Django filter to include all tags for which a certain type of item exists

Question

I'm using django-taggit. I am tagging action items and info items. I want to list all tags for which there is an info item. I originally wrote:

Tag.objects.filter(info_item__name__isnull=False).annotate(info_item_count=Count('info_item'))

But this is returning some action items. How might I rewrite the query so that the Tags are filtered such that there is an info item attached?

Answer 1

Assuming your info_item model is InfoItem, then try

from django.contrib.contenttypes.models import ContentType  
Tag.objects.filter(
    taggit_taggeditem_items__content_type=ContentType.objects.get_for_model(InfoItem), 
    info_item__name__isnull=False).annotate(info_item_count=Count('info_item'))