From f505bd6e415fc771c920b19432dd10941a743097 Mon Sep 17 00:00:00 2001
From: Malcolm Tredinnick <malcolm.tredinnick@gmail.com>
Date: Sat, 16 Aug 2008 22:44:42 +0000
Subject: [PATCH] Documented that GenericForeignKey fields can't be used
transparently in filters. Refs #3006. Patch from rmyers.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@8417 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
docs/contenttypes.txt | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/docs/contenttypes.txt b/docs/contenttypes.txt
index a07ff5d70d..84e38020bc 100644
--- a/docs/contenttypes.txt
+++ b/docs/contenttypes.txt
@@ -227,6 +227,16 @@ creating a ``TaggedItem``::
>>> t.content_object
<User: Guido>
+Due to the way ``GenericForeignKey`` is implemeneted, you cannot use such
+fields directly with filters (``filter()`` and ``exclude()``, for example) via
+the database API. They aren't normal field objects. These examples will *not*
+work::
+
+ # This will fail
+ >>> TaggedItem.objects.filter(content_object=guido)
+ # This will also fail
+ >>> TaggedItem.objects.get(content_object=guido)
+
Reverse generic relations
-------------------------