django/db/backends/mysql/features.py
import operator
from django.db.backends.base.features import BaseDatabaseFeatures
from django.utils.functional import cached_property
class DatabaseFeatures(BaseDatabaseFeatures):
empty_fetchmany_value = ()
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
has_select_for_update_nowait = 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
atomic_transactions = False
can_clone_databases = True
supports_comments = True
supports_comments_inline = True
supports_temporal_subtraction = True
supports_slicing_ordering_in_compound = True
supports_index_on_text_field = False
supports_over_clause = True
supports_frame_range_fixed_distance = True
supports_update_conflicts = True
delete_can_self_reference_subquery = 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;
"""
create_test_table_with_composite_primary_key = """
CREATE TABLE test_table_composite_pk (
column_1 INTEGER NOT NULL,
column_2 INTEGER NOT NULL,
PRIMARY KEY(column_1, column_2)
)
"""
# 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
insert_test_table_with_defaults = "INSERT INTO {} () VALUES ()"
supports_order_by_nulls_modifier = False
order_by_nulls_first = True
supports_logical_xor = True
supports_stored_generated_columns = True
supports_virtual_generated_columns = True
@cached_property
def minimum_database_version(self):
if self.connection.mysql_is_mariadb:
return (10, 5)
else:
return (8, 0, 11)
@cached_property
def test_collations(self):
charset = "utf8"
if (
self.connection.mysql_is_mariadb
and self.connection.mysql_version >= (10, 6)
) or (
not self.connection.mysql_is_mariadb
and self.connection.mysql_version >= (8, 0, 30)
):
# utf8 is an alias for utf8mb3 in MariaDB 10.6+ and MySQL 8.0.30+.
charset = "utf8mb3"
return {
"ci": f"{charset}_general_ci",
"non_default": f"{charset}_esperanto_ci",
"swedish_ci": f"{charset}_swedish_ci",
"virtual": f"{charset}_esperanto_ci",
}
test_now_utc_template = "UTC_TIMESTAMP(6)"
@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",
},
"UPDATE ... ORDER BY syntax on MySQL/MariaDB does not support ordering by"
"related fields.": {
"update.tests.AdvancedTests."
"test_update_ordered_by_inline_m2m_annotation",
"update.tests.AdvancedTests.test_update_ordered_by_m2m_annotation",
"update.tests.AdvancedTests.test_update_ordered_by_m2m_annotation_desc",
},
}
if self.connection.mysql_is_mariadb and (
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 not self.supports_explain_analyze:
skips.update(
{
"MariaDB and MySQL >= 8.0.18 specific.": {
"queries.test_explain.ExplainTests.test_mysql_analyze",
},
}
)
if "ONLY_FULL_GROUP_BY" in self.connection.sql_mode:
skips.update(
{
"GROUP BY cannot contain nonaggregated column when "
"ONLY_FULL_GROUP_BY mode is enabled on MySQL, see #34262.": {
"aggregation.tests.AggregateTestCase."
"test_group_by_nested_expression_with_params",
},
}
)
if self.connection.mysql_version < (8, 0, 31):
skips.update(
{
"Nesting of UNIONs at the right-hand side is not supported on "
"MySQL < 8.0.31": {
"queries.test_qs_combinators.QuerySetSetOperationTests."
"test_union_nested"
},
}
)
if not self.connection.mysql_is_mariadb:
skips.update(
{
"MySQL doesn't allow renaming columns referenced by generated "
"columns": {
"migrations.test_operations.OperationTests."
"test_invalid_generated_field_changes_on_rename_stored",
"migrations.test_operations.OperationTests."
"test_invalid_generated_field_changes_on_rename_virtual",
},
}
)
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
@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
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_column_check_constraints(self):
if self.connection.mysql_is_mariadb:
return True
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:
return True
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 True
@cached_property
def has_select_for_update_of(self):
return not self.connection.mysql_is_mariadb
@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 can_introspect_json_field(self):
if self.connection.mysql_is_mariadb:
return self.can_introspect_check_constraints
return True
@cached_property
def supports_index_column_ordering(self):
if self._mysql_storage_engine != "InnoDB":
return False
if self.connection.mysql_is_mariadb:
return self.connection.mysql_version >= (10, 8)
return True
@cached_property
def supports_expression_indexes(self):
return (
not self.connection.mysql_is_mariadb
and self._mysql_storage_engine != "MyISAM"
and self.connection.mysql_version >= (8, 0, 13)
)
@cached_property
def supports_select_intersection(self):
is_mariadb = self.connection.mysql_is_mariadb
return is_mariadb or self.connection.mysql_version >= (8, 0, 31)
supports_select_difference = property(
operator.attrgetter("supports_select_intersection")
)
@cached_property
def can_rename_index(self):
if self.connection.mysql_is_mariadb:
return self.connection.mysql_version >= (10, 5, 2)
return True
@cached_property
def supports_expression_defaults(self):
if self.connection.mysql_is_mariadb:
return True
return self.connection.mysql_version >= (8, 0, 13)
@cached_property
def has_native_uuid_field(self):
is_mariadb = self.connection.mysql_is_mariadb
return is_mariadb and self.connection.mysql_version >= (10, 7)
@cached_property
def allows_group_by_selected_pks(self):
if self.connection.mysql_is_mariadb:
return "ONLY_FULL_GROUP_BY" not in self.connection.sql_mode
return True