title: django - Dynamically add computed column to queryset
body: <p>I have a database table containing 4 integer columns representing version information - Major, Minor, Cust, Rev.</p>
  
  <p>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].</p>
  
  <p>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:</p>
  
  <pre><code>queryset = MyModel.objects.all()
  </code></pre>
  
  <p>...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.</p>