django1/django/db/backends/mysql/features.py

72 lines
2.6 KiB
Python

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_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
@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'