diff -r 5ff1fc726848 -r c6bca38c1cbf parts/django/tests/modeltests/one_to_one/models.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/tests/modeltests/one_to_one/models.py	Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,47 @@
+"""
+10. One-to-one relationships
+
+To define a one-to-one relationship, use ``OneToOneField()``.
+
+In this example, a ``Place`` optionally can be a ``Restaurant``.
+"""
+
+from django.db import models, transaction, IntegrityError
+
+class Place(models.Model):
+    name = models.CharField(max_length=50)
+    address = models.CharField(max_length=80)
+
+    def __unicode__(self):
+        return u"%s the place" % self.name
+
+class Restaurant(models.Model):
+    place = models.OneToOneField(Place, primary_key=True)
+    serves_hot_dogs = models.BooleanField()
+    serves_pizza = models.BooleanField()
+
+    def __unicode__(self):
+        return u"%s the restaurant" % self.place.name
+
+class Waiter(models.Model):
+    restaurant = models.ForeignKey(Restaurant)
+    name = models.CharField(max_length=50)
+
+    def __unicode__(self):
+        return u"%s the waiter at %s" % (self.name, self.restaurant)
+
+class ManualPrimaryKey(models.Model):
+    primary_key = models.CharField(max_length=10, primary_key=True)
+    name = models.CharField(max_length = 50)
+
+class RelatedModel(models.Model):
+    link = models.OneToOneField(ManualPrimaryKey)
+    name = models.CharField(max_length = 50)
+
+class MultiModel(models.Model):
+    link1 = models.OneToOneField(Place)
+    link2 = models.OneToOneField(ManualPrimaryKey)
+    name = models.CharField(max_length=50)
+
+    def __unicode__(self):
+        return u"Multimodel %s" % self.name