Question

Let’s say I’m building an Article / Comment system like this:

class Article(models.Model):
    title = models.TextField()
    content = models.TextField()

class Comment(models.Model):
    article = ForeignKey(Article)
    content = models.TextField()

How can I filter Article.objects to find the articles that have more than ten comments?

Answer 1

You need to annotate your queryset with the number of comments for each article, then filter on the annotated field.

from django.db.models import Count
Article.objects.annotate(num_comments=Count('comment')).filter(num_comments__gt=10)