一对一关系的创建

from django.db import models

class Place(models.Model):
    name = models.CharField(max_length=50)
    address = models.CharField(max_length=80)

    def __str__(self):              # __unicode__ on Python 2
        return "%s the place" % self.name

class Restaurant(models.Model):
    place = models.OneToOneField(Place, primary_key=True)
    serves_hot_dogs = models.BooleanField(default=False)
    serves_pizza = models.BooleanField(default=False)

    def __str__(self):              # __unicode__ on Python 2
        return "%s the restaurant" % self.place.name

class Waiter(models.Model):
    restaurant = models.ForeignKey(Restaurant)
    name = models.CharField(max_length=50)

    def __str__(self):              # __unicode__ on Python 2
        return "%s the waiter at %s" % (self.name, self.restaurant)

一对一关系的使用

#创建几个Places对象：
>>> p1 = Place(name='Demon Dogs', address='944 W. Fullerton')
>>> p1.save()
>>> p2 = Place(name='Ace Hardware', address='1013 N. Ashland')
>>> p2.save()

# 创建Restaurant对象。
>>> r = Restaurant(place=p1, serves_hot_dogs=True, serves_pizza=False)
>>> r.save()

# 调用
>>> r.place
<Place: Demon Dogs the place>

# 从Place对象可以访问它的Restaurant(如果存在的话)：注意一对一关系和一对多和多对多他们的调用方法都不一样
>>> p1.restaurant
<Restaurant: Demon Dogs the restaurant>