id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
29813	backends.base.test_operations.DatabaseOperationTests fails on MySQL in isolation	Jon Dufresne	nobody	"When running the Django test `backends.base.test_operations.DatabaseOperationTests` in isolation with a MySQL configuration, it fails with the following error:

{{{
======================================================================
FAIL: test_window_frame_raise_not_supported_error (backends.base.test_operations.DatabaseOperationTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "".../django/django/test/testcases.py"", line 1114, in skip_wrapper
    if condition():
  File "".../django/django/test/testcases.py"", line 1135, in <lambda>
    lambda: any(getattr(connection.features, feature, False) for feature in features),
  File "".../django/django/test/testcases.py"", line 1135, in <genexpr>
    lambda: any(getattr(connection.features, feature, False) for feature in features),
  File "".../django/django/utils/functional.py"", line 37, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "".../django/django/db/backends/mysql/features.py"", line 84, in supports_over_clause
    if self.connection.mysql_is_mariadb:
  File "".../django/django/utils/functional.py"", line 37, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "".../django/django/db/backends/mysql/base.py"", line 344, in mysql_is_mariadb
    return 'mariadb' in self.mysql_server_info.lower()
  File "".../django/django/utils/functional.py"", line 37, in __get__
    res = instance.__dict__[self.name] = self.func(instance)
  File "".../django/django/db/backends/mysql/base.py"", line 330, in mysql_server_info
    with self.temporary_connection() as cursor:
  File ""/usr/lib64/python3.7/contextlib.py"", line 112, in __enter__
    return next(self.gen)
  File "".../django/django/db/backends/base/base.py"", line 577, in temporary_connection
    with self.cursor() as cursor:
  File "".../django/django/test/testcases.py"", line 144, in __call__
    ""set %s.allow_database_queries to True to silence this failure."" % self.cls_name
AssertionError: Database queries aren't allowed in SimpleTestCase. Either use TestCase or TransactionTestCase to ensure proper test isolation or set DatabaseOperationTests.allow_database_queries to True to silence this failure.
}}}

The test is using `SimpleTestCase`, but this test executes a query on MySQL for feature detection."	Bug	closed	Database layer (models, ORM)	dev	Normal	fixed			Unreviewed	1	0	0	0	0	0