1 from django.db import models

     2 

     3 class Poll(models.Model):

     4     question = models.CharField(max_length=200)

     5 

     6     def __unicode__(self):

     7         return u"Q: %s " % self.question

     8 

     9 class Choice(models.Model):

    10     poll = models.ForeignKey(Poll)

    11     choice = models.CharField(max_length=200)

    12 

    13     def __unicode__(self):

    14         return u"Choice: %s in poll %s" % (self.choice, self.poll)

    15 

    16 # A set of models with an inner one pointing to two outer ones.

    17 class OuterA(models.Model):

    18     pass

    19 

    20 class OuterB(models.Model):

    21     data = models.CharField(max_length=10)

    22 

    23 class Inner(models.Model):

    24     first = models.ForeignKey(OuterA)

    25     second = models.ForeignKey(OuterB, null=True)