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
2922	[patch] defining outer joins	mir@…	nobody	"(this is going to be discussed on the devel list)

I was looking for an easy way to define extra outer joins. It turned out that it's easy to extend the QuerySet.extra method with a 'joins' argument used like this:

{{{
notes = Note.objects.select_related().extra(
        joins=['left outer join %s rel1 on rel1.id=%s.release_beginn_id' % (Release._meta.db_table, Note._meta.db_table),
                'left outer join %s rel2  on rel2.id=%s.release_behoben_id' % (Release._meta.db_table, Note._meta.db_table)],
        where=['((%(notes_table)s.release_beginn_id is null or rel1.sort_value <= %(sort_value)d) '
                'and (%(notes_table)s.release_behoben_id is null or rel2.sort_value > %(sort_value)d))'
                % {'sort_value': version, 'notes_table': Note._meta.db_table}],
        ).select_related()
}}}
"	enhancement	closed	Database layer (models, ORM)		normal	fixed		sam@… django@…	Someday/Maybe	1	1	1	1	0	0