#12807: Empty results break when part of ORs
-------------------------------------+-------------------------------------
Reporter: sciyoshi | Owner: nobody
Type: Bug | Status: new
Component: Database layer | Version: 1.1
(models, ORM) | Resolution:
Severity: Normal | Triage Stage: Accepted
Keywords: query, sql, q, | Needs documentation: 0
filter, or, empty | Patch needs improvement: 1
Has patch: 1 | UI/UX: 0
Needs tests: 0 |
Easy pickings: 0 |
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Description changed by akaariai:
Old description:
> The following query:
>
> User.objects.filter((Q(pk=3) | ~Q(pk__in=[]) & Q(pk=1))
>
> currently breaks, since ~Q(pk__in=[]) isn't noticed as being full, thus
> leading to the following query:
>
> >>> User.objects.filter((Q(pk=3) | ~Q(pk__in=[])) &
> Q(pk=1)).values('id').query.as_sql()
> ('SELECT "auth_user"."id" FROM "auth_user" WHERE (("auth_user"."id" =
> %s ) AND "auth_user"."id" = %s )', (3, 1))
>
> and giving an empty result set, instead of the correct
>
> >>> User.objects.filter((Q(pk=3) | ~Q(pk__in=[])) &
> Q(pk=1)).values('id').query.as_sql()
> ('SELECT "auth_user"."id" FROM "auth_user" WHERE ("auth_user"."id" =
> %s )', (1,))
>
> which returns the single user with PK 1.
>
> Attaching a patch which fixes it by making as_sql() raise FullResultSet
> and adds a test case. The issue could also be fixed by checking if the
> child's as_sql() is empty, but this seemed cleaner.
New description:
The following query:
`User.objects.filter((Q(pk=3) | ~Q(pk__in=[]) & Q(pk=1))`
currently breaks, since `~Q(pk__in=[])` isn't noticed as being full, thus
leading to the following query:
>>> `User.objects.filter((Q(pk=3) | ~Q(pk__in=[])) &
Q(pk=1)).values('id').query.as_sql()`
('SELECT "auth_user"."id" FROM "auth_user" WHERE (("auth_user"."id" =
%s ) AND "auth_user"."id" = %s )', (3, 1))
and giving an empty result set, instead of the correct
>>> `User.objects.filter((Q(pk=3) | ~Q(pk__in=[])) &
Q(pk=1)).values('id').query.as_sql()`
('SELECT "auth_user"."id" FROM "auth_user" WHERE ("auth_user"."id" =
%s )', (1,))
which returns the single user with PK 1.
Attaching a patch which fixes it by making as_sql() raise FullResultSet
and adds a test case. The issue could also be fixed by checking if the
child's as_sql() is empty, but this seemed cleaner.
--
--
Ticket URL: <https://code.djangoproject.com/ticket/12807#comment:7>
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