Sometimes it is not enough to fetch the data as-is, but
it is necessary to add something extra to it. This can
be done by adding a computed field to the shape. Let's
fetch all the accounts and add the username length as
well as the length of their watchlist to the results:
We can even incorporate a comparison to the average username length in our computed field. There are several ways to do
this, so in this example we'll use a detached construct to denote that the Account we're referring to
in the subquery is supposed to be treated as the
original unmodified set in the database rather than the
object we're adding the data to:
