Hi,

I have a Parent class and two children - ChildA and ChildB - classes.
I need to map these to three tables - PARENT, CHILDA and CHILDB.
PARENT to CHILDA is an optional one-to-one relation.
PARENT to CHILDB is an optional one-to-many relation.
I am able to map ChildA with a joined-subclass, and it works fine.

How do I map the ChildB? The primary key of the CHILDB contains the primary key of the PARENT, and another column(say SEQ_NUM).

Thanks, LinHib.

XML Mapping:
http://www.hibernate.org/hib_docs/v3/re ... tance.html

And if you're using Annotations/JPA:
http://www.hibernate.org/hib_docs/annot ... tml#d0e829

Always be sure to check the docs ;)
If this helps, would you do me a favor and mark the post helpful below? Thanks,
- TK

I am using the "table per subclass" strategy for the PARENT-to-CHILDA relation, and it works.

But I am not able to use the same for PARENT-to-CHILDB relation since the primary key of CHILDB is not the same as the primary key of the PARENT. The primary key of CHILDB is (PARENT_ID, SEQ_NUM), where as the primary key of the PARENT is PARENT_ID alone.

class Parent {
Long parentId;
}

class ChildB extends Parent {
Collection<ChildBElement>;
}

class ChildBElement {
Long seqNum;
...
}

I defined a joined-subclass for CHILDB with key as PARENT_ID. Added a bag for the collection, with key as the SEQ_NUM. Now hibernate tries to insert a record into CHILDB with only PARENT_ID, and fails since SEQ_NUM is not nullable:
Generated SQL: insert into CHILDB (PARENT_ID) values (?)

It doesn't insert SEQ_NUM and other values in the ChildBElement. What am I doing wrong?

Thanks, LinHib.

Cheak that you are cascading from bag.can you tell exactly what is the exception you are getting