Single Table Inheritance with BDB and JPA

Question

I am using Java based BDB (4.0) and using @Entity, @PrimaryKey, etc. tags to define my model. I am using @SecondaryKey to define relationships, e.g.
@Entity
public class User {
@PrimaryKey(sequence = "ids_seq")
private int id;
@SecondaryKey(relate = Relationship.MANY_TO_ONE, relatedEntity = Department.class, onRelatedEntityDelete = DeleteAction.CASCADE)
private Integer albumID;
@Entity
public class Department {
@PrimaryKey(sequence = "ids_seq")
private int id;
@SecondaryKey(relate = Relationship.ONE_TO_MANY, relatedEntity = User.class)
private Set<Integer> userIDs;
Now, I want to extend User and apply Single Table Inheritance, e.g.
@Entity
public class Employee extends User {
Can someone suggest how to do it with BDB. Thanks.

Answer 1

You may want to take a look at the "Entity Subclasses and Superclasses" section in the javadoc:
http://www.oracle.com/technology/documentation/berkeley-db/je/java/com/sleepycat/persist/model/Entity.html
Does this help?
--mark