Question

I need to make a request on the model himself :

class Course(models.Model):
    owner = models.ForeignKey(User, related_name='course', limit_choices_to={'userprofile__status': 'teacher'})

class Assignment (models.Model):
    course = models.ForeignKey(Course, related_name='assignment')
    admins = models.ManyToManyField(User, blank=True, null=True, limit_choices_to={'userprofile__status': 'teacher'})

I need admin contain all users (with teacher as status) without the owner. I have tried with Q objects but it was not a success…

Answer 1

I’m not sure if you can do this right on the model, but if you could it would be done with F. Something like:

from django.db.models import Q, F

...

limit_choices_to=Q(userprofile__status='teacher') & ~Q(id=F('owner_id'))

You have to use Q because you can’t assert a negative with the dictionary pattern. The ~ negates the second Q and F('owner_id') is use to select the value for owner.

Like I said, though, I haven’t tried to do this myself, so I can’t say if it will work or not. You’ll just have to give it a whirl and let us know.