--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/tests/modeltests/custom_managers/models.py	Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,59 @@
+"""
+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(max_length=30)
+    last_name = models.CharField(max_length=30)
+    fun = models.BooleanField()
+    objects = PersonManager()
+
+    def __unicode__(self):
+        return u"%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(max_length=50)
+    author = models.CharField(max_length=30)
+    is_published = models.BooleanField()
+    published_objects = PublishedBookManager()
+    authors = models.ManyToManyField(Person, related_name='books')
+
+    def __unicode__(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(max_length=10)
+    mileage = models.IntegerField()
+    top_speed = models.IntegerField(help_text="In miles per hour.")
+    cars = models.Manager()
+    fast_cars = FastCarManager()
+
+    def __unicode__(self):
+        return self.name