How does Django's ORM manage to fetch Foreign objects when they are accessed

Question

Been trying to figure this out for a couple of hours now and have gotten nowhere.

class other(models.Model):
    user = models.ForeignKey(User)


others = other.         


        

Answer 1

Properties can be used to implement this behaviour. Basically, your class definition will generate a class similar to the following:

class other(models.Model):
    def _get_user(self):
        ## o.users being accessed
        return User.objects.get(other_id=self.id)

    def _set_user(self, v):
        ## ...

    user = property(_get_user, _set_user)

The query on User will not be performed until you access the .user of an 'other' instance.