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Hotel/env/lib/python3.5/site-packages/django/db/backends/mysql/features.py

109 lines
3.9 KiB
Python

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_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
uses_savepoints = True
can_release_savepoints = True
atomic_transactions = False
supports_column_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'}
@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):
return self.connection.mysql_version >= (8, 0, 2)
@cached_property
def has_select_for_update_skip_locked(self):
return self.connection.mysql_version >= (8, 0, 1)
has_select_for_update_nowait = has_select_for_update_skip_locked
@cached_property
def needs_explain_extended(self):
# EXTENDED is deprecated (and not required) in 5.7 and removed in 8.0.
return 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