#33160: postgresql DatabaseWrapper._nodb_cursor causes confusing/wrong "Django
was
unable to create a connection to the 'postgres' database" warning in case
of errors from queries
-------------------------------------+-------------------------------------
Reporter: Daniel | Owner: nobody
Hahler |
Type: Bug | Status: new
Component: Database | Version: 3.2
layer (models, ORM) |
Severity: Normal | Keywords:
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
{{_nodb_cursor}} might cause a confusing/wrong warning, e.g. via
{{teardown_database}}:
{{{
[35] …/Vcs/django/django/test/utils.py(313)teardown_databases()
connection.creation.destroy_test_db(old_name, verbosity, keepdb)
[36]
…/Vcs/django/django/db/backends/base/creation.py(282)destroy_test_db()
self._destroy_test_db(test_database_name, verbosity)
[37]
…/Vcs/django/django/db/backends/base/creation.py(298)_destroy_test_db()
cursor.execute("DROP DATABASE %s"
[38] /usr/lib/python3.9/contextlib.py(137)__exit__()
self.gen.throw(typ, value, traceback)
> [39]
…/Vcs/django/django/db/backends/postgresql/base.py(306)_nodb_cursor()
warnings.warn(
(Pdb++) l
301 with super()._nodb_cursor() as cursor:
302 yield cursor
303 except (Database.DatabaseError, WrappedDatabaseError) as
exc:
304 e = exc
305 __import__('pdb').set_trace()
306 -> warnings.warn(
307 "Normally Django will use a connection to the
'postgres' database "
308 "to avoid running initialization queries against
the production "
309 "database when it's not needed (for example, when
running tests). "
310 "Django was unable to create a connection to the
'postgres' database "
311 "and will use the first PostgreSQL database
instead.",
(Pdb++) e
OperationalError('database "test_foo" is being accessed by other
users\nDETAIL: There is 1 other session using the database.\n')
}}}
As you can see there is another issue this will (partly) swallow/hide
then, apart from the message being just wrong: it is not the connection
that failed, but a query in there:
{{{
[37] >
…/django/django/db/backends/base/creation.py(298)_destroy_test_db(), 4
frames hidden
289 def _destroy_test_db(self, test_database_name, verbosity):
290 """
291 Internal implementation - remove the test db tables.
292 """
293 # Remove the test database to clean up after
294 # ourselves. Connect to the previous database (not the
test database)
295 # to do so, because it's not allowed to delete a database
while being
296 # connected to it.
297 with self._nodb_cursor() as cursor:
298 -> cursor.execute("DROP DATABASE %s"
299 %
self.connection.ops.quote_name(test_database_name))
}}}
Only {{connect()} should get wrapped/handled in {{_nodb_cursor}} probably
(in terms of adding the warning), which could be achieved by handling
specific exceptions only, or re-raising it in case a {{cursor}} was used
(i.e. it could connect).
--
Ticket URL: <https://code.djangoproject.com/ticket/33160>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
--
You received this message because you are subscribed to the Google Groups
"Django updates" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/django-updates/050.0632193e6dda3a50d484d7f0567146b4%40djangoproject.com.
