django.db.models.Sum does not work on BooleanField

[wiz]

Models are Point -(fkey)-> Group and i'm trying to annotate Group queryset with a number of total points and a number of "active" points. Point.active is a BooleanField.

Code:

queryset = Group.objects.annotate(
    point_count = Count('point'),
    points_active = Sum('point__active'))

Error:

Exception Type: DatabaseError at /kiosks/wl/
Exception Value: function sum(boolean) does not exist
LINE 1: ..."id", "kiwl_group"."title", "kiwl_group"."descr", SUM("kiwl_...
                                                             ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

However, there is a ​Bug Report which is marked "fixed" and it looks like there is something i could to to actually get a Sum on BoolanField-s.

[Claude Paroz]

Test showing failure

[Claude Paroz]

The attached test passes on SQLite and MySQL, but fails with PostgreSQL.

[Anssi Kääriäinen]

The problem here is that PostgreSQL would need a type cast to int. So, the SQL should look like SUM("some_boolean_field"::int) for the SUM to work. However I am not sure if doing this in Django is a good idea, mainly because this would complicate the code somewhat, and something like #11305 would solve the issue for the user by allowing generation of SQL like in the Mozilla bug report.

I am leaving this ticket still open, although I would like to close this as wontfix for the reasons mentioned above. Could this be marked duplicate (or "related to") to #11305?

[anonymous]

Can you please explain how to do it through django without using the patch?

[Raphael Michel]

This can be easily done using ​https://docs.djangoproject.com/en/1.8/ref/models/conditional-expressions/ since 1.8.