SQLAlchemy ORM: modify the columns returned from a query

Question

If I\'ve got an SQLAlchemy ORM query:

admin_users = Session.query(User).filter_by(is_admin=True)

Is it possible to modify the columns retur

Answer 1

Assuming that your Address.user_id defines a ForeignKey, the query below will do the job more efficiently compared to IN operator:

admin_email_addresses = session.query(EmailAddress).\
    join(User).filter(User.is_admin==True)

If you do not have a ForeignKey (although you should), you can specify the join condition explicitely:

admin_email_addresses = session.query(EmailAddress).\
    join(User, User.id==EmailAddress.user_id).filter(User.is_admin==True)

But if you really would like to do it with in_ operator, here you go (note the subquery):

subq = session.query(User.id).filter(User.is_admin==True).subquery()
admin_email_addresses = session.query(EmailAddress).\
       filter(EmailAddress.user_id.in_(subq))