id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
17886	LOUTER join not promoted across filter expression	milosu	nobody	"In my database I have a little bit complicated relations. The attached test case fails without applied patch.

The core of the problem is actually something like:

{{{
ModelA <-- ModelB ---0--> Model C --> Model D
                  <--0--> Model C --> Model D

}}}

When I put ModelA into django.contrib.admin changelist and try to search - the search fields containing fields from all above outlined models, the resulting queryset contains one INNER JOIN for the link between the second relation of Model C and Model D which removes from the result set those models for which the many2many link is empty - which I guess should not happen.

I think that the LEFT OUTER JOIN should propagage in this case across relations. Maybe this patch solves also other ORM OR-queries related problems present or already patched earlier..

The attached patch solves this problem and I hope it passes the whole Django test suite - although due to the time limitations I tried it only with ""queries"" and ""aggregation_regress tests"". With this patch I was running my app in production for 2 years now, so I expect it *should* work.

This bug was present in the Django ORM since the qs refactor branch was merged a few years ago so I think it does not need to be marked as 1.4 release bloker. But anyway..
"	Bug	closed	Database layer (models, ORM)	1.4-beta-1	Normal	fixed			Ready for checkin	1	0	0	0	0	0