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
13293	r12900 breaks extra() with additional select clauses (Only applies to MySQL SQLCompiler)	Matthias Kestenholz	nobody	"[12900] breaks the following query:

{{{
Page.objects.filter(...).extra(select={'_url_length': 'LENGTH(_cached_url)'}).order_by('-_url_length')[0]
}}}

LENGTH(_cached_url) is prepended to the list of fields which should be selected, which makes the row tuple one element longer than the fields tuple:

http://code.djangoproject.com/browser/django/trunk/django/db/backends/mysql/compiler.py#L6

Note that this bug only manifests itself under the following conditions:

 1. The first model field is an AutoField
 2. The second field is a (Null)?BooleanField
 3. The retrieved model has a PK of 1L (0L would also work, but auto incrementing primary key fields never have a value of 0L)

The resulting model instance has True instead of 1L as its PK.
"		closed	Database layer (models, ORM)	dev		fixed	MySQL		Accepted	1	0	0	0	0	0