mapping object hierarchy with @Inheritance(strategy=JOINED)

kristian · **Posted:** Tue Mar 13, 2007 9:40 am

Hi all,

i'm trying to map following object tree with table per class hierarchy
AND Joined subclasses strategy, but i always get table per class
hierarchy

Code:

A(name) -> B1(name)
        -> B2(name)
        -> B3(name) -> C1(ref)
                    -> C2(type)

so i defined my classes as :

Code:

@Entity
@DiscriminatorColumn(
        name="access_type",discriminatorType=DiscriminatorType.STRING
    )
@DiscriminatorValue("a-type")
@Table(name="a")
public abstract class A  { ... }

B1 and B2 are straight forward:

Code:

@Entity
@DiscriminatorValue("b1")
public class B1 extends A  { ... }

@Entity
@DiscriminatorValue("b2")
public class B2 extends A  { ... }

as i want to have separate tables for C1 and C2
i add @Inheritance(strategy=InheritanceType.JOINED)
to my B3 object

Code:

@Entity
@Inheritance(strategy=InheritanceType.JOINED)
public abstract class B3 extends A  { ... }

C1 and C2 then extend from B3

Code:

@Entity
public abstract class C1 extends B3  { ... }

@Entity
public abstract class C2 extends B3  { ... }

When i test this i always get a single table for both hierarchies (B and C)
because the discriminator is inherited from the base class A.

Is there a way i can save my C objects in separate tables?
After reading the documentation i'm wondering whether i should use a @SecondaryTable, or a @OneToOne, or even @MappedSuperclass

I'd appreciate any hint :)
Thank you!

g,
kris

Hibernate version:
3.2.1.ga

Name and version of the database you are using:
HSQLDB 1.8.0.7

emmanuel · **Posted:** Tue Mar 13, 2007 6:49 pm

you can map that using a @SecondaryTable(s)

kristian · **Posted:** Thu Mar 15, 2007 6:33 am

thank you, i'll try this...