Composite primary keys are great and relating two records together is best done using them. Adding another field just to identify the relationship makes the table un-normalized (that isn’t a word is it?) and we all want our tables normalized don’t we? So it is common practice for (good) database designs to use them anywhere two records are being related.

Unfortunately Django doesn’t support them right now, at least not without some nasty hacks. This means every time you get your hands on a legacy database there is a high likelihood that there will be composite primary keys are in use and you will be in for a world of pain if you wish to integrate it with Django. I’ve been there and the hacks are nasty, and also mean you can’t use a lot of components such as the admin which makes me sad as the admin is a beautiful thing.

The ticket (http://code.djangoproject.com/ticket/373) has been around for 5 years with only one person taking a decent crack at it and he seems to have stopped working on it around the same time the core team was working on 1.0. So I have started on the path of getting Django to support them. And this doesn’t just mean working on the ORM part of Django, it means getting every part of Django to understand that a primary key doesn’t just mean one column/field. Not a small project by any means but it will show some pay-offs in the short term as it replaces the hacks I currently have in place.

Once I have some code to show it will be up on my github http://github.com/hartror