mirror of
https://github.com/django/django.git
synced 2025-09-26 12:09:19 +00:00
Merged the queryset-refactor branch into trunk.
This is a big internal change, but mostly backwards compatible with existing code. Also adds a couple of new features. Fixed #245, #1050, #1656, #1801, #2076, #2091, #2150, #2253, #2306, #2400, #2430, #2482, #2496, #2676, #2737, #2874, #2902, #2939, #3037, #3141, #3288, #3440, #3592, #3739, #4088, #4260, #4289, #4306, #4358, #4464, #4510, #4858, #5012, #5020, #5261, #5295, #5321, #5324, #5325, #5555, #5707, #5796, #5817, #5987, #6018, #6074, #6088, #6154, #6177, #6180, #6203, #6658 git-svn-id: http://code.djangoproject.com/svn/django/trunk@7477 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Malcolm Tredinnick
parent
c91a30f00f
commit
9c52d56f6f
57 changed files with 5717 additions and 1739 deletions
|
|
@ -1,11 +1,53 @@
|
|||
"""
|
||||
XX. Model inheritance
|
||||
|
||||
Model inheritance isn't yet supported.
|
||||
Model inheritance exists in two varieties:
|
||||
- abstract base classes which are a way of specifying common
|
||||
information inherited by the subclasses. They don't exist as a separate
|
||||
model.
|
||||
- non-abstract base classes (the default), which are models in their own
|
||||
right with their own database tables and everything. Their subclasses
|
||||
have references back to them, created automatically.
|
||||
|
||||
Both styles are demonstrated here.
|
||||
"""
|
||||
|
||||
from django.db import models
|
||||
|
||||
#
|
||||
# Abstract base classes
|
||||
#
|
||||
|
||||
class CommonInfo(models.Model):
|
||||
name = models.CharField(max_length=50)
|
||||
age = models.PositiveIntegerField()
|
||||
|
||||
class Meta:
|
||||
abstract = True
|
||||
ordering = ['name']
|
||||
|
||||
def __unicode__(self):
|
||||
return u'%s %s' % (self.__class__.__name__, self.name)
|
||||
|
||||
class Worker(CommonInfo):
|
||||
job = models.CharField(max_length=50)
|
||||
|
||||
class Student(CommonInfo):
|
||||
school_class = models.CharField(max_length=10)
|
||||
|
||||
class Meta:
|
||||
pass
|
||||
|
||||
#
|
||||
# Multi-table inheritance
|
||||
#
|
||||
|
||||
class Chef(models.Model):
|
||||
name = models.CharField(max_length=50)
|
||||
|
||||
def __unicode__(self):
|
||||
return u"%s the chef" % self.name
|
||||
|
||||
class Place(models.Model):
|
||||
name = models.CharField(max_length=50)
|
||||
address = models.CharField(max_length=80)
|
||||
|
|
@ -13,9 +55,20 @@ class Place(models.Model):
|
|||
def __unicode__(self):
|
||||
return u"%s the place" % self.name
|
||||
|
||||
class Restaurant(Place):
|
||||
class Rating(models.Model):
|
||||
rating = models.IntegerField(null=True, blank=True)
|
||||
|
||||
class Meta:
|
||||
abstract = True
|
||||
ordering = ['-rating']
|
||||
|
||||
class Restaurant(Place, Rating):
|
||||
serves_hot_dogs = models.BooleanField()
|
||||
serves_pizza = models.BooleanField()
|
||||
chef = models.ForeignKey(Chef, null=True, blank=True)
|
||||
|
||||
class Meta(Rating.Meta):
|
||||
db_table = 'my_restaurant'
|
||||
|
||||
def __unicode__(self):
|
||||
return u"%s the restaurant" % self.name
|
||||
|
|
@ -26,14 +79,58 @@ class ItalianRestaurant(Restaurant):
|
|||
def __unicode__(self):
|
||||
return u"%s the italian restaurant" % self.name
|
||||
|
||||
__test__ = {'API_TESTS':"""
|
||||
# Make sure Restaurant has the right fields in the right order.
|
||||
>>> [f.name for f in Restaurant._meta.fields]
|
||||
['id', 'name', 'address', 'serves_hot_dogs', 'serves_pizza']
|
||||
class Supplier(Place):
|
||||
customers = models.ManyToManyField(Restaurant, related_name='provider')
|
||||
|
||||
# Make sure ItalianRestaurant has the right fields in the right order.
|
||||
>>> [f.name for f in ItalianRestaurant._meta.fields]
|
||||
['id', 'name', 'address', 'serves_hot_dogs', 'serves_pizza', 'serves_gnocchi']
|
||||
def __unicode__(self):
|
||||
return u"%s the supplier" % self.name
|
||||
|
||||
class ParkingLot(Place):
|
||||
# An explicit link to the parent (we can control the attribute name).
|
||||
parent = models.OneToOneField(Place, primary_key=True, parent_link=True)
|
||||
main_site = models.ForeignKey(Place, related_name='lot')
|
||||
|
||||
def __unicode__(self):
|
||||
return u"%s the parking lot" % self.name
|
||||
|
||||
__test__ = {'API_TESTS':"""
|
||||
# The Student and Worker models both have 'name' and 'age' fields on them and
|
||||
# inherit the __unicode__() method, just as with normal Python subclassing.
|
||||
# This is useful if you want to factor out common information for programming
|
||||
# purposes, but still completely independent separate models at the database
|
||||
# level.
|
||||
|
||||
>>> w = Worker(name='Fred', age=35, job='Quarry worker')
|
||||
>>> w.save()
|
||||
>>> w2 = Worker(name='Barney', age=34, job='Quarry worker')
|
||||
>>> w2.save()
|
||||
>>> s = Student(name='Pebbles', age=5, school_class='1B')
|
||||
>>> s.save()
|
||||
>>> unicode(w)
|
||||
u'Worker Fred'
|
||||
>>> unicode(s)
|
||||
u'Student Pebbles'
|
||||
|
||||
# The children inherit the Meta class of their parents (if they don't specify
|
||||
# their own).
|
||||
>>> Worker.objects.values('name')
|
||||
[{'name': u'Barney'}, {'name': u'Fred'}]
|
||||
|
||||
# Since Student does not subclass CommonInfo's Meta, it has the effect of
|
||||
# completely overriding it. So ordering by name doesn't take place for Students.
|
||||
>>> Student._meta.ordering
|
||||
[]
|
||||
|
||||
# However, the CommonInfo class cannot be used as a normal model (it doesn't
|
||||
# exist as a model).
|
||||
>>> CommonInfo.objects.all()
|
||||
Traceback (most recent call last):
|
||||
...
|
||||
AttributeError: type object 'CommonInfo' has no attribute 'objects'
|
||||
|
||||
# The Place/Restaurant/ItalianRestaurant models, on the other hand, all exist
|
||||
# as independent models. However, the subclasses also have transparent access
|
||||
# to the fields of their ancestors.
|
||||
|
||||
# Create a couple of Places.
|
||||
>>> p1 = Place(name='Master Shakes', address='666 W. Jersey')
|
||||
|
|
@ -41,13 +138,131 @@ __test__ = {'API_TESTS':"""
|
|||
>>> p2 = Place(name='Ace Hardware', address='1013 N. Ashland')
|
||||
>>> p2.save()
|
||||
|
||||
# Test constructor for Restaurant.
|
||||
>>> r = Restaurant(name='Demon Dogs', address='944 W. Fullerton', serves_hot_dogs=True, serves_pizza=False)
|
||||
Test constructor for Restaurant.
|
||||
>>> r = Restaurant(name='Demon Dogs', address='944 W. Fullerton',serves_hot_dogs=True, serves_pizza=False, rating=2)
|
||||
>>> r.save()
|
||||
|
||||
# Test the constructor for ItalianRestaurant.
|
||||
>>> ir = ItalianRestaurant(name='Ristorante Miron', address='1234 W. Elm', serves_hot_dogs=False, serves_pizza=False, serves_gnocchi=True)
|
||||
>>> c = Chef(name="Albert")
|
||||
>>> c.save()
|
||||
>>> ir = ItalianRestaurant(name='Ristorante Miron', address='1234 W. Ash', serves_hot_dogs=False, serves_pizza=False, serves_gnocchi=True, rating=4, chef=c)
|
||||
>>> ir.save()
|
||||
>>> ir.address = '1234 W. Elm'
|
||||
>>> ir.save()
|
||||
|
||||
# Make sure Restaurant and ItalianRestaurant have the right fields in the right
|
||||
# order.
|
||||
>>> [f.name for f in Restaurant._meta.fields]
|
||||
['id', 'name', 'address', 'place_ptr', 'rating', 'serves_hot_dogs', 'serves_pizza', 'chef']
|
||||
>>> [f.name for f in ItalianRestaurant._meta.fields]
|
||||
['id', 'name', 'address', 'place_ptr', 'rating', 'serves_hot_dogs', 'serves_pizza', 'chef', 'restaurant_ptr', 'serves_gnocchi']
|
||||
>>> Restaurant._meta.ordering
|
||||
['-rating']
|
||||
|
||||
# Even though p.supplier for a Place 'p' (a parent of a Supplier), a Restaurant
|
||||
# object cannot access that reverse relation, since it's not part of the
|
||||
# Place-Supplier Hierarchy.
|
||||
>>> Place.objects.filter(supplier__name='foo')
|
||||
[]
|
||||
>>> Restaurant.objects.filter(supplier__name='foo')
|
||||
Traceback (most recent call last):
|
||||
...
|
||||
FieldError: Cannot resolve keyword 'supplier' into field. Choices are: address, chef, id, italianrestaurant, lot, name, place_ptr, provider, rating, serves_hot_dogs, serves_pizza
|
||||
|
||||
# Parent fields can be used directly in filters on the child model.
|
||||
>>> Restaurant.objects.filter(name='Demon Dogs')
|
||||
[<Restaurant: Demon Dogs the restaurant>]
|
||||
>>> ItalianRestaurant.objects.filter(address='1234 W. Elm')
|
||||
[<ItalianRestaurant: Ristorante Miron the italian restaurant>]
|
||||
|
||||
# Filters against the parent model return objects of the parent's type.
|
||||
>>> Place.objects.filter(name='Demon Dogs')
|
||||
[<Place: Demon Dogs the place>]
|
||||
|
||||
# Since the parent and child are linked by an automatically created
|
||||
# OneToOneField, you can get from the parent to the child by using the child's
|
||||
# name.
|
||||
>>> place = Place.objects.get(name='Demon Dogs')
|
||||
>>> place.restaurant
|
||||
<Restaurant: Demon Dogs the restaurant>
|
||||
|
||||
>>> Place.objects.get(name='Ristorante Miron').restaurant.italianrestaurant
|
||||
<ItalianRestaurant: Ristorante Miron the italian restaurant>
|
||||
>>> Restaurant.objects.get(name='Ristorante Miron').italianrestaurant
|
||||
<ItalianRestaurant: Ristorante Miron the italian restaurant>
|
||||
|
||||
# This won't work because the Demon Dogs restaurant is not an Italian
|
||||
# restaurant.
|
||||
>>> place.restaurant.italianrestaurant
|
||||
Traceback (most recent call last):
|
||||
...
|
||||
DoesNotExist: ItalianRestaurant matching query does not exist.
|
||||
|
||||
# Related objects work just as they normally do.
|
||||
|
||||
>>> s1 = Supplier(name="Joe's Chickens", address='123 Sesame St')
|
||||
>>> s1.save()
|
||||
>>> s1.customers = [r, ir]
|
||||
>>> s2 = Supplier(name="Luigi's Pasta", address='456 Sesame St')
|
||||
>>> s2.save()
|
||||
>>> s2.customers = [ir]
|
||||
|
||||
# This won't work because the Place we select is not a Restaurant (it's a
|
||||
# Supplier).
|
||||
>>> p = Place.objects.get(name="Joe's Chickens")
|
||||
>>> p.restaurant
|
||||
Traceback (most recent call last):
|
||||
...
|
||||
DoesNotExist: Restaurant matching query does not exist.
|
||||
|
||||
# But we can descend from p to the Supplier child, as expected.
|
||||
>>> p.supplier
|
||||
<Supplier: Joe's Chickens the supplier>
|
||||
|
||||
>>> ir.provider.order_by('-name')
|
||||
[<Supplier: Luigi's Pasta the supplier>, <Supplier: Joe's Chickens the supplier>]
|
||||
|
||||
>>> Restaurant.objects.filter(provider__name__contains="Chickens")
|
||||
[<Restaurant: Ristorante Miron the restaurant>, <Restaurant: Demon Dogs the restaurant>]
|
||||
>>> ItalianRestaurant.objects.filter(provider__name__contains="Chickens")
|
||||
[<ItalianRestaurant: Ristorante Miron the italian restaurant>]
|
||||
|
||||
>>> park1 = ParkingLot(name='Main St', address='111 Main St', main_site=s1)
|
||||
>>> park1.save()
|
||||
>>> park2 = ParkingLot(name='Well Lit', address='124 Sesame St', main_site=ir)
|
||||
>>> park2.save()
|
||||
|
||||
>>> Restaurant.objects.get(lot__name='Well Lit')
|
||||
<Restaurant: Ristorante Miron the restaurant>
|
||||
|
||||
# The update() command can update fields in parent and child classes at once
|
||||
# (although it executed multiple SQL queries to do so).
|
||||
>>> Restaurant.objects.filter(serves_hot_dogs=True, name__contains='D').update(name='Demon Puppies', serves_hot_dogs=False)
|
||||
>>> r1 = Restaurant.objects.get(pk=r.pk)
|
||||
>>> r1.serves_hot_dogs == False
|
||||
True
|
||||
>>> r1.name
|
||||
u'Demon Puppies'
|
||||
|
||||
# The values() command also works on fields from parent models.
|
||||
>>> d = {'rating': 4, 'name': u'Ristorante Miron'}
|
||||
>>> list(ItalianRestaurant.objects.values('name', 'rating')) == [d]
|
||||
True
|
||||
|
||||
# select_related works with fields from the parent object as if they were a
|
||||
# normal part of the model.
|
||||
>>> from django import db
|
||||
>>> from django.conf import settings
|
||||
>>> settings.DEBUG = True
|
||||
>>> db.reset_queries()
|
||||
>>> ItalianRestaurant.objects.all()[0].chef
|
||||
<Chef: Albert the chef>
|
||||
>>> len(db.connection.queries)
|
||||
2
|
||||
>>> ItalianRestaurant.objects.select_related('chef')[0].chef
|
||||
<Chef: Albert the chef>
|
||||
>>> len(db.connection.queries)
|
||||
3
|
||||
>>> settings.DEBUG = False
|
||||
|
||||
"""}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue