Updating a persons name using toplink uow

Question

Hi,
I am having problems updating the name of a PERSON. I am using Toplink with a SessionBeanFacade.
I am using a Backing Bean, which is calling the Session Bean Facade. I was debugging the code and the strange thing is: I can see the updated name in the entity and in the uow, but after uow.commit the updated name isn't in the database. Why won't the values from the uow persist?
SESSION BEAN FACADE
  public Object mergeEntity(Object entity) {
    UnitOfWork uow = getSessionFactory().acquireUnitOfWork();
    Object workingCopy = uow.readObject(entity);
    if (workingCopy == null)
      throw new RuntimeException("Could not find entity to update");
    uow.deepMergeClone(entity);
    uow.commit();
    return workingCopy;
BACKING BEAN
  public void recoverBusinesspartner(ActionEvent actionEvent) {
    DCBindingContainer dcBind = (DCBindingContainer)getBindings();
    DCIteratorBinding iterBind = (DCIteratorBinding)dcBind.get("personIterator");
    iterBind.getCurrentRow().setAttribute("name", "Bodhy");
    dcBind.getOperationBinding("mergeEntity").execute();
  }Thank you
Bodhy
Edited by: Bodhy on 30.09.2008 06:02
P.S. I don't get any errors or some other message in my log. I am using JDeveloper 11g TP3

Answer 1

Hello,
Glad you found the problem. As I mentioned in my previous post, you should not be modifying objects from the session cache. When you do any sort of query on a session other than a UnitOfWork, the objects returned exist in the shared session cache. When you register an object, the state of the object is pulled from the session cache and used for a comparison - TopLink will think that is the state the database is in.
This is why Detach resolves the issue- it makes a copy of the object so that changes to it do not get put into the cached copy.
I would recommend looking at:
http://www.oracle.com/technology/products/ias/toplink/doc/1013/main/_html/cachun001.htm
and
http://www.oracle.com/technology/products/ias/toplink/technical/unitOfWorkWP.pdf
to see how caching and the UOW work in TopLink
Best Regards,
Chris