Django filter the model on ManyToMany count?

Question

Suppose I have something like this in my models.py:

class Hipster(models.Model):
  name = CharField(max_length=50)

class Party(models.Model):
  organiser =          


        

Answer 1

If this works this is how I would do it.

Best way can mean a lot of things: best performance, most maintainable, etc. Therefore I will not say this is the best way, but I like to stick to the ORM features as much as possible since it seems more maintainable.

from django.db.models import Count

user = Hipster.objects.get(pk=1) 
hip_parties = (Party.objects.annotate(num_participants=Count('participants'))
                            .filter(organiser=user, num_participants__gt=0))