Update object problem

Question

Hi!
I'm having some problems to update an object using TopLink with OracleXE.
I have been traying different things with the merge method in the UnitOfWork API. The code executes without problems, but the rows in the databaste keep untouched as before.
Any idea?
Thanks,
Claudio
This is my code:
Session sess=DBManager.getInstance().getSession();
          List objects=sess.readAllObjects(Sector.class);
          Sector sec=(Sector)objects.get(0);
          sec.setNombre("Contenedores"); //Changing name to "Contenedores"
          GrupoDeTrabajo grupo = (GrupoDeTrabajo) sec.getGruposDeTrabajo()
                    .get(0);
          sec.removeFromGruposDeTrabajo(grupo); //removing the first child
          grupo = (GrupoDeTrabajo) sec.getGruposDeTrabajo().get(0); //Retriving the next child
          grupo.setNombre("Other group"); //changing name of one child of sec
          UnitOfWork uow=DBManager.getInstance().getSession().acquireUnitOfWork();
          Object workingCopy = uow.readObject(Sector.class);
          if (workingCopy == null || workingCopy==sec) {
                    throw new DBException();
          uow.validateObjectSpace();
          uow.printRegisteredObjects();
          uow.mergeCloneWithReferences(sec);
          uow.writeChanges();
          uow.commit();
          uow.release();

Answer 1

You cannot change objects you read through the TopLink Session. These objects must be read-only. You can only modify registered clones in a UnitOfWork.
i.e.
Session sess=DBManager.getInstance().getSession();
List objects=sess.readAllObjects(Sector.class);
UnitOfWork uow=DBManager.getInstance().getSession().acquireUnitOfWork();
Sector sec=(Sector)uow.registerObject(objects.get(0));
sec.setNombre("Contenedores"); //Changing name to "Contenedores"
GrupoDeTrabajo grupo = (GrupoDeTrabajo) sec.getGruposDeTrabajo()
.get(0);
sec.removeFromGruposDeTrabajo(grupo); //removing the first child
grupo = (GrupoDeTrabajo) sec.getGruposDeTrabajo().get(0); //Retriving the next child
grupo.setNombre("Other group"); //changing name of one child of sec
uow.commit();
The merge API is for objects that are serialized to a remote client and back.