Get Count On Filtered Subqueries In Template

If I have a parent model and a child model, how can I then list all child objects of a parent object, and have a filtered count for each child object, when listing them? To give an

Solution 1:

You're right that you'll have to do this in the view. You can use annotation to get the number of filtered articles for each subcategory:

from django.db.models import Count

defmy_view(request, other, arguments):
    ...
    subcategories = category.sub_category_set.filter(tag__tagname='xyz') \ 
                            .annotate(num_articles=Count('article__id'))
    ...

Pass subcategories to your template context, and in your template you can do this:

{% for subcategory in subcategories %}
    {{ subcategory.name }} -- {{ subcategory.num_articles }}
{% endfor %}