Fixed #163 -- Added 'pk' database API option, which is a shorthand for (primary_key)__exact

git-svn-id: http://code.djangoproject.com/svn/django/trunk@316 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 13 insertions, 0 deletions

diff --git a/docs/db-api.txt b/docs/db-api.txt
index 401d9d3260..cb5ec4783f 100644
--- a/docs/db-api.txt
+++ b/docs/db-api.txt
@@ -97,6 +97,19 @@ Multiple lookups are allowed, of course, and are translated as "AND"s::
 
 ...retrieves all polls published in January 2005 that have a question starting with "Would."
 
+For convenience, there's a ``pk`` lookup type, which translates into
+``(primary_key)__exact``. In the polls example, these two statements are
+equivalent::
+
+    polls.get_object(id__exact=3)
+    polls.get_object(pk=3)
+
+``pk`` lookups also work across joins. In the polls example, these two
+statements are equivalent::
+
+    choices.get_list(poll__id__exact=3)
+    choices.get_list(poll__pk=3)
+
 Ordering
 ========