Django: Accessing child class of an abstract model

Question

I have several user profile models inherited from one base class like this:

class BaseProfile(models.Model):
    user = models.ForeignKey(User)
    name = models.CharField(max_length=100)
    ...
    class Meta:
        abstract = True

class DoctorProfile(BaseProfile):
    license_no = models.CharField(max_length=10)
    ...

class PharmacistProfile(BaseProfile):
    pass

When I have a user instance, I would like to get their profile.

I don't feel like checking if the user has a profile one by one with sth. like this:

if user.doctorprofile_set.all().count() == 1:
    return user.doctorprofile_set.all()[0]
elif user.pharmacistprofile_set.all().count() == 1:
    return user.pharmacistprofile_set.all()[0]
...

for each profile is the best way as it is not DRY and requires extra queries on database.

What is the best way to do this?

edit: would be nice to define AUTH_PROFILE_MODULE in settings to point to the base model like AUTH_PROFILE_MODULE = 'profiles.baseprofile' and be able to use user.get_profile() on every user with different profile classes derived from the same base profile.

Answer 1

Make it a OneToOneField instead of a FK then do user.doctorprofile etc. The OneToOne will throw an Foo.DoesNotExist or Foo.MultipleObjectsReturned, though, if things go wrong, so be prepared to catch those exceptions