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
9023	OneToOneField delete() problem	TheShark	nobody	"Accessing the automatic reverse relationship on an instance (w.sprocket in the following example) causes some type of caching to happen which results in my Sprocket getting caught up in a cascade delete() of a Widget erroneously. The following example works without the print statement, and my Sprocket s exists at the end. If I 'print w.sprocket' before clearing the relationship, my Sprocket gets deleted along with my Widget when it shouldn't. 

{{{
class Widget(models.Model):
    name = models.CharField(max_length=10)

    def __unicode__(self):
        return u'%s(%s)'%(self.name,self.pk)

class Sprocket(models.Model):
    name = models.CharField(max_length=10)
    w = models.OneToOneField(Widget, null=True, blank=True)

    def __unicode__(self):
        return u'%s(%s)'%(self.name,self.pk)

And the following sequence of operations:

w=Widget(name=""Some Widget"")
w.save()
s=Sprocket(name=""Some Sprocket"")
s.w=w
s.save()

assert Widget.objects.all().count()==1
assert Sprocket.objects.all().count()==1

#print w.sprocket
s.w=None
s.save()
w.delete()

assert Widget.objects.all().count()==0
assert Sprocket.objects.all().count()==1
}}}
"		closed	Database layer (models, ORM)	dev		fixed	OneToOneField delete cascade	juriejanbotha@… David Larlet	Accepted	1	0	0	1	0	0