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
9039	Form validation problem for model with ForeignKey having unique=True,blank=True,null=True	nategriswold	Karen Tracey	"I'm having problems validating a form for the below models. Multiple null values in the below ""Thing"" model's ""other"" column seem to prevent the basic ModelForm from validating. This also happens for OneToOneFields of the same nature. Normal django db api functions and the database do not seem to have any problem. Basically, django forms are treating null as conflicting with null but the backend and db api are not. I don't think this is intended.

I also tried this in an older revision of django (r7477, using form_for_model) and did not have the problem there.

Thanks


{{{
class OtherThing(models.Model):
   pass

class Thing(models.Model):
   other = models.ForeignKey('OtherThing', null=True, blank=True, unique=True)

>>> import django
>>> django.get_version()
>>> from django.forms import ModelForm
>>> from test.models import *
>>>
>>> class ThingForm(ModelForm):
...   class Meta:
...     model = Thing
...
>>> Thing.objects.all()
[]
>>> ThingForm({}).save()
<Thing: Thing object>
>>> ThingForm({}).save()
Traceback (most recent call last):
 File ""<console>"", line 1, in ?
 File ""/home/griswold/lib/python/django/forms/models.py"", line 302, in save
   return save_instance(self, self.instance, self._meta.fields,
fail_message, commit)
 File ""/home/griswold/lib/python/django/forms/models.py"", line 36, in
save_instance
   raise ValueError(""The %s could not be %s because the data didn't""
ValueError: The Thing could not be created because the data didn't validate.
>>>
>>> Thing.objects.create()
<Thing: Thing object>
>>> Thing.objects.create()
<Thing: Thing object>
>>> Thing.objects.all()
[<Thing: Thing object>, <Thing: Thing object>, <Thing: Thing object>]
}}}

{{{
mysql> show create table test_thing\G
*************************** 1. row ***************************
       Table: test_thing
Create Table: CREATE TABLE `test_thing` (
  `id` int(11) NOT NULL auto_increment,
  `other_id` int(11) default NULL,
  PRIMARY KEY  (`id`),
  KEY `test_thing_other_id` (`other_id`),
  CONSTRAINT `other_id_refs_id_52a1a3a0adf89f6` FOREIGN KEY (`other_id`) REFERENCES `test_otherthing` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1
1 row in set (0.00 sec)
}}}[[BR]]
"		closed	Forms	1.0		fixed	model-validation		Accepted	1	0	0	0	0	0