问题
I have got
Foo <=> FooGroup <=> Bar
relation, where <=> stands for ManyToMany field.
How do I retrieve all the Foos for a specific Bar instance?
回答1:
Here's an example with auth models, where the relationship is very much like your structure : User <=> Groups <=> Permission
from django.contrib.auth import models
models.Permission.objects.filter(group__user=models.User.objects.get(username="webmaster"))
With your example:
Foo.objects.filter(foogroup__bar=barinstance)
来源：https://stackoverflow.com/questions/1388137/querying-django-manytomany