Question

Let’s say I have the following objects:

squirrel_table    - name   - country_of_origin   - id  nut_table   - id   - squirrel_who_owns_me[fk to squirrel] 

I want to retrieve a list of all squirrels in a particular country. The returned squirrel objects can be in a QuerySet, but do not need to be. A list will suffice. Each squirrel will have an additional property call nut_count. The SQL for this would be something like what follows (please note I use the subquery in order to not enumerate all of squirrel’s columns, since in reality there will be many) (I use PostgreSQL):

select sq.*,        nut_counts.nut_count   from squirrel_table sq,       (select sq2.id as squirrel_id,               count(nuts) as nut_count          from squirrel_table sq2,               nut_table nuts         where nuts.squirrel_who_owns_me = sq2.id           and sq.country_of_origin = 'USA'         group by sq2.id) as nut_counts  where sq.id = nut_counts.squirrel_id 

Is there a way to execute the SQL, take the cursor it generates, and turn it into a list of squirrel objects, and add the nut_count to each squirrel?

Answer 1

You probably want to read through the documentation for the ‘extra()’ method, which includes an example of a similar ‘select something else and append it onto each object’ situation.