class A(models.Model):
name= models.CharField('类A', max_length=32)
class B(models.Model):
a= models.ForeignKey(A, verbose_name='A类',related_name = "test")
name = models.CharField('类B', max_length=16)
class C(models.Model):
a= models.ForeignKey(A, verbose_name='A类')
name = models.CharField('类C', max_length=16)
aa = A.objects.get(id=A_id)
b = B.objects.filter(a=aa).all()