Django: Why create a OneToOne to UserProfile instead of subclassing auth.User?

Note: If you are tempted to 'answer' this question by telling me that you don't like django.contrib.auth, please move on. That will not be helpful. I am well aware of the range and strength of opinions on this matter.

Now, the question:

The convention is to create a model, UserProfile, with a OneToOne to User.

In every way I can think of, a more efficient and effective approach is to subclass User to a class that one intends to use for every human in the system - a class called, say, Person(User).

I have not seen a coherent explanation of why the former is conventional and the latter is regarded as a hack. A while ago, I changed over to the OneToOne approach so as to gain the ability to use get_profile() and I have regretted it ever since. I'm thinking of switching back unless I can be made to understand the advantage of this approach.

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You do realise, don't you, that model subclassing is implemented by means of a OneToOne relationship under the hood? In fact, as far as efficiency is concerned, I cannot see any difference at all between these two methods.

Subclassing of existing concrete models is, in my opinion, a nasty hack that should be avoided if at all possible. It involves hiding a database relationship so that it is unclear when extra db access is performed. It's much clearer to show the relationships explicitly, and access them explicitly where necessary.

Now, a third alternative which I do like is to create a completely new User model, along with a custom authentication backend that returns instances of the new model instead of the default one. Creating a backend only involves defining a couple of simple methods, so it's very easy to do.

answered 2011-03-27T20:56:54.410

Django: Why create a OneToOne to UserProfile instead of subclassing auth.User?

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