sqlalchemy select_from

While join() exclusively deals with the “right” side of the JOIN, we can also control the “left” side, in those cases where it’s needed, using select_from(). Below we construct a query against Address but can still make usage of User.addresses as our ON clause by instructing the Query to select first from the User entity:

q = session.query(Address).select_from(User).\
                join(User.addresses).\
                filter(User.name == 'ed')

Which will produce SQL similar to:

SELECT address.* FROM user
    JOIN address ON user.id=address.user_id
    WHERE user.name = :name_1