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
19102	Deletion using subqueries doesn't work for aggregates, extra or select_related	Anssi Kääriäinen	Anssi Kääriäinen	"Aggregates, extra and select_related add columns to the subselect. However, the subselect must contain only one column.

Example case (modified from #18676's example):
{{{
class OrgUnit(models.Model):
    name = models.CharField(max_length=64, unique=True)
    
class Login(models.Model):
    description = models.CharField(max_length=32)
    orgunit = models.ForeignKey(OrgUnit)

Login.objects.extra(
    select={'foo':'description'}
).annotate(
    n=models.Count('description')
).filter(n=1).select_related('orgunit').delete()
}}}

The above fails with ""too many columns in subquery"" for various databases.

I have a work-in-progress patch for this at: https://github.com/akaariai/django/commit/34a39ba8981638db2eb3fdb3d8d45393130a9d99

This is a regression caused by #18676, so marking as release blocker."	Bug	closed	Database layer (models, ORM)	dev	Release blocker	fixed		django@…	Ready for checkin	1	0	0	0	0	0