import operator from django.db.backends.base.features import BaseDatabaseFeatures from django.utils.functional import cached_property class DatabaseFeatures(BaseDatabaseFeatures): empty_fetchmany_value = () allows_group_by_pk = True related_fields_match_type = True # MySQL doesn't support sliced subqueries with IN/ALL/ANY/SOME. allow_sliced_subqueries_with_in = False has_select_for_update = True supports_forward_references = False supports_regex_backreferencing = False supports_date_lookup_using_string = False supports_timezones = False requires_explicit_null_ordering_when_grouping = True can_release_savepoints = True atomic_transactions = False can_clone_databases = True supports_temporal_subtraction = True supports_select_intersection = False supports_select_difference = False supports_slicing_ordering_in_compound = True supports_index_on_text_field = False 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; """ # Neither MySQL nor MariaDB support partial indexes. supports_partial_indexes = False # COLLATE must be wrapped in parentheses because MySQL treats COLLATE as an # indexed expression. collate_as_index_expression = True supports_order_by_nulls_modifier = False order_by_nulls_first = True @cached_property def test_collations(self): charset = 'utf8' if self.connection.mysql_is_mariadb and self.connection.mysql_version >= (10, 6): # utf8 is an alias for utf8mb3 in MariaDB 10.6+. charset = 'utf8mb3' return { 'ci': f'{charset}_general_ci', 'non_default': f'{charset}_esperanto_ci', 'swedish_ci': f'{charset}_swedish_ci', } test_now_utc_template = 'UTC_TIMESTAMP' @cached_property def django_test_skips(self): skips = { "This doesn't work on MySQL.": { 'db_functions.comparison.test_greatest.GreatestTests.test_coalesce_workaround', 'db_functions.comparison.test_least.LeastTests.test_coalesce_workaround', }, 'Running on MySQL requires utf8mb4 encoding (#18392).': { 'model_fields.test_textfield.TextFieldTests.test_emoji', 'model_fields.test_charfield.TestCharField.test_emoji', }, "MySQL doesn't support functional indexes on a function that " "returns JSON": { 'schema.tests.SchemaTests.test_func_index_json_key_transform', }, "MySQL supports multiplying and dividing DurationFields by a " "scalar value but it's not implemented (#25287).": { 'expressions.tests.FTimeDeltaTests.test_durationfield_multiply_divide', }, } if 'ONLY_FULL_GROUP_BY' in self.connection.sql_mode: skips.update({ 'GROUP BY optimization does not work properly when ' 'ONLY_FULL_GROUP_BY mode is enabled on MySQL, see #31331.': { 'aggregation.tests.AggregateTestCase.test_aggregation_subquery_annotation_multivalued', 'annotations.tests.NonAggregateAnnotationTestCase.test_annotation_aggregate_with_m2o', }, }) if not self.connection.mysql_is_mariadb and self.connection.mysql_version < (8,): skips.update({ 'Casting to datetime/time is not supported by MySQL < 8.0. (#30224)': { 'aggregation.tests.AggregateTestCase.test_aggregation_default_using_time_from_python', 'aggregation.tests.AggregateTestCase.test_aggregation_default_using_datetime_from_python', }, 'MySQL < 8.0 returns string type instead of datetime/time. (#30224)': { 'aggregation.tests.AggregateTestCase.test_aggregation_default_using_time_from_database', 'aggregation.tests.AggregateTestCase.test_aggregation_default_using_datetime_from_database', }, }) if ( self.connection.mysql_is_mariadb and (10, 4, 3) < self.connection.mysql_version < (10, 5, 2) ): skips.update({ 'https://jira.mariadb.org/browse/MDEV-19598': { 'schema.tests.SchemaTests.test_alter_not_unique_field_to_primary_key', }, }) if ( self.connection.mysql_is_mariadb and (10, 4, 12) < self.connection.mysql_version < (10, 5) ): skips.update({ 'https://jira.mariadb.org/browse/MDEV-22775': { 'schema.tests.SchemaTests.test_alter_pk_with_self_referential_field', }, }) if not self.supports_explain_analyze: skips.update({ 'MariaDB and MySQL >= 8.0.18 specific.': { 'queries.test_explain.ExplainTests.test_mysql_analyze', }, }) return skips @cached_property def _mysql_storage_engine(self): "Internal method used in Django tests. Don't rely on this from your code" return self.connection.mysql_server_data['default_storage_engine'] @cached_property def allows_auto_pk_0(self): """ Autoincrement primary key can be set to 0 if it doesn't generate new autoincrement values. """ return 'NO_AUTO_VALUE_ON_ZERO' in self.connection.sql_mode @cached_property def update_can_self_select(self): return self.connection.mysql_is_mariadb and self.connection.mysql_version >= (10, 3, 2) @cached_property def can_introspect_foreign_keys(self): "Confirm support for introspected foreign keys" return self._mysql_storage_engine != 'MyISAM' @cached_property def introspected_field_types(self): return { **super().introspected_field_types, 'BinaryField': 'TextField', 'BooleanField': 'IntegerField', 'DurationField': 'BigIntegerField', 'GenericIPAddressField': 'CharField', } @cached_property def can_return_columns_from_insert(self): return self.connection.mysql_is_mariadb and self.connection.mysql_version >= (10, 5, 0) can_return_rows_from_bulk_insert = property(operator.attrgetter('can_return_columns_from_insert')) @cached_property def has_zoneinfo_database(self): return self.connection.mysql_server_data['has_zoneinfo_database'] @cached_property def is_sql_auto_is_null_enabled(self): return self.connection.mysql_server_data['sql_auto_is_null'] @cached_property def supports_over_clause(self): if self.connection.mysql_is_mariadb: return True return self.connection.mysql_version >= (8, 0, 2) supports_frame_range_fixed_distance = property(operator.attrgetter('supports_over_clause')) @cached_property def supports_column_check_constraints(self): if self.connection.mysql_is_mariadb: return self.connection.mysql_version >= (10, 2, 1) return self.connection.mysql_version >= (8, 0, 16) supports_table_check_constraints = property(operator.attrgetter('supports_column_check_constraints')) @cached_property def can_introspect_check_constraints(self): if self.connection.mysql_is_mariadb: version = self.connection.mysql_version return (version >= (10, 2, 22) and version < (10, 3)) or version >= (10, 3, 10) return self.connection.mysql_version >= (8, 0, 16) @cached_property def has_select_for_update_skip_locked(self): if self.connection.mysql_is_mariadb: return self.connection.mysql_version >= (10, 6) return self.connection.mysql_version >= (8, 0, 1) @cached_property def has_select_for_update_nowait(self): if self.connection.mysql_is_mariadb: return self.connection.mysql_version >= (10, 3, 0) return self.connection.mysql_version >= (8, 0, 1) @cached_property def has_select_for_update_of(self): return not self.connection.mysql_is_mariadb and self.connection.mysql_version >= (8, 0, 1) @cached_property def supports_explain_analyze(self): return self.connection.mysql_is_mariadb or self.connection.mysql_version >= (8, 0, 18) @cached_property def supported_explain_formats(self): # Alias MySQL's TRADITIONAL to TEXT for consistency with other # backends. formats = {'JSON', 'TEXT', 'TRADITIONAL'} if not self.connection.mysql_is_mariadb and self.connection.mysql_version >= (8, 0, 16): formats.add('TREE') return formats @cached_property def supports_transactions(self): """ All storage engines except MyISAM support transactions. """ return self._mysql_storage_engine != 'MyISAM' @cached_property def ignores_table_name_case(self): return self.connection.mysql_server_data['lower_case_table_names'] @cached_property def supports_default_in_lead_lag(self): # To be added in https://jira.mariadb.org/browse/MDEV-12981. return not self.connection.mysql_is_mariadb @cached_property def supports_json_field(self): if self.connection.mysql_is_mariadb: return self.connection.mysql_version >= (10, 2, 7) return self.connection.mysql_version >= (5, 7, 8) @cached_property def can_introspect_json_field(self): if self.connection.mysql_is_mariadb: return self.supports_json_field and self.can_introspect_check_constraints return self.supports_json_field @cached_property def supports_index_column_ordering(self): return ( not self.connection.mysql_is_mariadb and self.connection.mysql_version >= (8, 0, 1) ) @cached_property def supports_expression_indexes(self): return ( not self.connection.mysql_is_mariadb and self.connection.mysql_version >= (8, 0, 13) )