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
24951	Error deleting from table with Foreign Key being Primary Key at the same point	Serge Travin	nobody	"Problem occurs, when trying to issue delete on queryset for a table like this:
{{{
class Derivative(models.Model):
    spot = models.OneToOneField(Spot, primary_key=True)
    flag = models.BooleanField(default=True)

Derivative.objects.filter(spot__name__icontains='name').delete()
}}}

Result is:
AssertionError: Can only delete from one table at a time.

However, if we have simple table like this:
{{{
class SimpleDerivative(models.Model):
    spot = models.OneToOneField(Spot)
    flag = models.BooleanField(default=True)
}}}
than there is no problem. Note, there is no primary_key for spot here.

Problem does not exist for Django 1.6 (I didn't check for previous versions)
And persits in 1.7 and 1.8

There is changed code between versions in:
django/db/models/sql/subqueries.py - DeleteQuery.delete_qs

right before the last line self.tables contains two tables, which leads to assertion error.

I provided sample project to reproduce issue - https://github.com/grumbler/django_delete_issue
Simply run the tests with the appropriate Django version  installed."	Bug	closed	Database layer (models, ORM)	1.8	Release blocker	fixed		hv@…	Accepted	1	0	0	1	0	0