You need to also state that null=True. Also, you want to have ensure that the field defined in your db allows null values.
On Mon, Jun 28, 2010 at 3:19 PM, Jonathan Hayward < [email protected]> wrote: > I have a model with two foreign keys to itself: > > department = models.ForeignKey(u'self', blank = True, related_name = > u'member') > reports_to = models.ForeignKey(u'self', blank = True, related_name = > u'subordinate') > > When I tried to save test data from the admin interface, leaving those > items blank, I got a ValueError, pasted below. What do I need to be able to > save test data? I'm willing to assign non-blank values to those fields for > now, but there's a chicken-and-egg problem if the admin interface won't let > me save any instances until I already have an instance saved. > > ValueError at /admin/directory/entity/add/ > > Cannot assign None: "Entity.department" does not allow null values. > > Request Method: POST Request URL: > http://linux:8000/admin/directory/entity/add/ Exception Type: ValueError > Exception > Value: > > Cannot assign None: "Entity.department" does not allow null values. > > Exception Location: > /usr/lib/pymodules/python2.6/django/db/models/fields/related.py > in __set__, line 269 Python Executable: /usr/bin/python Python Version: > 2.6.5 Python Path: ['/home/jonathan/directory', > '/usr/local/lib/python2.6/dist-packages/pip-0.6.3-py2.6.egg', > '/home/jonathan/store/src/satchmo/satchmo/apps', > '/usr/local/lib/python2.6/dist-packages/django_threaded_multihost-1.3_3-py2.6.egg', > '/usr/local/lib/python2.6/dist-packages/django_signals_ahoy-0.1_1-py2.6.egg', > '/usr/local/lib/python2.6/dist-packages/django_tagging-0.3.1-py2.6.egg', > '/usr/lib/python2.6', '/usr/lib/python2.6/plat-linux2', > '/usr/lib/python2.6/lib-tk', '/usr/lib/python2.6/lib-old', > '/usr/lib/python2.6/lib-dynload', '/usr/lib/python2.6/dist-packages', > '/usr/lib/python2.6/dist-packages/PIL', > '/usr/lib/python2.6/dist-packages/gst-0.10', '/usr/lib/pymodules/python2.6', > '/usr/lib/python2.6/dist-packages/gtk-2.0', > '/usr/lib/pymodules/python2.6/gtk-2.0', > '/usr/local/lib/python2.6/dist-packages'] Server time: Mon, 28 Jun 2010 > 15:13:53 -050 > > -- > → Jonathan Hayward, [email protected] > → An Orthodox Christian author: theology, literature, et cetera. > → My award-winning collection is available for free reading online: > ☩ I invite you to visit my main site at > http://JonathansCorner.com/<http://jonathanscorner.com/> > > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<django-users%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/django-users?hl=en. > -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
