django - Dynamically add computed column to queryset

Question

I have a database table containing 4 integer columns representing version information - Major, Minor, Cust, Rev.

I'd like to represent these as a single column in my form, with relevant padding. So: 0, 1, 2, 3 = [0.01.002.0003].

I realise that there are several ways to use SQL to do this, but I'm curious as to whether it's possible to do it on the django side? So, after:

queryset = MyModel.objects.all()

...can I then extend the queryset with an additional calculated field? Later I pass the Queryset to be serialized, and I need the calculated field present at this stage, so I don't think an attribute will work.

Answer 1

annotate should help you:

http://docs.djangoproject.com/en/dev/ref/models/querysets/#annotate-args-kwargs