Need to be able to refer to a derived table's columns

[jaypipes]

When creating a derived table by, for example, creating a subselect and joining to it:

subq := sqlb.Select(colOrgId).As("o1")

In order to join the above subquery to another table, we need to do something like this:

joinCond := sqlb.Equal(colOrgId, subq.Column("id"))
q := sqlb.Select(orgs).Join(subq, joinCond)

The problem is that SelectQuery (which is returned from the SelectQuery.As() method) does not have a Column() method and therefore we have no way to refer to the subquery's projections (columns).