--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/thirdparty/google_appengine/lib/django/tests/modeltests/custom_managers/models.py	Tue Aug 26 21:49:54 2008 +0000
@@ -0,0 +1,107 @@
+"""
+23. Giving models a custom manager
+
+You can use a custom ``Manager`` in a particular model by extending the base
+``Manager`` class and instantiating your custom ``Manager`` in your model.
+
+There are two reasons you might want to customize a ``Manager``: to add extra
+``Manager`` methods, and/or to modify the initial ``QuerySet`` the ``Manager``
+returns.
+"""
+
+from django.db import models
+
+# An example of a custom manager called "objects".
+
+class PersonManager(models.Manager):
+    def get_fun_people(self):
+        return self.filter(fun=True)
+
+class Person(models.Model):
+    first_name = models.CharField(maxlength=30)
+    last_name = models.CharField(maxlength=30)
+    fun = models.BooleanField()
+    objects = PersonManager()
+
+    def __str__(self):
+        return "%s %s" % (self.first_name, self.last_name)
+
+# An example of a custom manager that sets get_query_set().
+
+class PublishedBookManager(models.Manager):
+    def get_query_set(self):
+        return super(PublishedBookManager, self).get_query_set().filter(is_published=True)
+
+class Book(models.Model):
+    title = models.CharField(maxlength=50)
+    author = models.CharField(maxlength=30)
+    is_published = models.BooleanField()
+    published_objects = PublishedBookManager()
+    authors = models.ManyToManyField(Person, related_name='books')
+
+    def __str__(self):
+        return self.title
+
+# An example of providing multiple custom managers.
+
+class FastCarManager(models.Manager):
+    def get_query_set(self):
+        return super(FastCarManager, self).get_query_set().filter(top_speed__gt=150)
+
+class Car(models.Model):
+    name = models.CharField(maxlength=10)
+    mileage = models.IntegerField()
+    top_speed = models.IntegerField(help_text="In miles per hour.")
+    cars = models.Manager()
+    fast_cars = FastCarManager()
+
+    def __str__(self):
+        return self.name
+
+__test__ = {'API_TESTS':"""
+>>> p1 = Person(first_name='Bugs', last_name='Bunny', fun=True)
+>>> p1.save()
+>>> p2 = Person(first_name='Droopy', last_name='Dog', fun=False)
+>>> p2.save()
+>>> Person.objects.get_fun_people()
+[<Person: Bugs Bunny>]
+
+# The RelatedManager used on the 'books' descriptor extends the default manager
+>>> from modeltests.custom_managers.models import PublishedBookManager
+>>> isinstance(p2.books, PublishedBookManager)
+True
+
+>>> b1 = Book(title='How to program', author='Rodney Dangerfield', is_published=True)
+>>> b1.save()
+>>> b2 = Book(title='How to be smart', author='Albert Einstein', is_published=False)
+>>> b2.save()
+
+# The default manager, "objects", doesn't exist,
+# because a custom one was provided.
+>>> Book.objects
+Traceback (most recent call last):
+    ...
+AttributeError: type object 'Book' has no attribute 'objects'
+
+# The RelatedManager used on the 'authors' descriptor extends the default manager
+>>> from modeltests.custom_managers.models import PersonManager
+>>> isinstance(b2.authors, PersonManager)
+True
+
+>>> Book.published_objects.all()
+[<Book: How to program>]
+
+>>> c1 = Car(name='Corvette', mileage=21, top_speed=180)
+>>> c1.save()
+>>> c2 = Car(name='Neon', mileage=31, top_speed=100)
+>>> c2.save()
+>>> Car.cars.order_by('name')
+[<Car: Corvette>, <Car: Neon>]
+>>> Car.fast_cars.all()
+[<Car: Corvette>]
+
+# Each model class gets a "_default_manager" attribute, which is a reference
+# to the first manager defined in the class. In this case, it's "cars".
+>>> Car._default_manager.order_by('name')
+[<Car: Corvette>, <Car: Neon>]
+"""}