Django Multi-Table Inheritance VS Specifying Explicit OneToOne Relationship in Models

Question

Hope all this makes sense :) I\'ll clarify via comments if necessary. Also, I am experimenting using bold text in this question, and will edit it out if I (or you) find it distr

Answer 1

I recently switched over to using models that inherit off of contrib.auto.models.User. My general observation is that in theory they're great, but sometimes they don't get auto-magically handled like they're supposed to.

I think your decision regarding inheritance vs. OneToOne comes down to this:

• Do I want to have Django automatically do something right 95% of the time, and need to debug that other 5%

-OR-

• Do I want to do something manually myself 100% of the time

If you haven't seen it, the Scott Barham blog has a great post about inheriting off of User, and also building a custom back end to make sure that your custom object is being returned -- Extending the Django User.

Additionally of interest would be the AutoOneToOne field provided by django-annoying. It's sort of a hybrid of the two approaches here -- there's no inheritance taking place, but Django is taking care of creating the matching OneToOneField if it's not present.

Also, thornomad does make a good point about the redundancy in your models. You could easily implement an abstract class to clean that up as so (assuming you're doing manual OneToOne):

class BaseExtendedUser(models.Model):
    user = models.OneToOneField(User, blank=True, related_name='profile')
    landline = models.CharField(blank=True, max_length=20)    
    mobile = models.CharField(blank=True, max_length=20)
    created_by = models.ForeignKey(User, editable=False, blank=True, related_name="created_users")    
    modified_by = models.ForeignKey(User, editable=False, blank=True, related_name="modified_users")

    class Meta:
        abstract = True

class Administrator(BaseExtendedUser):
    province = models.ForeignKey(Province)

class Principal(BaseExtendedUser):
    branchoffice = models.ForeignKey(BranchOffice)