primary_key'] = True
constraints[constraint]['unique'] = True
elif kind.lower() == "unique":
constraints[constraint]['unique'] = True
# 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, type_ in [x[:5] + (x[10],) for x in cursor.fetchall()]:
if index not in constraints:
constraints[index] = {
'columns': OrderedSet(),
'primary_key': False,
'unique': False,
'check': False,
'foreign_key': None,
}
constraints[index]['index'] = True
constraints[index]['type'] = Index.suffix if type_ == 'BTREE' else type_.lower()
constraints[index]['columns'].add(column)
# Convert the sorted sets to lists
for constraint in constraints.values():
constraint['columns'] = list(constraint['columns'])
return constraints
|
2586e11aa9d8f341145577b609a2697bd9903658e67f3df2fe7f85adb032194b | """
MySQL database backend for Django.
Requires mysqlclient: https://pypi.org/project/mysqlclient/
"""
import re
from django.core.exceptions import ImproperlyConfigured
from django.db import utils
from django.db.backends import utils as backend_utils
from django.db.backends.base.base import BaseDatabaseWrapper
from django.utils.functional import cached_property
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 # isort:skip
from MySQLdb.converters import conversions # isort:skip
# Some of these import MySQLdb, so import them after checking if it's installed.
from .client import DatabaseClient # isort:skip
from .creation import DatabaseCreation # isort:skip
from .features import DatabaseFeatures # isort:skip
from .introspection import DatabaseIntrospection # isort:skip
from .operations import DatabaseOperations # isort:skip
from .schema import DatabaseSchemaEditor # isort:skip
from .validation import DatabaseValidation # isort:skip
version = Database.version_info
if version < (1, 3, 13):
raise ImproperlyConfigured('mysqlclient 1.3.13 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 = 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
)
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 utils.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 utils.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'
display_name = '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)',
'NullBooleanField': 'bool',
'OneToOneField': 'integer',
'PositiveIntegerField': 'integer UNSIGNED',
'PositiveSmallIntegerField': 'smallint UNSIGNED',
'SlugField': 'varchar(%(max_length)s)',
'SmallIntegerField': 'smallint',
'TextField': 'longtext',
'TimeField': 'time(6)',
'UUIDField': 'char(32)',
}
# For these columns, MySQL doesn't:
# - accept default values and implicitly treats these columns as nullable
# - support a database index
_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['db'] = settings_dict['NAME']
if settings_dict['PASSWORD']:
kwargs['passwd'] = 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
def get_new_connection(self, conn_params):
return Database.connect(**conn_params)
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))
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.
"""
self.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:
self.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
key_columns = self.introspection.get_key_columns(cursor, table_name)
for column_name, referenced_table_name, referenced_column_name in key_columns:
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 utils.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 mysql_server_info(self):
with self.temporary_connection() as cursor:
cursor.execute('SELECT VERSION()')
return cursor.fetchone()[0]
@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()
|
6acfeca07ffd42a0d955375d85b4dcaa168ca9a6ecde4c69d706f577a3a2e6cd | import uuid
from django.conf import settings
from django.db.backends.base.operations import BaseDatabaseOperations
from django.utils import timezone
from django.utils.duration import duration_microseconds
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),
}
cast_data_types = {
'AutoField': 'signed integer',
'BigAutoField': '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',
'PositiveIntegerField': 'unsigned integer',
'PositiveSmallIntegerField': 'unsigned 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.
# Note: WEEKDAY() returns 0-6, Monday=0.
return "DAYOFWEEK(%s)" % 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):
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):
if '+' in tzname:
return tzname[tzname.find('+'):]
elif '-' in tzname:
return tzname[tzname.find('-'):]
return tzname
def _convert_field_to_tz(self, field_name, tzname):
if 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):
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 date_interval_sql(self, timedelta):
return 'INTERVAL %s MICROSECOND' % duration_microseconds(timedelta)
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 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 random_function_sql(self):
return 'RAND()'
def sql_flush(self, style, tables, sequences, allow_cascade=False):
# NB: The generated SQL below is specific to MySQL
# 'TRUNCATE x;', 'TRUNCATE y;', 'TRUNCATE z;'... style SQL statements
# to clear all tables of all data
if tables:
sql = ['SET FOREIGN_KEY_CHECKS = 0;']
for table in tables:
sql.append('%s %s;' % (
style.SQL_KEYWORD('TRUNCATE'),
style.SQL_FIELD(self.quote_name(table)),
))
sql.append('SET FOREIGN_KEY_CHECKS = 1;')
sql.extend(self.sequence_reset_by_name_sql(style, sequences))
return sql
else:
return []
def validate_autopk_value(self, value):
# MySQLism: zero in AUTO_INCREMENT field does not work. Refs #17653.
if value == 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 str(value)
def max_name_length(self):
return 64
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 ('&', '|', '<<'):
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 in ['BooleanField', 'NullBooleanField']:
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}, lhs_params * 2 + rhs_params * 2
else:
return "TIMESTAMPDIFF(MICROSECOND, %s, %s)" % (rhs_sql, lhs_sql), rhs_params + lhs_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'
prefix = super().explain_query_prefix(format, **options)
if format:
prefix += ' FORMAT=%s' % format
if self.connection.features.needs_explain_extended and format is None:
# EXTENDED and FORMAT are mutually exclusive options.
prefix += ' EXTENDED'
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 5.6 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, ignore_conflicts=False):
return 'INSERT IGNORE INTO' if ignore_conflicts else super().insert_statement(ignore_conflicts)
|
0018735d4d66a393776e097b6ea3f0870cd947bb2ec2e3fb62cf11a1b9e06cac | 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"
# 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_rename_column = "ALTER TABLE %(table)s CHANGE %(old_column)s %(new_column)s %(type)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'
def quote_value(self, value):
self.connection.ensure_connection()
# 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):
return self._is_limited_data_type(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):
create_index = super()._field_should_be_indexed(model, field)
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
create_index and
field.get_internal_type() == 'ForeignKey' and
field.db_constraint):
return False
return not self._is_limited_data_type(field) and create_index
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.
http://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, [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)
|
a67deeb501c584f5fddd3f20d59f24f3f5374c352cb3a7c321e52068836da1b7 | import subprocess
import sys
from django.db.backends.base.creation import BaseDatabaseCreation
from .client import DatabaseClient
class DatabaseCreation(BaseDatabaseCreation):
def sql_table_creation_suffix(self):
suffix = []
test_settings = self.connection.settings_dict['TEST']
if test_settings['CHARSET']:
suffix.append('CHARACTER SET %s' % test_settings['CHARSET'])
if test_settings['COLLATION']:
suffix.append('COLLATE %s' % test_settings['COLLATION'])
return ' '.join(suffix)
def _execute_create_test_db(self, cursor, parameters, keepdb=False):
try:
super()._execute_create_test_db(cursor, parameters, keepdb)
except Exception as e:
if len(e.args) < 1 or e.args[0] != 1007:
# All errors except "database exists" (1007) cancel tests.
self.log('Got an error creating the test database: %s' % e)
sys.exit(2)
else:
raise e
def _clone_test_db(self, suffix, verbosity, keepdb=False):
source_database_name = self.connection.settings_dict['NAME']
target_database_name = self.get_test_db_clone_settings(suffix)['NAME']
test_db_params = {
'dbname': self.connection.ops.quote_name(target_database_name),
'suffix': self.sql_table_creation_suffix(),
}
with self._nodb_connection.cursor() as cursor:
try:
self._execute_create_test_db(cursor, test_db_params, keepdb)
except Exception:
if keepdb:
# If the database should be kept, skip everything else.
return
try:
if verbosity >= 1:
self.log('Destroying old test database for alias %s...' % (
self._get_database_display_str(verbosity, target_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)
self._clone_db(source_database_name, target_database_name)
def _clone_db(self, source_database_name, target_database_name):
dump_args = DatabaseClient.settings_to_cmd_args(self.connection.settings_dict)[1:]
dump_args[-1] = source_database_name
dump_cmd = ['mysqldump', '--routines', '--events'] + dump_args
load_cmd = DatabaseClient.settings_to_cmd_args(self.connection.settings_dict)
load_cmd[-1] = target_database_name
with subprocess.Popen(dump_cmd, stdout=subprocess.PIPE) as dump_proc:
with subprocess.Popen(load_cmd, stdin=dump_proc.stdout, stdout=subprocess.DEVNULL):
# Allow dump_proc to receive a SIGPIPE if the load process exits.
dump_proc.stdout.close()
|
3e0f3f8cd0fe6a8268993681057537849123ce907eacbb3a570a682a4398b908 | from django.db.backends.base.features import BaseDatabaseFeatures
class DummyDatabaseFeatures(BaseDatabaseFeatures):
supports_transactions = False
uses_savepoints = False
|
312d164f7bd36aea37935e0c40c2ea839fec04f71ac7b4cdcaf10a06a0136f42 | import operator
from django.db.backends.base.features import BaseDatabaseFeatures
from django.db.utils import InterfaceError
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
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
can_release_savepoints = True
supports_tablespaces = True
supports_transactions = True
can_introspect_autofield = True
can_introspect_ip_address_field = True
can_introspect_materialized_views = True
can_introspect_small_integer_field = True
can_distinct_on_fields = True
can_rollback_ddl = True
supports_combined_alters = True
nulls_order_largest = True
closed_cursor_error_class = InterfaceError
has_case_insensitive_like = False
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
supports_aggregate_filter_clause = True
supported_explain_formats = {'JSON', 'TEXT', 'XML', 'YAML'}
validates_explain_options = False # A query will error on invalid options.
@cached_property
def is_postgresql_9_6(self):
return self.connection.pg_version >= 90600
@cached_property
def is_postgresql_10(self):
return self.connection.pg_version >= 100000
has_brin_autosummarize = property(operator.attrgetter('is_postgresql_10'))
has_phraseto_tsquery = property(operator.attrgetter('is_postgresql_9_6'))
supports_table_partitions = property(operator.attrgetter('is_postgresql_10'))
|
db844c2980cabbfa778efedfd04a2c2bd1d71d4051f68d706985a573a75d7648 | from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo, TableInfo,
)
from django.db.models.indexes 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',
}
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'
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 {} 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)
""".format('c.relispartition' if self.connection.features.supports_table_partitions else 'FALSE'))
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
FROM pg_attribute a
LEFT JOIN pg_attrdef ad ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum
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
JOIN pg_namespace n ON n.oid = tbl.relnamespace
WHERE s.relkind = 'S'
AND d.deptype in ('a', 'n')
AND n.nspname = 'public'
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 relationships to the given table.
"""
cursor.execute("""
SELECT c2.relname, a1.attname, 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'
""", [table_name])
return {row[1]: (row[2], row[0]) for row in cursor.fetchall()}
def get_key_columns(self, cursor, table_name):
cursor.execute("""
SELECT kcu.column_name, ccu.table_name AS referenced_table, ccu.column_name AS referenced_column
FROM information_schema.constraint_column_usage ccu
LEFT JOIN information_schema.key_column_usage kcu
ON ccu.constraint_catalog = kcu.constraint_catalog
AND ccu.constraint_schema = kcu.constraint_schema
AND ccu.constraint_name = kcu.constraint_name
LEFT JOIN information_schema.table_constraints tc
ON ccu.constraint_catalog = tc.constraint_catalog
AND ccu.constraint_schema = tc.constraint_schema
AND ccu.constraint_name = tc.constraint_name
WHERE kcu.table_name = %s AND tc.constraint_type = 'FOREIGN KEY'
""", [table_name])
return 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
JOIN pg_namespace AS ns ON cl.relnamespace = ns.oid
WHERE ns.nspname = %s AND cl.relname = %s
""", ["public", 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 'btree' 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
) s2
GROUP BY indexname, indisunique, indisprimary, amname, exprdef, attoptions;
""", [table_name])
for index, columns, unique, primary, orders, type_, definition, options in cursor.fetchall():
if index not in constraints:
basic_index = type_ == 'btree' and 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
|
3c640b4402e61cc793d2ecc3866298f0a84cf772b8c63723bf2fb33ead794b50 | """
PostgreSQL database backend for Django.
Requires psycopg 2: http://initd.org/projects/psycopg2
"""
import threading
import warnings
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import connections
from django.db.backends.base.base import BaseDatabaseWrapper
from django.db.backends.utils import (
CursorDebugWrapper as BaseCursorDebugWrapper,
)
from django.db.utils import DatabaseError as WrappedDatabaseError
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, 5, 4):
raise ImproperlyConfigured("psycopg2_version 2.5.4 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 isort:skip
from .creation import DatabaseCreation # NOQA isort:skip
from .features import DatabaseFeatures # NOQA isort:skip
from .introspection import DatabaseIntrospection # NOQA isort:skip
from .operations import DatabaseOperations # NOQA isort:skip
from .schema import DatabaseSchemaEditor # NOQA isort:skip
from .utils import utc_tzinfo_factory # NOQA isort:skip
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',
'NullBooleanField': 'boolean',
'OneToOneField': 'integer',
'PositiveIntegerField': 'integer',
'PositiveSmallIntegerField': 'smallint',
'SlugField': 'varchar(%(max_length)s)',
'SmallIntegerField': 'smallint',
'TextField': 'text',
'TimeField': 'time',
'UUIDField': 'uuid',
}
data_type_check_constraints = {
'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'] == '':
raise ImproperlyConfigured(
"settings.DATABASES is improperly configured. "
"Please supply the NAME 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 = {
'database': settings_dict['NAME'] or 'postgres',
**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
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)
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()
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 = utc_tzinfo_factory if settings.USE_TZ else None
return cursor
def chunked_cursor(self):
self._named_cursor_idx += 1
return self._cursor(
name='_django_curs_%d_%d' % (
# Avoid reusing name in other threads
threading.current_thread().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.
"""
self.cursor().execute('SET CONSTRAINTS ALL IMMEDIATE')
self.cursor().execute('SET CONSTRAINTS ALL DEFERRED')
def is_usable(self):
try:
# Use a psycopg cursor directly, bypassing Django's utilities.
self.connection.cursor().execute("SELECT 1")
except Database.Error:
return False
else:
return True
@property
def _nodb_connection(self):
nodb_connection = super()._nodb_connection
try:
nodb_connection.ensure_connection()
except (Database.DatabaseError, WrappedDatabaseError):
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':
return self.__class__(
{**self.settings_dict, 'NAME': connection.settings_dict['NAME']},
alias=self.alias,
)
return nodb_connection
@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)
|
b500e4805177a86fe609592daf8cf27e2950714a9d691222cd333b9342d5a890 | from psycopg2.extras import Inet
from django.conf import settings
from django.db import NotSupportedError
from django.db.backends.base.operations import BaseDatabaseOperations
class DatabaseOperations(BaseDatabaseOperations):
cast_char_field_without_max_length = 'varchar'
explain_prefix = 'EXPLAIN'
cast_data_types = {
'AutoField': 'integer',
'BigAutoField': 'bigint',
}
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_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):
# 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):
if '+' in tzname:
return tzname.replace('+', '-')
elif '-' in tzname:
return tzname.replace('-', '+')
return tzname
def _convert_field_to_tz(self, field_name, tzname):
if 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):
return "DATE_TRUNC('%s', %s)::time" % (lookup_type, field_name)
def deferrable_sql(self):
return " DEFERRABLE INITIALLY DEFERRED"
def fetch_returned_insert_ids(self, cursor):
"""
Given a cursor object that has just performed an INSERT...RETURNING
statement into a table that has an auto-incrementing ID, return the
list of newly created IDs.
"""
return [item[0] for item in 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, sequences, allow_cascade=False):
if tables:
# Perform a single SQL 'TRUNCATE x, y, z...;' statement. It allows
# us to truncate tables referenced by a foreign key in any other
# table.
tables_sql = ', '.join(
style.SQL_FIELD(self.quote_name(table)) for table in tables)
if allow_cascade:
sql = ['%s %s %s;' % (
style.SQL_KEYWORD('TRUNCATE'),
tables_sql,
style.SQL_KEYWORD('CASCADE'),
)]
else:
sql = ['%s %s;' % (
style.SQL_KEYWORD('TRUNCATE'),
tables_sql,
)]
sql.extend(self.sequence_reset_by_name_sql(style, sequences))
return sql
else:
return []
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.
for f in model._meta.many_to_many:
if not f.remote_field.through:
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(f.m2m_db_table())),
style.SQL_FIELD('id'),
style.SQL_FIELD(qn('id')),
style.SQL_FIELD(qn('id')),
style.SQL_KEYWORD('IS NOT'),
style.SQL_KEYWORD('FROM'),
style.SQL_TABLE(qn(f.m2m_db_table()))
)
)
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):
# http://initd.org/psycopg/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_id(self):
return "RETURNING %s", ()
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_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
return "(interval '1 day' * (%s - %s))" % (lhs_sql, rhs_sql), lhs_params + rhs_params
return super().subtract_temporals(internal_type, lhs, rhs)
def window_frame_range_start_end(self, start=None, end=None):
start_, end_ = super().window_frame_range_start_end(start, end)
if (start and start < 0) or (end and end > 0):
raise NotSupportedError(
'PostgreSQL only supports UNBOUNDED together with PRECEDING '
'and FOLLOWING.'
)
return start_, end_
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 ignore_conflicts_suffix_sql(self, ignore_conflicts=None):
return 'ON CONFLICT DO NOTHING' if ignore_conflicts else super().ignore_conflicts_suffix_sql(ignore_conflicts)
|
6a65c7c66ebaf8ff34f635798a0a87289309a2347ea1280fd407b34034e53b05 | import psycopg2
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.backends.ddl_references import IndexColumns
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
sql_create_sequence = "CREATE SEQUENCE %(sequence)s"
sql_delete_sequence = "DROP SEQUENCE IF EXISTS %(sequence)s CASCADE"
sql_set_sequence_max = "SELECT setval('%(sequence)s', MAX(%(column)s)) FROM %(table)s"
sql_set_sequence_owner = 'ALTER SEQUENCE %(sequence)s OWNED BY %(table)s.%(column)s'
sql_create_index = "CREATE INDEX %(name)s ON %(table)s%(using)s (%(columns)s)%(extra)s%(condition)s"
sql_delete_index = "DROP INDEX IF EXISTS %(name)s"
sql_create_column_inline_fk = 'REFERENCES %(to_table)s(%(to_column)s)%(deferrable)s'
# Setting the constraint to IMMEDIATE runs any deferred checks to allow
# dropping it in the same transaction.
sql_delete_fk = "SET CONSTRAINTS %(name)s IMMEDIATE; ALTER TABLE %(table)s DROP CONSTRAINT %(name)s"
sql_delete_procedure = 'DROP FUNCTION %(procedure)s(%(param_types)s)'
def quote_value(self, value):
if isinstance(value, str):
value = value.replace('%', '%%')
# getquoted() returns a quoted bytestring of the adapted value.
return psycopg2.extensions.adapt(value).getquoted().decode()
def _field_indexes_sql(self, model, field):
output = super()._field_indexes_sql(model, field)
like_index_statement = self._create_like_index_sql(model, field)
if like_index_statement is not None:
output.append(like_index_statement)
return output
def _field_data_type(self, field):
if field.is_relation:
return field.rel_db_type(self.connection)
return self.connection.data_types[field.get_internal_type()]
def _create_like_index_sql(self, model, field):
"""
Return the statement to create an index with varchar operator pattern
when the column type is 'varchar' or 'text', otherwise return None.
"""
db_type = field.db_type(connection=self.connection)
if db_type is not None and (field.db_index or field.unique):
# Fields with database column types of `varchar` and `text` need
# a second index that specifies their operator class, which is
# needed when performing correct LIKE queries outside the
# C locale. See #12234.
#
# The same doesn't apply to array fields such as varchar[size]
# and text[size], so skip them.
if '[' in db_type:
return None
if db_type.startswith('varchar'):
return self._create_index_sql(model, [field], suffix='_like', opclasses=['varchar_pattern_ops'])
elif db_type.startswith('text'):
return self._create_index_sql(model, [field], suffix='_like', opclasses=['text_pattern_ops'])
return None
def _alter_column_type_sql(self, model, old_field, new_field, new_type):
self.sql_alter_column_type = 'ALTER COLUMN %(column)s TYPE %(type)s'
# Cast when data type changed.
if self._field_data_type(old_field) != self._field_data_type(new_field):
self.sql_alter_column_type += ' USING %(column)s::%(type)s'
# Make ALTER TYPE with SERIAL make sense.
table = model._meta.db_table
if new_type.lower() in ("serial", "bigserial"):
column = new_field.column
sequence_name = "%s_%s_seq" % (table, column)
col_type = "integer" if new_type.lower() == "serial" else "bigint"
return (
(
self.sql_alter_column_type % {
"column": self.quote_name(column),
"type": col_type,
},
[],
),
[
(
self.sql_delete_sequence % {
"sequence": self.quote_name(sequence_name),
},
[],
),
(
self.sql_create_sequence % {
"sequence": self.quote_name(sequence_name),
},
[],
),
(
self.sql_alter_column % {
"table": self.quote_name(table),
"changes": self.sql_alter_column_default % {
"column": self.quote_name(column),
"default": "nextval('%s')" % self.quote_name(sequence_name),
}
},
[],
),
(
self.sql_set_sequence_max % {
"table": self.quote_name(table),
"column": self.quote_name(column),
"sequence": self.quote_name(sequence_name),
},
[],
),
(
self.sql_set_sequence_owner % {
'table': self.quote_name(table),
'column': self.quote_name(column),
'sequence': self.quote_name(sequence_name),
},
[],
),
],
)
else:
return super()._alter_column_type_sql(model, old_field, new_field, new_type)
def _alter_field(self, model, old_field, new_field, old_type, new_type,
old_db_params, new_db_params, strict=False):
# Drop indexes on varchar/text/citext columns that are changing to a
# different type.
if (old_field.db_index or old_field.unique) and (
(old_type.startswith('varchar') and not new_type.startswith('varchar')) or
(old_type.startswith('text') and not new_type.startswith('text')) or
(old_type.startswith('citext') and not new_type.startswith('citext'))
):
index_name = self._create_index_name(model._meta.db_table, [old_field.column], suffix='_like')
self.execute(self._delete_index_sql(model, index_name))
super()._alter_field(
model, old_field, new_field, old_type, new_type, old_db_params,
new_db_params, strict,
)
# Added an index? Create any PostgreSQL-specific indexes.
if ((not (old_field.db_index or old_field.unique) and new_field.db_index) or
(not old_field.unique and new_field.unique)):
like_index_statement = self._create_like_index_sql(model, new_field)
if like_index_statement is not None:
self.execute(like_index_statement)
# Removed an index? Drop any PostgreSQL-specific indexes.
if old_field.unique and not (new_field.db_index or new_field.unique):
index_to_remove = self._create_index_name(model._meta.db_table, [old_field.column], suffix='_like')
self.execute(self._delete_index_sql(model, index_to_remove))
def _index_columns(self, table, columns, col_suffixes, opclasses):
if opclasses:
return IndexColumns(table, columns, self.quote_name, col_suffixes=col_suffixes, opclasses=opclasses)
return super()._index_columns(table, columns, col_suffixes, opclasses)
|
939a5a6c53c0b2e2eb47cfb33f5ece1ffb56f48a87fada026f71492fee8871c1 | import os
import signal
import subprocess
from django.db.backends.base.client import BaseDatabaseClient
class DatabaseClient(BaseDatabaseClient):
executable_name = 'psql'
@classmethod
def runshell_db(cls, conn_params):
args = [cls.executable_name]
host = conn_params.get('host', '')
port = conn_params.get('port', '')
dbname = conn_params.get('database', '')
user = conn_params.get('user', '')
passwd = conn_params.get('password', '')
sslmode = conn_params.get('sslmode', '')
sslrootcert = conn_params.get('sslrootcert', '')
sslcert = conn_params.get('sslcert', '')
sslkey = conn_params.get('sslkey', '')
if user:
args += ['-U', user]
if host:
args += ['-h', host]
if port:
args += ['-p', str(port)]
args += [dbname]
sigint_handler = signal.getsignal(signal.SIGINT)
subprocess_env = os.environ.copy()
if passwd:
subprocess_env['PGPASSWORD'] = str(passwd)
if sslmode:
subprocess_env['PGSSLMODE'] = str(sslmode)
if sslrootcert:
subprocess_env['PGSSLROOTCERT'] = str(sslrootcert)
if sslcert:
subprocess_env['PGSSLCERT'] = str(sslcert)
if sslkey:
subprocess_env['PGSSLKEY'] = str(sslkey)
try:
# Allow SIGINT to pass to psql to abort queries.
signal.signal(signal.SIGINT, signal.SIG_IGN)
subprocess.run(args, check=True, env=subprocess_env)
finally:
# Restore the original SIGINT handler.
signal.signal(signal.SIGINT, sigint_handler)
def runshell(self):
DatabaseClient.runshell_db(self.connection.get_connection_params())
|
6b5d29fb1327215cb2d72d2f00593d33a0b12ea52285c76c5cd4c02467517af3 | import sys
from psycopg2 import errorcodes
from django.db.backends.base.creation import BaseDatabaseCreation
from django.db.backends.utils import strip_quotes
class DatabaseCreation(BaseDatabaseCreation):
def _quote_name(self, name):
return self.connection.ops.quote_name(name)
def _get_database_create_suffix(self, encoding=None, template=None):
suffix = ""
if encoding:
suffix += " ENCODING '{}'".format(encoding)
if template:
suffix += " TEMPLATE {}".format(self._quote_name(template))
return suffix and "WITH" + suffix
def sql_table_creation_suffix(self):
test_settings = self.connection.settings_dict['TEST']
assert test_settings['COLLATION'] is None, (
"PostgreSQL does not support collation setting at database creation time."
)
return self._get_database_create_suffix(
encoding=test_settings['CHARSET'],
template=test_settings.get('TEMPLATE'),
)
def _database_exists(self, cursor, database_name):
cursor.execute('SELECT 1 FROM pg_catalog.pg_database WHERE datname = %s', [strip_quotes(database_name)])
return cursor.fetchone() is not None
def _execute_create_test_db(self, cursor, parameters, keepdb=False):
try:
if keepdb and self._database_exists(cursor, parameters['dbname']):
# If the database should be kept and it already exists, don't
# try to create a new one.
return
super()._execute_create_test_db(cursor, parameters, keepdb)
except Exception as e:
if getattr(e.__cause__, 'pgcode', '') != errorcodes.DUPLICATE_DATABASE:
# All errors except "database already exists" cancel tests.
self.log('Got an error creating the test database: %s' % e)
sys.exit(2)
elif not keepdb:
# If the database should be kept, ignore "database already
# exists".
raise e
def _clone_test_db(self, suffix, verbosity, keepdb=False):
# CREATE DATABASE ... WITH TEMPLATE ... requires closing connections
# to the template database.
self.connection.close()
source_database_name = self.connection.settings_dict['NAME']
target_database_name = self.get_test_db_clone_settings(suffix)['NAME']
test_db_params = {
'dbname': self._quote_name(target_database_name),
'suffix': self._get_database_create_suffix(template=source_database_name),
}
with self._nodb_connection.cursor() as cursor:
try:
self._execute_create_test_db(cursor, test_db_params, keepdb)
except Exception:
try:
if verbosity >= 1:
self.log('Destroying old test database for alias %s...' % (
self._get_database_display_str(verbosity, target_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 cloning the test database: %s' % e)
sys.exit(2)
|
e56b00a713390ca52881b97819f439b386e1e1ab01777a7452a744b3c886976b | from django.db.backends.base.features import BaseDatabaseFeatures
from .base import Database
class DatabaseFeatures(BaseDatabaseFeatures):
# SQLite can read from a cursor since SQLite 3.6.5, subject to the caveat
# that statements within a connection aren't isolated from each other. See
# https://sqlite.org/isolation.html.
can_use_chunked_reads = True
test_db_allows_multiple_connections = False
supports_unspecified_pk = True
supports_timezones = False
max_query_params = 999
supports_mixed_date_datetime_comparisons = False
can_introspect_autofield = True
can_introspect_decimal_field = False
can_introspect_duration_field = False
can_introspect_positive_integer_field = True
can_introspect_small_integer_field = True
introspected_big_auto_field_type = 'AutoField'
supports_transactions = True
atomic_transactions = False
can_rollback_ddl = True
supports_atomic_references_rename = Database.sqlite_version_info >= (3, 26, 0)
can_create_inline_fk = False
supports_paramstyle_pyformat = False
supports_sequence_reset = False
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
# 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)
|
b0ed1e67aa0a44b521dce7082face09760dcb56edc2ff0e05adbb285f81544dd | import re
from collections import namedtuple
import sqlparse
from django.db.backends.base.introspection import (
BaseDatabaseIntrospection, FieldInfo as BaseFieldInfo, TableInfo,
)
from django.db.models.indexes import Index
FieldInfo = namedtuple('FieldInfo', BaseFieldInfo._fields + ('pk',))
field_size_re = 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.group(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',
'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'}:
# No support for BigAutoField as SQLite treats all integer primary
# keys as signed 64-bit integers.
return 'AutoField'
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))
return [
FieldInfo(
name, data_type, None, get_field_size(data_type), None, None,
not notnull, default, pk == 1,
)
for cid, name, data_type, notnull, default, pk in cursor.fetchall()
]
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 {field_name: (field_name_other_table, other_table)}
representing all relationships to the given table.
"""
# Dictionary of relations to return
relations = {}
# Schema for this table
cursor.execute(
"SELECT sql, type FROM sqlite_master "
"WHERE tbl_name = %s AND type IN ('table', 'view')",
[table_name]
)
create_sql, table_type = cursor.fetchone()
if table_type == 'view':
# It might be a view, then no results will be returned
return relations
results = create_sql[create_sql.index('(') + 1:create_sql.rindex(')')]
# Walk through and look for references to other tables. SQLite doesn't
# really have enforced references, but since it echoes out the SQL used
# to create the table we can look for REFERENCES statements used there.
for field_desc in results.split(','):
field_desc = field_desc.strip()
if field_desc.startswith("UNIQUE"):
continue
m = re.search(r'references (\S*) ?\(["|]?(.*)["|]?\)', field_desc, re.I)
if not m:
continue
table, column = [s.strip('"') for s in m.groups()]
if field_desc.startswith("FOREIGN KEY"):
# Find name of the target FK field
m = re.match(r'FOREIGN KEY\s*\(([^\)]*)\).*', field_desc, re.I)
field_name = m.groups()[0].strip('"')
else:
field_name = field_desc.split()[0].strip('"')
cursor.execute("SELECT sql FROM sqlite_master WHERE tbl_name = %s", [table])
result = cursor.fetchall()[0]
other_table_results = result[0].strip()
li, ri = other_table_results.index('('), other_table_results.rindex(')')
other_table_results = other_table_results[li + 1:ri]
for other_desc in other_table_results.split(','):
other_desc = other_desc.strip()
if other_desc.startswith('UNIQUE'):
continue
other_name = other_desc.split(' ', 1)[0].strip('"')
if other_name == column:
relations[field_name] = (other_name, table)
break
return relations
def get_key_columns(self, cursor, table_name):
"""
Return a list of (column_name, referenced_table_name, referenced_column_name)
for all key columns in given table.
"""
key_columns = []
# Schema for this table
cursor.execute("SELECT sql FROM sqlite_master WHERE tbl_name = %s AND type = %s", [table_name, "table"])
results = cursor.fetchone()[0].strip()
results = results[results.index('(') + 1:results.rindex(')')]
# Walk through and look for references to other tables. SQLite doesn't
# really have enforced references, but since it echoes out the SQL used
# to create the table we can look for REFERENCES statements used there.
for field_index, field_desc in enumerate(results.split(',')):
field_desc = field_desc.strip()
if field_desc.startswith("UNIQUE"):
continue
m = re.search(r'"(.*)".*references (.*) \(["|](.*)["|]\)', field_desc, re.I)
if not m:
continue
# This will append (column_name, referenced_table_name, referenced_column_name) to key_columns
key_columns.append(tuple(s.strip('"') for s in m.groups()))
return key_columns
def get_primary_key_column(self, cursor, table_name):
"""Return the column name of the primary key for the given table."""
# Don't use PRAGMA because that causes issues with some transactions
cursor.execute(
"SELECT sql, type FROM sqlite_master "
"WHERE tbl_name = %s AND type IN ('table', 'view')",
[table_name]
)
row = cursor.fetchone()
if row is None:
raise ValueError("Table %s does not exist" % table_name)
create_sql, table_type = row
if table_type == 'view':
# Views don't have a primary key.
return None
fields_sql = create_sql[create_sql.index('(') + 1:create_sql.rindex(')')]
for field_desc in fields_sql.split(','):
field_desc = field_desc.strip()
m = re.match(r'(?:(?:["`\[])(.*)(?:["`\]])|(\w+)).*PRIMARY KEY.*', field_desc)
if m:
return m.group(1) if m.group(1) else m.group(2)
return None
def _get_foreign_key_constraints(self, cursor, table_name):
constraints = {}
cursor.execute('PRAGMA foreign_key_list(%s)' % self.connection.ops.quote_name(table_name))
for row in cursor.fetchall():
# Remaining on_update/on_delete/match values are of no interest.
id_, _, table, from_, to = row[:5]
constraints['fk_%d' % id_] = {
'columns': [from_],
'primary_key': False,
'unique': False,
'foreign_key': (table, to),
'check': False,
'index': False,
}
return constraints
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'] and not constraints[index]['unique']:
# SQLite doesn't support any index type other than b-tree
constraints[index]['type'] = Index.suffix
order_info = sql.split('(')[-1].split(')')[0].split(',')
orders = ['DESC' if info.endswith('DESC') else 'ASC' for info in order_info]
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,
}
constraints.update(self._get_foreign_key_constraints(cursor, table_name))
return constraints
|
29a01a8c61ae767eb32ef9e20600900e6d3d6affc89071aacdf549a048cfd4fc | """
SQLite backend for the sqlite3 module in the standard library.
"""
import datetime
import decimal
import functools
import hashlib
import math
import operator
import re
import statistics
import warnings
from itertools import chain
from sqlite3 import dbapi2 as Database
import pytz
from django.core.exceptions import ImproperlyConfigured
from django.db import utils
from django.db.backends import utils as backend_utils
from django.db.backends.base.base import BaseDatabaseWrapper
from django.utils import timezone
from django.utils.dateparse import parse_datetime, parse_time
from django.utils.duration import duration_microseconds
from .client import DatabaseClient # isort:skip
from .creation import DatabaseCreation # isort:skip
from .features import DatabaseFeatures # isort:skip
from .introspection import DatabaseIntrospection # isort:skip
from .operations import DatabaseOperations # isort:skip
from .schema import DatabaseSchemaEditor # isort:skip
def decoder(conv_func):
"""
Convert bytestrings from Python's sqlite3 interface to a regular string.
"""
return lambda s: conv_func(s.decode())
def none_guard(func):
"""
Decorator that returns None if any of the arguments to the decorated
function are None. Many SQL functions return NULL if any of their arguments
are NULL. This decorator simplifies the implementation of this for the
custom functions registered below.
"""
@functools.wraps(func)
def wrapper(*args, **kwargs):
return None if None in args else func(*args, **kwargs)
return wrapper
def list_aggregate(function):
"""
Return an aggregate class that accumulates values in a list and applies
the provided function to the data.
"""
return type('ListAggregate', (list,), {'finalize': function, 'step': list.append})
def check_sqlite_version():
if Database.sqlite_version_info < (3, 8, 3):
raise ImproperlyConfigured('SQLite 3.8.3 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_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)',
'NullBooleanField': 'bool',
'OneToOneField': 'integer',
'PositiveIntegerField': 'integer unsigned',
'PositiveSmallIntegerField': 'smallint unsigned',
'SlugField': 'varchar(%(max_length)s)',
'SmallIntegerField': 'smallint',
'TextField': 'text',
'TimeField': 'time',
'UUIDField': 'char(32)',
}
data_type_check_constraints = {
'PositiveIntegerField': '"%(column)s" >= 0',
'PositiveSmallIntegerField': '"%(column)s" >= 0',
}
data_types_suffix = {
'AutoField': 'AUTOINCREMENT',
'BigAutoField': '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
def get_new_connection(self, conn_params):
conn = Database.connect(**conn_params)
conn.create_function("django_date_extract", 2, _sqlite_datetime_extract)
conn.create_function("django_date_trunc", 2, _sqlite_date_trunc)
conn.create_function('django_datetime_cast_date', 3, _sqlite_datetime_cast_date)
conn.create_function('django_datetime_cast_time', 3, _sqlite_datetime_cast_time)
conn.create_function('django_datetime_extract', 4, _sqlite_datetime_extract)
conn.create_function('django_datetime_trunc', 4, _sqlite_datetime_trunc)
conn.create_function("django_time_extract", 2, _sqlite_time_extract)
conn.create_function("django_time_trunc", 2, _sqlite_time_trunc)
conn.create_function("django_time_diff", 2, _sqlite_time_diff)
conn.create_function("django_timestamp_diff", 2, _sqlite_timestamp_diff)
conn.create_function("django_format_dtdelta", 3, _sqlite_format_dtdelta)
conn.create_function('regexp', 2, _sqlite_regexp)
conn.create_function('ACOS', 1, none_guard(math.acos))
conn.create_function('ASIN', 1, none_guard(math.asin))
conn.create_function('ATAN', 1, none_guard(math.atan))
conn.create_function('ATAN2', 2, none_guard(math.atan2))
conn.create_function('CEILING', 1, none_guard(math.ceil))
conn.create_function('COS', 1, none_guard(math.cos))
conn.create_function('COT', 1, none_guard(lambda x: 1 / math.tan(x)))
conn.create_function('DEGREES', 1, none_guard(math.degrees))
conn.create_function('EXP', 1, none_guard(math.exp))
conn.create_function('FLOOR', 1, none_guard(math.floor))
conn.create_function('LN', 1, none_guard(math.log))
conn.create_function('LOG', 2, none_guard(lambda x, y: math.log(y, x)))
conn.create_function('LPAD', 3, _sqlite_lpad)
conn.create_function('MD5', 1, none_guard(lambda x: hashlib.md5(x.encode()).hexdigest()))
conn.create_function('MOD', 2, none_guard(math.fmod))
conn.create_function('PI', 0, lambda: math.pi)
conn.create_function('POWER', 2, none_guard(operator.pow))
conn.create_function('RADIANS', 1, none_guard(math.radians))
conn.create_function('REPEAT', 2, none_guard(operator.mul))
conn.create_function('REVERSE', 1, none_guard(lambda x: x[::-1]))
conn.create_function('RPAD', 3, _sqlite_rpad)
conn.create_function('SHA1', 1, none_guard(lambda x: hashlib.sha1(x.encode()).hexdigest()))
conn.create_function('SHA224', 1, none_guard(lambda x: hashlib.sha224(x.encode()).hexdigest()))
conn.create_function('SHA256', 1, none_guard(lambda x: hashlib.sha256(x.encode()).hexdigest()))
conn.create_function('SHA384', 1, none_guard(lambda x: hashlib.sha384(x.encode()).hexdigest()))
conn.create_function('SHA512', 1, none_guard(lambda x: hashlib.sha512(x.encode()).hexdigest()))
conn.create_function('SIGN', 1, none_guard(lambda x: (x > 0) - (x < 0)))
conn.create_function('SIN', 1, none_guard(math.sin))
conn.create_function('SQRT', 1, none_guard(math.sqrt))
conn.create_function('TAN', 1, none_guard(math.tan))
conn.create_aggregate('STDDEV_POP', 1, list_aggregate(statistics.pstdev))
conn.create_aggregate('STDDEV_SAMP', 1, list_aggregate(statistics.stdev))
conn.create_aggregate('VAR_POP', 1, list_aggregate(statistics.pvariance))
conn.create_aggregate('VAR_SAMP', 1, list_aggregate(statistics.variance))
conn.execute('PRAGMA foreign_keys = ON')
return conn
def init_connection_state(self):
pass
def create_cursor(self, name=None):
return self.connection.cursor(factory=SQLiteCursorWrapper)
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):
self.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 = self.cursor().execute('PRAGMA foreign_key_check').fetchall()
else:
violations = chain.from_iterable(
cursor.execute('PRAGMA foreign_key_check(%s)' % 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)' % 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' % (
primary_key_column_name, column_name, table_name
),
(rowid,),
).fetchone()
raise utils.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
key_columns = self.introspection.get_key_columns(cursor, table_name)
for column_name, referenced_table_name, referenced_column_name in key_columns:
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 utils.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 = 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('%%', '%')
def _sqlite_datetime_parse(dt, tzname=None, conn_tzname=None):
if dt is None:
return None
try:
dt = backend_utils.typecast_timestamp(dt)
except (TypeError, ValueError):
return None
if conn_tzname:
dt = dt.replace(tzinfo=pytz.timezone(conn_tzname))
if tzname is not None and tzname != conn_tzname:
sign_index = tzname.find('+') + tzname.find('-') + 1
if sign_index > -1:
sign = tzname[sign_index]
tzname, offset = tzname.split(sign)
if offset:
hours, minutes = offset.split(':')
offset_delta = datetime.timedelta(hours=int(hours), minutes=int(minutes))
dt += offset_delta if sign == '+' else -offset_delta
dt = timezone.localtime(dt, pytz.timezone(tzname))
return dt
def _sqlite_date_trunc(lookup_type, dt):
dt = _sqlite_datetime_parse(dt)
if dt is None:
return None
if lookup_type == 'year':
return "%i-01-01" % dt.year
elif lookup_type == 'quarter':
month_in_quarter = dt.month - (dt.month - 1) % 3
return '%i-%02i-01' % (dt.year, month_in_quarter)
elif lookup_type == 'month':
return "%i-%02i-01" % (dt.year, dt.month)
elif lookup_type == 'week':
dt = dt - datetime.timedelta(days=dt.weekday())
return "%i-%02i-%02i" % (dt.year, dt.month, dt.day)
elif lookup_type == 'day':
return "%i-%02i-%02i" % (dt.year, dt.month, dt.day)
def _sqlite_time_trunc(lookup_type, dt):
if dt is None:
return None
try:
dt = backend_utils.typecast_time(dt)
except (ValueError, TypeError):
return None
if lookup_type == 'hour':
return "%02i:00:00" % dt.hour
elif lookup_type == 'minute':
return "%02i:%02i:00" % (dt.hour, dt.minute)
elif lookup_type == 'second':
return "%02i:%02i:%02i" % (dt.hour, dt.minute, dt.second)
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 == 'week':
return dt.isocalendar()[1]
elif lookup_type == 'quarter':
return math.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 "%i-01-01 00:00:00" % dt.year
elif lookup_type == 'quarter':
month_in_quarter = dt.month - (dt.month - 1) % 3
return '%i-%02i-01 00:00:00' % (dt.year, month_in_quarter)
elif lookup_type == 'month':
return "%i-%02i-01 00:00:00" % (dt.year, dt.month)
elif lookup_type == 'week':
dt = dt - datetime.timedelta(days=dt.weekday())
return "%i-%02i-%02i 00:00:00" % (dt.year, dt.month, dt.day)
elif lookup_type == 'day':
return "%i-%02i-%02i 00:00:00" % (dt.year, dt.month, dt.day)
elif lookup_type == 'hour':
return "%i-%02i-%02i %02i:00:00" % (dt.year, dt.month, dt.day, dt.hour)
elif lookup_type == 'minute':
return "%i-%02i-%02i %02i:%02i:00" % (dt.year, dt.month, dt.day, dt.hour, dt.minute)
elif lookup_type == 'second':
return "%i-%02i-%02i %02i:%02i:%02i" % (dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second)
def _sqlite_time_extract(lookup_type, dt):
if dt is None:
return None
try:
dt = backend_utils.typecast_time(dt)
except (ValueError, TypeError):
return None
return getattr(dt, lookup_type)
@none_guard
def _sqlite_format_dtdelta(conn, lhs, rhs):
"""
LHS and RHS can be either:
- An integer number of microseconds
- A string representing a datetime
"""
try:
real_lhs = datetime.timedelta(0, 0, lhs) if isinstance(lhs, int) else backend_utils.typecast_timestamp(lhs)
real_rhs = datetime.timedelta(0, 0, rhs) if isinstance(rhs, int) else backend_utils.typecast_timestamp(rhs)
if conn.strip() == '+':
out = real_lhs + real_rhs
else:
out = real_lhs - real_rhs
except (ValueError, TypeError):
return None
# 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]"
return str(out)
@none_guard
def _sqlite_time_diff(lhs, rhs):
left = backend_utils.typecast_time(lhs)
right = backend_utils.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)
)
@none_guard
def _sqlite_timestamp_diff(lhs, rhs):
left = backend_utils.typecast_timestamp(lhs)
right = backend_utils.typecast_timestamp(rhs)
return duration_microseconds(left - right)
@none_guard
def _sqlite_regexp(re_pattern, re_string):
return bool(re.search(re_pattern, str(re_string)))
@none_guard
def _sqlite_lpad(text, length, fill_text):
if len(text) >= length:
return text[:length]
return (fill_text * length)[:length - len(text)] + text
@none_guard
def _sqlite_rpad(text, length, fill_text):
return (text + fill_text * length)[:length]
|
b6721e9be464e1eca00ae09bc0297be1f05980179aad3d12f82c42f9c6ac29c9 | 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 utils
from django.db.backends.base.operations import BaseDatabaseOperations
from django.db.models import aggregates, fields
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.duration import duration_microseconds
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'
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 = (fields.DateField, fields.DateTimeField, fields.TimeField)
bad_aggregates = (aggregates.Sum, aggregates.Avg, aggregates.Variance, aggregates.StdDev)
if isinstance(expression, bad_aggregates):
for expr in expression.get_source_expressions():
try:
output_field = expr.output_field
except FieldError:
# Not every subexpression has an output_field which is fine
# to ignore.
pass
else:
if isinstance(output_field, bad_fields):
raise utils.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, aggregates.Aggregate) and len(expression.source_expressions) > 1:
raise utils.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 date_interval_sql(self, timedelta):
return str(duration_microseconds(timedelta))
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):
return "django_date_trunc('%s', %s)" % (lookup_type.lower(), field_name)
def time_trunc_sql(self, lookup_type, field_name):
return "django_time_trunc('%s', %s)" % (lookup_type.lower(), field_name)
def _convert_tznames_to_sql(self, tzname):
if 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, sequences, 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))
# Note: No requirement for reset of auto-incremented indices (cf. other
# sql_flush() implementations). Just return SQL at this point
return ['%s %s %s;' % (
style.SQL_KEYWORD('DELETE'),
style.SQL_KEYWORD('FROM'),
style.SQL_FIELD(self.quote_name(table))
) for table in tables]
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 in ('NullBooleanField', '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):
return " UNION ALL ".join(
"SELECT %s" % ", ".join(row)
for row in placeholder_rows
)
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)
return super().combine_expression(connector, sub_expressions)
def combine_duration_expression(self, connector, sub_expressions):
if connector not in ['+', '-']:
raise utils.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
if internal_type == 'TimeField':
return "django_time_diff(%s, %s)" % (lhs_sql, rhs_sql), lhs_params + rhs_params
return "django_timestamp_diff(%s, %s)" % (lhs_sql, rhs_sql), lhs_params + rhs_params
def insert_statement(self, ignore_conflicts=False):
return 'INSERT OR IGNORE INTO' if ignore_conflicts else super().insert_statement(ignore_conflicts)
|
8bc17835ac2bf21b892bf49036bf250376f09cff6b98e9a046c733b0ebb5fe21 | import copy
from decimal import Decimal
from django.apps.registry import Apps
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.backends.ddl_references import Statement
from django.db.models import UniqueConstraint
from django.db.transaction import atomic
from django.db.utils import NotSupportedError
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_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 _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
constraints = self.connection.introspection._get_foreign_key_constraints(cursor, other_table.name)
for constraint in constraints.values():
constraint_table, constraint_column = constraint['foreign_key']
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):
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.quote_value(
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.quote_value(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' % 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. 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)
self._remake_table(model, create_field=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 the PK type changed.
if old_field.primary_key and new_field.primary_key and old_type != new_type:
for rel in new_field.model._meta.related_objects:
if not rel.many_to_many:
self._remake_table(rel.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:
super().add_constraint(model, constraint)
else:
self._remake_table(model)
def remove_constraint(self, model, constraint):
if isinstance(constraint, UniqueConstraint) and constraint.condition:
super().remove_constraint(model, constraint)
else:
self._remake_table(model)
|
89ea719dc1f92e7f8e3ed8a064e7276d388af652d5b2801220e0b6216bb3840b | import os
import shutil
import sys
from django.db.backends.base.creation import BaseDatabaseCreation
class DatabaseCreation(BaseDatabaseCreation):
@staticmethod
def is_in_memory_db(database_name):
return database_name == ':memory:' or 'mode=memory' in database_name
def _get_test_db_name(self):
test_database_name = self.connection.settings_dict['TEST']['NAME'] or ':memory:'
if test_database_name == ':memory:':
return 'file:memorydb_%s?mode=memory&cache=shared' % self.connection.alias
return test_database_name
def _create_test_db(self, verbosity, autoclobber, keepdb=False):
test_database_name = self._get_test_db_name()
if keepdb:
return test_database_name
if not self.is_in_memory_db(test_database_name):
# Erase the old test database
if verbosity >= 1:
self.log('Destroying old test database for alias %s...' % (
self._get_database_display_str(verbosity, test_database_name),
))
if os.access(test_database_name, os.F_OK):
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:
os.remove(test_database_name)
except Exception as e:
self.log('Got an error deleting the old test database: %s' % e)
sys.exit(2)
else:
self.log('Tests cancelled.')
sys.exit(1)
return test_database_name
def get_test_db_clone_settings(self, suffix):
orig_settings_dict = self.connection.settings_dict
source_database_name = orig_settings_dict['NAME']
if self.is_in_memory_db(source_database_name):
return orig_settings_dict
else:
root, ext = os.path.splitext(orig_settings_dict['NAME'])
return {**orig_settings_dict, 'NAME': '{}_{}.{}'.format(root, suffix, ext)}
def _clone_test_db(self, suffix, verbosity, keepdb=False):
source_database_name = self.connection.settings_dict['NAME']
target_database_name = self.get_test_db_clone_settings(suffix)['NAME']
# Forking automatically makes a copy of an in-memory database.
if not self.is_in_memory_db(source_database_name):
# Erase the old test database
if os.access(target_database_name, os.F_OK):
if keepdb:
return
if verbosity >= 1:
self.log('Destroying old test database for alias %s...' % (
self._get_database_display_str(verbosity, target_database_name),
))
try:
os.remove(target_database_name)
except Exception as e:
self.log('Got an error deleting the old test database: %s' % e)
sys.exit(2)
try:
shutil.copy(source_database_name, target_database_name)
except Exception as e:
self.log('Got an error cloning the test database: %s' % e)
sys.exit(2)
def _destroy_test_db(self, test_database_name, verbosity):
if test_database_name and not self.is_in_memory_db(test_database_name):
# Remove the SQLite database file
os.remove(test_database_name)
def test_db_signature(self):
"""
Return a tuple that uniquely identifies a test database.
This takes into account the special cases of ":memory:" and "" for
SQLite since the databases will be distinct despite having the same
TEST NAME. See https://www.sqlite.org/inmemorydb.html
"""
test_database_name = self._get_test_db_name()
sig = [self.connection.settings_dict['NAME']]
if self.is_in_memory_db(test_database_name):
sig.append(self.connection.alias)
return tuple(sig)
|
81ec42f49c41aa84662c8be22958b0adc2b316c7a18f35b461c2cbbd4e2cb63b | """
HTTP server that implements the Python WSGI protocol (PEP 333, rev 1.21).
Based on wsgiref.simple_server which is part of the standard library since 2.5.
This is a simple server for use in testing or debugging Django apps. It hasn't
been reviewed for security issues. DON'T USE IT FOR PRODUCTION USE!
"""
import logging
import socket
import socketserver
import sys
from wsgiref import simple_server
from django.core.exceptions import ImproperlyConfigured
from django.core.handlers.wsgi import LimitedStream
from django.core.wsgi import get_wsgi_application
from django.utils.module_loading import import_string
__all__ = ('WSGIServer', 'WSGIRequestHandler')
logger = logging.getLogger('django.server')
def get_internal_wsgi_application():
"""
Load and return the WSGI application as configured by the user in
``settings.WSGI_APPLICATION``. With the default ``startproject`` layout,
this will be the ``application`` object in ``projectname/wsgi.py``.
This function, and the ``WSGI_APPLICATION`` setting itself, are only useful
for Django's internal server (runserver); external WSGI servers should just
be configured to point to the correct application object directly.
If settings.WSGI_APPLICATION is not set (is ``None``), return
whatever ``django.core.wsgi.get_wsgi_application`` returns.
"""
from django.conf import settings
app_path = getattr(settings, 'WSGI_APPLICATION')
if app_path is None:
return get_wsgi_application()
try:
return import_string(app_path)
except ImportError as err:
raise ImproperlyConfigured(
"WSGI application '%s' could not be loaded; "
"Error importing module." % app_path
) from err
def is_broken_pipe_error():
exc_type, _, _ = sys.exc_info()
return issubclass(exc_type, BrokenPipeError)
class WSGIServer(simple_server.WSGIServer):
"""BaseHTTPServer that implements the Python WSGI protocol"""
request_queue_size = 10
def __init__(self, *args, ipv6=False, allow_reuse_address=True, **kwargs):
if ipv6:
self.address_family = socket.AF_INET6
self.allow_reuse_address = allow_reuse_address
super().__init__(*args, **kwargs)
def handle_error(self, request, client_address):
if is_broken_pipe_error():
logger.info("- Broken pipe from %s\n", client_address)
else:
super().handle_error(request, client_address)
class ThreadedWSGIServer(socketserver.ThreadingMixIn, WSGIServer):
"""A threaded version of the WSGIServer"""
daemon_threads = True
class ServerHandler(simple_server.ServerHandler):
http_version = '1.1'
def __init__(self, stdin, stdout, stderr, environ, **kwargs):
"""
Use a LimitedStream so that unread request data will be ignored at
the end of the request. WSGIRequest uses a LimitedStream but it
shouldn't discard the data since the upstream servers usually do this.
This fix applies only for testserver/runserver.
"""
try:
content_length = int(environ.get('CONTENT_LENGTH'))
except (ValueError, TypeError):
content_length = 0
super().__init__(LimitedStream(stdin, content_length), stdout, stderr, environ, **kwargs)
def cleanup_headers(self):
super().cleanup_headers()
# HTTP/1.1 requires support for persistent connections. Send 'close' if
# the content length is unknown to prevent clients from reusing the
# connection.
if 'Content-Length' not in self.headers:
self.headers['Connection'] = 'close'
# Mark the connection for closing if it's set as such above or if the
# application sent the header.
if self.headers.get('Connection') == 'close':
self.request_handler.close_connection = True
def close(self):
self.get_stdin()._read_limited()
super().close()
def handle_error(self):
# Ignore broken pipe errors, otherwise pass on
if not is_broken_pipe_error():
super().handle_error()
class WSGIRequestHandler(simple_server.WSGIRequestHandler):
protocol_version = 'HTTP/1.1'
def address_string(self):
# Short-circuit parent method to not call socket.getfqdn
return self.client_address[0]
def log_message(self, format, *args):
extra = {
'request': self.request,
'server_time': self.log_date_time_string(),
}
if args[1][0] == '4':
# 0x16 = Handshake, 0x03 = SSL 3.0 or TLS 1.x
if args[0].startswith('\x16\x03'):
extra['status_code'] = 500
logger.error(
"You're accessing the development server over HTTPS, but "
"it only supports HTTP.\n", extra=extra,
)
return
if args[1].isdigit() and len(args[1]) == 3:
status_code = int(args[1])
extra['status_code'] = status_code
if status_code >= 500:
level = logger.error
elif status_code >= 400:
level = logger.warning
else:
level = logger.info
else:
level = logger.info
level(format, *args, extra=extra)
def get_environ(self):
# Strip all headers with underscores in the name before constructing
# the WSGI environ. This prevents header-spoofing based on ambiguity
# between underscores and dashes both normalized to underscores in WSGI
# env vars. Nginx and Apache 2.4+ both do this as well.
for k in self.headers:
if '_' in k:
del self.headers[k]
return super().get_environ()
def handle(self):
self.close_connection = True
self.handle_one_request()
while not self.close_connection:
self.handle_one_request()
try:
self.connection.shutdown(socket.SHUT_WR)
except (AttributeError, OSError):
pass
def handle_one_request(self):
"""Copy of WSGIRequestHandler.handle() but with different ServerHandler"""
self.raw_requestline = self.rfile.readline(65537)
if len(self.raw_requestline) > 65536:
self.requestline = ''
self.request_version = ''
self.command = ''
self.send_error(414)
return
if not self.parse_request(): # An error code has been sent, just exit
return
handler = ServerHandler(
self.rfile, self.wfile, self.get_stderr(), self.get_environ()
)
handler.request_handler = self # backpointer for logging & connection closing
handler.run(self.server.get_app())
def run(addr, port, wsgi_handler, ipv6=False, threading=False, server_cls=WSGIServer):
server_address = (addr, port)
if threading:
httpd_cls = type('WSGIServer', (socketserver.ThreadingMixIn, server_cls), {})
else:
httpd_cls = server_cls
httpd = httpd_cls(server_address, WSGIRequestHandler, ipv6=ipv6)
if threading:
# ThreadingMixIn.daemon_threads indicates how threads will behave on an
# abrupt shutdown; like quitting the server by the user or restarting
# by the auto-reloader. True means the server will not wait for thread
# termination before it quits. This will make auto-reloader faster
# and will prevent the need to kill the server manually if a thread
# isn't terminating correctly.
httpd.daemon_threads = True
httpd.set_app(wsgi_handler)
httpd.serve_forever()
|
cb2d727b66ee294d8f07cf388ca9b3a7c8c11883db3e109ade77e55ee95569f4 | """
The temp module provides a NamedTemporaryFile that can be reopened in the same
process on any platform. Most platforms use the standard Python
tempfile.NamedTemporaryFile class, but Windows users are given a custom class.
This is needed because the Python implementation of NamedTemporaryFile uses the
O_TEMPORARY flag under Windows, which prevents the file from being reopened
if the same flag is not provided [1][2]. Note that this does not address the
more general issue of opening a file for writing and reading in multiple
processes in a manner that works across platforms.
The custom version of NamedTemporaryFile doesn't support the same keyword
arguments available in tempfile.NamedTemporaryFile.
1: https://mail.python.org/pipermail/python-list/2005-December/336957.html
2: https://bugs.python.org/issue14243
"""
import os
import tempfile
from django.core.files.utils import FileProxyMixin
__all__ = ('NamedTemporaryFile', 'gettempdir',)
if os.name == 'nt':
class TemporaryFile(FileProxyMixin):
"""
Temporary file object constructor that supports reopening of the
temporary file in Windows.
Unlike tempfile.NamedTemporaryFile from the standard library,
__init__() doesn't support the 'delete', 'buffering', 'encoding', or
'newline' keyword arguments.
"""
def __init__(self, mode='w+b', bufsize=-1, suffix='', prefix='', dir=None):
fd, name = tempfile.mkstemp(suffix=suffix, prefix=prefix, dir=dir)
self.name = name
self.file = os.fdopen(fd, mode, bufsize)
self.close_called = False
# Because close can be called during shutdown
# we need to cache os.unlink and access it
# as self.unlink only
unlink = os.unlink
def close(self):
if not self.close_called:
self.close_called = True
try:
self.file.close()
except OSError:
pass
try:
self.unlink(self.name)
except OSError:
pass
def __del__(self):
self.close()
def __enter__(self):
self.file.__enter__()
return self
def __exit__(self, exc, value, tb):
self.file.__exit__(exc, value, tb)
NamedTemporaryFile = TemporaryFile
else:
NamedTemporaryFile = tempfile.NamedTemporaryFile
gettempdir = tempfile.gettempdir
|
8ec62c1376cda4081a41c52f4c4f26d544e3e875579077786e1f98dfc26617ce | import os
from io import BytesIO, StringIO, UnsupportedOperation
from django.core.files.utils import FileProxyMixin
from django.utils.functional import cached_property
class File(FileProxyMixin):
DEFAULT_CHUNK_SIZE = 64 * 2 ** 10
def __init__(self, file, name=None):
self.file = file
if name is None:
name = getattr(file, 'name', None)
self.name = name
if hasattr(file, 'mode'):
self.mode = file.mode
def __str__(self):
return self.name or ''
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self or "None")
def __bool__(self):
return bool(self.name)
def __len__(self):
return self.size
@cached_property
def size(self):
if hasattr(self.file, 'size'):
return self.file.size
if hasattr(self.file, 'name'):
try:
return os.path.getsize(self.file.name)
except (OSError, TypeError):
pass
if hasattr(self.file, 'tell') and hasattr(self.file, 'seek'):
pos = self.file.tell()
self.file.seek(0, os.SEEK_END)
size = self.file.tell()
self.file.seek(pos)
return size
raise AttributeError("Unable to determine the file's size.")
def chunks(self, chunk_size=None):
"""
Read the file and yield chunks of ``chunk_size`` bytes (defaults to
``File.DEFAULT_CHUNK_SIZE``).
"""
chunk_size = chunk_size or self.DEFAULT_CHUNK_SIZE
try:
self.seek(0)
except (AttributeError, UnsupportedOperation):
pass
while True:
data = self.read(chunk_size)
if not data:
break
yield data
def multiple_chunks(self, chunk_size=None):
"""
Return ``True`` if you can expect multiple chunks.
NB: If a particular file representation is in memory, subclasses should
always return ``False`` -- there's no good reason to read from memory in
chunks.
"""
return self.size > (chunk_size or self.DEFAULT_CHUNK_SIZE)
def __iter__(self):
# Iterate over this file-like object by newlines
buffer_ = None
for chunk in self.chunks():
for line in chunk.splitlines(True):
if buffer_:
if endswith_cr(buffer_) and not equals_lf(line):
# Line split after a \r newline; yield buffer_.
yield buffer_
# Continue with line.
else:
# Line either split without a newline (line
# continues after buffer_) or with \r\n
# newline (line == b'\n').
line = buffer_ + line
# buffer_ handled, clear it.
buffer_ = None
# If this is the end of a \n or \r\n line, yield.
if endswith_lf(line):
yield line
else:
buffer_ = line
if buffer_ is not None:
yield buffer_
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, tb):
self.close()
def open(self, mode=None):
if not self.closed:
self.seek(0)
elif self.name and os.path.exists(self.name):
self.file = open(self.name, mode or self.mode)
else:
raise ValueError("The file cannot be reopened.")
return self
def close(self):
self.file.close()
class ContentFile(File):
"""
A File-like object that takes just raw content, rather than an actual file.
"""
def __init__(self, content, name=None):
stream_class = StringIO if isinstance(content, str) else BytesIO
super().__init__(stream_class(content), name=name)
self.size = len(content)
def __str__(self):
return 'Raw content'
def __bool__(self):
return True
def open(self, mode=None):
self.seek(0)
return self
def close(self):
pass
def write(self, data):
self.__dict__.pop('size', None) # Clear the computed size.
return self.file.write(data)
def endswith_cr(line):
"""Return True if line (a text or bytestring) ends with '\r'."""
return line.endswith('\r' if isinstance(line, str) else b'\r')
def endswith_lf(line):
"""Return True if line (a text or bytestring) ends with '\n'."""
return line.endswith('\n' if isinstance(line, str) else b'\n')
def equals_lf(line):
"""Return True if line (a text or bytestring) equals '\n'."""
return line == ('\n' if isinstance(line, str) else b'\n')
|
ff8c469ba842574e57e78558d009048d815a35c37ce71de169b943d89f63c92e | """
Move a file in the safest way possible::
>>> from django.core.files.move import file_move_safe
>>> file_move_safe("/tmp/old_file", "/tmp/new_file")
"""
import errno
import os
from shutil import copystat
from django.core.files import locks
__all__ = ['file_move_safe']
def _samefile(src, dst):
# Macintosh, Unix.
if hasattr(os.path, 'samefile'):
try:
return os.path.samefile(src, dst)
except OSError:
return False
# All other platforms: check for same pathname.
return (os.path.normcase(os.path.abspath(src)) ==
os.path.normcase(os.path.abspath(dst)))
def file_move_safe(old_file_name, new_file_name, chunk_size=1024 * 64, allow_overwrite=False):
"""
Move a file from one location to another in the safest way possible.
First, try ``os.rename``, which is simple but will break across filesystems.
If that fails, stream manually from one file to another in pure Python.
If the destination file exists and ``allow_overwrite`` is ``False``, raise
``FileExistsError``.
"""
# There's no reason to move if we don't have to.
if _samefile(old_file_name, new_file_name):
return
try:
if not allow_overwrite and os.access(new_file_name, os.F_OK):
raise FileExistsError('Destination file %s exists and allow_overwrite is False.' % new_file_name)
os.rename(old_file_name, new_file_name)
return
except OSError:
# OSError happens with os.rename() if moving to another filesystem or
# when moving opened files on certain operating systems.
pass
# first open the old file, so that it won't go away
with open(old_file_name, 'rb') as old_file:
# now open the new file, not forgetting allow_overwrite
fd = os.open(new_file_name, (os.O_WRONLY | os.O_CREAT | getattr(os, 'O_BINARY', 0) |
(os.O_EXCL if not allow_overwrite else 0)))
try:
locks.lock(fd, locks.LOCK_EX)
current_chunk = None
while current_chunk != b'':
current_chunk = old_file.read(chunk_size)
os.write(fd, current_chunk)
finally:
locks.unlock(fd)
os.close(fd)
try:
copystat(old_file_name, new_file_name)
except PermissionError as e:
# Certain filesystems (e.g. CIFS) fail to copy the file's metadata if
# the type of the destination filesystem isn't the same as the source
# filesystem; ignore that.
if e.errno != errno.EPERM:
raise
try:
os.remove(old_file_name)
except PermissionError as e:
# Certain operating systems (Cygwin and Windows)
# fail when deleting opened files, ignore it. (For the
# systems where this happens, temporary files will be auto-deleted
# on close anyway.)
if getattr(e, 'winerror', 0) != 32:
raise
|
8e6176f454354476754a2a3a84d8c9e85615022cf92504e4032a97eea5920050 | """
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:
file = open(file_or_path, 'rb')
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)
|
a403777e94d2ea85beb3e897a8e07681f9b6738b291eca321e33afe398fbd750 | import os
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.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)
return self._save(name, content)
# 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_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.
"""
dir_name, file_name = os.path.split(name)
file_root, file_ext = os.path.splitext(file_name)
# If the filename already exists, add an underscore and a random 7
# character alphanumeric string (before the file extension, if one
# exists) to the filename until the generated filename 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, "%s_%s%s" % (file_root, get_random_string(7), 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, "%s_%s%s" % (file_root, get_random_string(7), 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` may include a path as returned by FileField.upload_to.
dirname, filename = os.path.split(filename)
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:
# os.makedirs applies the global umask, so we reset it,
# for consistency with file_permissions_mode behavior.
old_umask = os.umask(0)
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)
# Store filenames with forward slashes, even on Windows.
return name.replace('\\', '/')
def delete(self, name):
assert name, "The name argument is not allowed to be empty."
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.exists(self.path(name))
def listdir(self, path):
path = self.path(path)
directories, files = [], []
for entry in os.scandir(path):
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.
"""
if settings.USE_TZ:
# Safe to use .replace() because UTC doesn't have DST
return datetime.utcfromtimestamp(ts).replace(tzinfo=timezone.utc)
else:
return datetime.fromtimestamp(ts)
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()
|
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