#24766: annotation with Q object filters results
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Reporter: karyon | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.8
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 0
Easy pickings: 0 | UI/UX: 0
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I tried to annotate a query of UserProfiles with a boolean indicating
whether each user is in a specific group or not. Besides the fact that i
didn't find any obvious or easy to find solution for that, i encountered
the following oddity:
Any of these:
{{{
UserProfile.objects.annotate(is_member=Case(When(groups__name="Group
name", then=Value(True)), default=Value(False),
output_field=BooleanField()))
}}}
{{{
UserProfile.objects.annotate(is_member=ExpressionWrapper(Q(groups__name="Group
name"), output_field=BooleanField()))
}}}
returns only users that are in some group. Users without groups are not in
the result. This was unexpected since i didn't request any filtering.
The issue might be that both queries use inner joins. here's the sql:
{{{
'SELECT <snip>, CASE WHEN "auth_group"."name" = Group name THEN True ELSE
False END AS "is_member" FROM "evaluation_userprofile" INNER JOIN
"evaluation_userprofile_groups" ON ( "evaluation_userprofile"."id" =
"evaluation_userprofile_groups"."userprofile_id" ) INNER JOIN "auth_group"
ON ( "evaluation_userprofile_groups"."group_id" = "auth_group"."id" )'
}}}
{{{
'SELECT <snip>, "auth_group"."name" = Group name AS "is_member" FROM
"evaluation_userprofile" INNER JOIN "evaluation_userprofile_groups" ON (
"evaluation_userprofile"."id" =
"evaluation_userprofile_groups"."userprofile_id" ) INNER JOIN "auth_group"
O
N ( "evaluation_userprofile_groups"."group_id" = "auth_group"."id" )'
}}}
--
Ticket URL: <https://code.djangoproject.com/ticket/24766>
Django <https://code.djangoproject.com/>
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