Selecting specific fields in JPA Queries

Question

I am using Hibernate JPA implementation org.hibernate:hibernate-entitymanager:3.4.0.GA at central maven repo. I have two classes.

Class A extends Class B

When I execute a query like "SELECT b FROM B b", the result list, as expected, contains Class A instances too.

Is there a way to retrieve only the Class B instances without any fields from Class A or retrieve objects with fields only belonging to class B.