title: Django ORM how to Round an Avg result
body: <p>I have a model in which I use Django ORM to extract Avg of values from the table. I want to Round that Avg value, how do I do this?</p>
  
  <p>See below I am extracting Avg price from Prices model grouped by date in format YYYY-MM, I want to automatically extract the average values rounded to the closest number.</p>
  
  <pre><code>rs = Prices.objects.all.extra(select={
      'for_date': 'CONCAT(CONCAT(extract( YEAR from for_date ), "-"),
          LPAD(extract(MONTH from for_date), 2, "00"))'
      }).values('for_date').annotate(price=Avg('price')).order_by('-for_date')
  </code></pre>