django1/tests/testapp/models/one_to_one.py

78 lines
2.1 KiB
Python

"""
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.core import meta
class Place(meta.Model):
name = meta.CharField(maxlength=50)
address = meta.CharField(maxlength=80)
def __repr__(self):
return "%s the place" % self.name
class Restaurant(meta.Model):
place = meta.OneToOneField(Place)
serves_hot_dogs = meta.BooleanField()
serves_pizza = meta.BooleanField()
def __repr__(self):
return "%s the restaurant" % self.get_place().name
class Waiter(meta.Model):
restaurant = meta.ForeignKey(Restaurant)
name = meta.CharField(maxlength=50)
def __repr__(self):
return "%s the waiter at %s" % (self.name, self.get_restaurant())
API_TESTS = """
# Create a couple of Places.
>>> p1 = places.Place(name='Demon Dogs', address='944 W. Fullerton')
>>> p1.save()
>>> p2 = places.Place(name='Ace Hardware', address='1013 N. Ashland')
>>> p2.save()
# Create a Restaurant. Pass the ID of the "parent" object as this object's ID.
>>> r = restaurants.Restaurant(place=p1, serves_hot_dogs=True, serves_pizza=False)
>>> r.save()
# A Restaurant can access its place.
>>> r.get_place()
Demon Dogs the place
# A Place can access its restaurant, if available.
>>> p1.get_restaurant()
Demon Dogs the restaurant
# p2 doesn't have an associated restaurant.
>>> p2.get_restaurant()
Traceback (most recent call last):
...
RestaurantDoesNotExist: Restaurant does not exist for {'place__id__exact': ...}
# restaurants.get_list() just returns the Restaurants, not the Places.
>>> restaurants.get_list()
[Demon Dogs the restaurant]
# places.get_list() returns all Places, regardless of whether they have
# Restaurants.
>>> places.get_list(order_by=['name'])
[Ace Hardware the place, Demon Dogs the place]
>>> restaurants.get_object(place__id__exact=1)
Demon Dogs the restaurant
>>> restaurants.get_object(pk=1)
Demon Dogs the restaurant
# Add a Waiter to the Restaurant.
>>> w = r.add_waiter(name='Joe')
>>> w.save()
>>> w
Joe the waiter at Demon Dogs the restaurant
"""