Filtering Many-to-Many relationship by Relationship field in Django

Question

I'm trying to filter many-to-many relationship by some through Class field.

Quoting the Django documentation, i will explain my goal

class Person(models.Model):       name = models.CharField(max_length=128)        def __unicode__(self):           return self.name  class Group(models.Model):       name = models.CharField(max_length=128)       members = models.ManyToManyField(Person, through='Membership')        def __unicode__(self):           return self.name  class Membership(models.Model):       person = models.ForeignKey(Person)       group = models.ForeignKey(Group)       date_joined = models.DateField()       invite_reason = models.CharField(max_length=64) 

In this example my goal sould be filter many to many relationship and obtain only the Person who has joined some Group starting from certain date (date_joined field).

Is it possible?

Answer 1

You can query across relationships with the django ORM (or in this case the reverse relationship):

person = Person.objects.filter(     membership__group=example_group,     membership__date_joined__gte=example_date )