annotation with Q object filters results

[karyon]

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" ON ( "evaluation_userprofile_groups"."group_id" = "auth_group"."id" )'