Django - How can you include annotated results in a serialized QuerySet?

Question

How can you include annotated results in a serialized QuerySet?

data = serializer.serialize(Books.objects.filter(publisher__id=id).annotate(num_books=Count(         


        

Answer 1

Based on the link, this has been solved by pull request (https://github.com/django/django/pull/1176) some months ago.

You need to add num_books as a property:

class Publisher():
    ....

    @property
    def num_books(self):
        return some_way_to_count('related_books')

and then call it like so:

data = serializer.serialize(Books.objects.filter(publisher__id=id)), use_natural_keys=True, extra=['num_books'])

I'm not too sure about the exact syntax, since I don't work much with serializers.