One-to-many mapping with both tables having composite-id

jeje · **Posted:** Wed Feb 11, 2004 12:03 pm

I am trying to solve the following issue :

Code:

create table B (
   businessKey NUMBER(19,0) not null,
   version NUMBER(10,0) not null,
   tbeg DATE not null,
   payload VARCHAR2(255),
   vbeg date,
   vend date,
   tend timestamp not null,
   status CHAR(1) not null,
   c_businessKey NUMBER(19,0),
   primary key (businessKey, version)
)

create table C (
   businessKey NUMBER(19,0) not null,
   version NUMBER(10,0) not null,
   tbeg DATE not null,
   payload VARCHAR2(255),
   vbeg date,
   vend date,
   tend timestamp not null,
   status CHAR(1) not null,
   primary key (businessKey, version)
)

where c_businessKey columns references C.businessKey.

The thing is C.businessKey is not unique.

What I would like to be able to do is to write a method on the object mapped to table B (let's call it BO) that would have a method getCByBusinessKey() that would return a list of CO where C.businessKey would be the one from B.c_businessKey.

I tried to map it as a list, but I does not work when I do the following for the mapping of B:

Code:

<list name="links" cascade="save-update">
  <key>
    <column name="c_businessKey"/>
  </key>
  <index column="version"/>
  <one-to-many class="com.bnpparibas.power.model.C"/>
</list>

The problem comes from the fact that CO has a composite-key so the list defined in BO must have both columns defined in the key.

What am I missing there?

emmanuel · **Posted:** Wed Feb 11, 2004 12:14 pm

You can't do it with Hibernate.
map c_businessKey as a property and do a manual HQL resquest to get your list of C

jeje · **Posted:** Wed Feb 11, 2004 12:26 pm

emmanuel wrote:

You can't do it with Hibernate.
map c_businessKey as a property and do a manual HQL resquest to get your list of C

Quite a ugly hack :-)
I would like to separate my persistence model from Hibernate.

If I understand your solution, what your suggest is to alter BO so that it has a simple long property. Then if I want to provide a method List getCByBusinessKey() on BO, I'll have to write a HQL query within this method.

Is there any technical reason why Hibernate can't handle this case, or is it only because it is not *yet* implemented?

I was thinking about replacing the composite-ids with an simple id having two columns and using a custom UserType. If I do so, will the list mapping still be wrong?