python/lib/django_1_4/tests/modeltests/m2o_recursive/models.py

   1 """
   2 11. Relating an object to itself, many-to-one
   3
   4 To define a many-to-one relationship between a model and itself, use
   5 ``ForeignKey('self')``.
   6
   7 In this example, a ``Category`` is related to itself. That is, each
   8 ``Category`` has a parent ``Category``.
   9
  10 Set ``related_name`` to designate what the reverse relationship is called.
  11 """
  12
  13 from django.db import models
  14
  15
  16 class Category(models.Model):
  17     name = models.CharField(max_length=20)
  18     parent = models.ForeignKey('self', blank=True, null=True, related_name='child_set')
  19
  20     def __unicode__(self):
  21         return self.name
  22
  23 class Person(models.Model):
  24     full_name = models.CharField(max_length=20)
  25     mother = models.ForeignKey('self', null=True, related_name='mothers_child_set')
  26     father = models.ForeignKey('self', null=True, related_name='fathers_child_set')
  27
  28     def __unicode__(self):
  29         return self.full_name