Custom Aggregate: Return string (even if aggregate field is other type)

[Helmut]

I'm writing a custom aggregate that should return a comma-separated string of numbers. In my specific case, the aggregate field is an IntegerField, and so Django tries to cast the aggregate result to int. So then I specified "is_ordinal = False" on the class, but it is still trying to cast to int.

It seems like the code just checks if is_ordinal is True. If it's anything other than true, it casts to the type of the aggregate field. Might this be a bug, or is there another way to get it to not cast to int?

Thanks.

[Tim Graham]

I'm not sure if there's a bug there, however, there is a new ​expressions API in Django 1.8, and the code you referenced (django.db.models.sql.aggregates) is deprecated, so even if there is a bug there, it won't be fixed.

[Josh Smeaton]

To provide a little more information - new aggregates allow you to set the output_field, so you get to decide the python type that comes back (CharField or TextField in your case).

[Helmut]

Fantastic! I will use the new API then. Thanks, guys!