Return a django user that is in two models' many-to-many fields

Question

I have the models:

class Project(models.Model):
    project_collaborators = models.ManyToManyField(User)

class Node(models.Model):
    collaborators = models.ManyToManyField(User)
    project = models.ForeignKey(Project)

I would like to get all users that are node collaborators and also a project collaborator, assuming I have the pk of the node. What query would I need for that?

Answer 1

from django.db.models import F
User.objects.filter(node__pk=node.pk, project=F('node__project'))

That should work. Haven't tested it. If not, you can try this one as well:

User.objects.filter(node__pk=node.pk, project__node__pk=node.pk)

Assuming they both work, you might want to try both in something like django-debug-toolbar 's debugsqlshell management command to see what kind of query each produces and which might be more efficient.