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
13768	'exclude' does not work with lists containing a 'None' element.	Felipe 'chronos' Prenholato	nobody	"This ticket covers use of 'None' (NULL for DB) in list of one '__in' lookup. 

Postgres at least, when run a query with a 'WHERE' like ""object_id in (NULL,'other val')"" returns a query with no 
rows, and ORM too, what is a problem because developer can think that query is right, so as Alex Gaynor said in #django-dev 'we can rewrite it as (value IN (other, vals) OR value IS NULL)' or raise a error in database backend (since in ORM we can't thinking that mongodb would allow it as 'apollo13' said).

My vode is to raise a error in database backend.

Here is code in python shell that show the problem:

'''In Django 1.1.X'''
{{{
>>> LogEntry.objects.exclude(object_id=None).count()
274527
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT (""django_admin_log"".""object_id"" IS NULL)',
 'time': '0.101'}

>>> LogEntry.objects.exclude(object_id__in=(None,)).count()
0
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT (""django_admin_log"".""object_id"" IN (NULL) AND NOT (""django_admin_log"".""object_id"" IS NULL))',
 'time': '0.085'}

>>> LogEntry.objects.exclude(object_id=None,object_id='None').count()
274443
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT (""django_admin_log"".""object_id"" = E\'None\'  AND NOT (""django_admin_log"".""object_id"" IS NULL))',
 'time': '0.122'}

>>> LogEntry.objects.exclude(object_id__in=(None,'None')).count()
0
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT (""django_admin_log"".""object_id"" IN (NULL, E\'None\') AND NOT (""django_admin_log"".""object_id"" IS NULL))',
 'time': '0.126'}
}}}

'''Django 1.2'''
{{{
>>> LogEntry.objects.exclude(object_id=None).count()
274527
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT (""django_admin_log"".""object_id"" IS NULL)',
 'time': '0.104'}

>>> LogEntry.objects.exclude(object_id__in=(None,)).count()
0
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT ((""django_admin_log"".""object_id"" IN (NULL) AND NOT (""django_admin_log"".""object_id"" IS NULL)))',
 'time': '0.088'}

>>> LogEntry.objects.exclude(Q(object_id=None),Q(object_id='None')).count()
274527
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT (""django_admin_log"".""object_id"" IS NULL AND ""django_admin_log"".""object_id"" = E\'None\' )',
 'time': '0.114'}

>>> LogEntry.objects.exclude(object_id__in=(None,'None')).count()
0
>>> connection.queries[-1]
{'sql': 'SELECT COUNT(*) FROM ""django_admin_log"" WHERE NOT ((""django_admin_log"".""object_id"" IN (NULL, E\'None\') AND NOT (""django_admin_log"".""object_id"" IS NULL)))',
 'time': '0.120'}
}}}
"	Bug	closed	Database layer (models, ORM)	1.2	Normal	duplicate	None, NULL, in, postgres, postgresql	niels.busch@…	Accepted	0	0	0	0	0	0