Consider the following query :

from Branch branch where branch.state='AZ' and branch.branchId in
(select office.Branch from Office office where office.division='MN')

Background :

Branch and Office have a one to many relactionship.

Suppose a Branch object has a set of Offices and - because of
the bi-directional hbm mapping - an Office has a Branch object.

The HQL statement selects Branch objects having an Office
object having division='MN'


Questions :

1. Is this an efficient query?

2. Is there a better alternative to this query which returns
the same result?

(This query appears crude given all the clean ways Hibernate
offices to create queries. )

3. Is there a join style way to create this query? Sort of like

from Branch branch where branch.state='AZ'
and branch.offices.division='MN'

4. Is there a way to do this without using a bi-directional mapping?

Many thanks.