text: from django.db.backends.base.features import BaseDatabaseFeatures
  from django.utils.functional import cached_property
  
  from .base import Database
  
  try:
      import pytz
  except ImportError:
      pytz = None
  
  
  class DatabaseFeatures(BaseDatabaseFeatures):
      empty_fetchmany_value = ()
      update_can_self_select = False
      allows_group_by_pk = True
      related_fields_match_type = True
      allow_sliced_subqueries = False
      has_bulk_insert = True
      has_select_for_update = True
      has_select_for_update_nowait = False
      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_small_integer_field = True
      supports_index_column_ordering = False
      supports_timezones = False
      requires_explicit_null_ordering_when_grouping = True
      allows_auto_pk_0 = False
      uses_savepoints = True
      can_release_savepoints = True
      atomic_transactions = False
      supports_column_check_constraints = False
      can_clone_databases = True
      supports_temporal_subtraction = True
  
      @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 supports_microsecond_precision(self):
          # See https://github.com/farcepest/MySQLdb1/issues/24 for the reason
          # about requiring MySQLdb 1.2.5
          return self.connection.mysql_version >= (5, 6, 4) and Database.version_info >= (1, 2, 5)
  
      @cached_property
      def has_zoneinfo_database(self):
          # MySQL accepts full time zones names (eg. Africa/Nairobi) but rejects
          # abbreviations (eg. EAT). When pytz isn't installed and the current
          # time zone is LocalTimezone (the only sensible value in this
          # context), the current time zone name will be an abbreviation. As a
          # consequence, MySQL cannot perform time zone conversions reliably.
          if pytz is None:
              return False
  
          # 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
  
      def introspected_boolean_field_type(self, *args, **kwargs):
          return 'IntegerField'
  
      @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
  