Question

I have 2 django models like this:

class UserProfile(models.Model):
    user             = models.OneToOneField(User)
    organisation     = models.CharField(max_length=200)

class Submission(models.Model):
    user             = models.ForeignKey(User)
    date_submission  = models.DateTimeField(db_index=True, default=datetime.now())
    date_published   = models.DateTimeField(db_index=True, null=True)
    status           = models.CharField(db_index=True, max_length=4000)
    logfile          = models.TextField(db_index=False)

where each ‘Submission’ object is owned by a normal django user, and each user has a UserProfile configured using the AUTH_PROFILE_MODULE in the normal way.

This works as you would expect, i can see the organisation field of the UserProfile object:

Submission.objects.all()[0].user.userprofile.organisation

When i want to serialize the Submissions list (for export to json) normally i use:

Submission.objects.all().values()
# or for more control of fields
Submission.objects.all().values('status', 'date_submission')
# to traverse a relationship.. get info from the User object
Submission.objects.all().values('user__username')

.. these work fine. BUT my problem is that i cannot:

Submission.objects.all().values('user__userprofile__organisation')

raise FieldError("Invalid field name: '%s'" % name)
django.core.exceptions.FieldError: Invalid field name: 'user__userprofile__organisation'

so it seems that the UserProfile is a ‘special case’. This was discussed here:
Django query : Call values() on user__userprofile

but the solution doesn’t help me (i’m fairly sure..)

Is this a limitation of the values() method ? does anyone know a way to get the same output of values() but able to traverse the UserProfile model ?

thanks for any ideas

-i

Answer 1

Turns out upgrading to version 1.4 of Django solved the problem, the comment by Jingo suggests 1.3.1 would also be ok.

so now i can:

query_set = Submission.objects.filter()
query_set.values('user__userprofile__organisation')
[{'user__userprofile__organisation': u'organisation test 1'}]

cheers

-i