Fixed #1142 -- Added multiple database support.

This monster of a patch is the result of Alex Gaynor's 2009 Google Summer of Code project.
Congratulations to Alex for a job well done.

Big thanks also go to:
 * Justin Bronn for keeping GIS in line with the changes,
 * Karen Tracey and Jani Tiainen for their help testing Oracle support
 * Brett Hoerner, Jon Loyens, and Craig Kimmerer for their feedback.
 * Malcolm Treddinick for his guidance during the GSoC submission process.
 * Simon Willison for driving the original design process
 * Cal Henderson for complaining about ponies he wanted.

... and everyone else too numerous to mention that helped to bring this feature into fruition.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11952 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/ref/models/options.txt

@@ -4,8 +4,9 @@
 Model ``Meta`` options
 ======================
 
-This document explains all the possible :ref:`metadata options <meta-options>`  that you can give your model in its internal
-``class Meta``.
+This document explains all the possible :ref:`metadata options
+<meta-options>` that you can give your model in its internal ``class
+Meta``.
 
 Available ``Meta`` options
 ==========================
@@ -242,4 +243,3 @@ The plural name for the object::
     verbose_name_plural = "stories"
 
 If this isn't given, Django will use :attr:`~Options.verbose_name` + ``"s"``.
-

docs/ref/models/querysets.txt

@@ -874,6 +874,24 @@ logically::
     # existing set of fields).
     Entry.objects.defer("body").only("headline", "body")
 
+``using(alias)``
+~~~~~~~~~~~~~~~~~~
+
+.. versionadded:: 1.2
+
+This method is for controlling which database the ``QuerySet`` will be
+evaluated against if you are using more than one database.  The only argument
+this method takes is the alias of a database, as defined in
+:setting:`DATABASES`.
+
+For example::
+
+    # queries the database with the 'default' alias.
+    >>> Entry.objects.all()
+
+    # queries the database with the 'backup' alias
+    >>> Entry.objects.using('backup')
+
 
 QuerySet methods that do not return QuerySets
 ---------------------------------------------