access to old data when updating with Home component

[i92jurir]

Hi all,

I have to copy old data of one entity to a auditing table when someone update the entity. I have overriden the update method of the Home component of the entity.

@Override
    public String update() {
        
        // get current data in db   NOT WORKING 2 WAYS
        Person old = entityManager.find(Person.class, this.instance.getId());    
        Person old = (Person) entityManager.createQuery("select p from Person p where p.id = "+ instance.getId()).getSingleResult();
        
        // create new row in auditing table   OK WORKING
        Person_Auditing person = new Person_Auditing();                               
        person.setEntityData(old.getEntityData());
        entityManager.persist(person);
        
        // Make the update of the entity in database
        return super.update();

}

My problem is when I retrieve current data from database I get data already modified. I can´t get old value to copy to auditing table. Anybody can help me?

Thanks in advance.

[i92jurir]

I think the first post it´s a bit confusing.

The idea was reread the original data from a row in a update operation. I was trying override the update method of the Home component to read the data from the table. Finally It´s working.

@Override
    public String update() {

          // save modified data from instance
          MyEntity modifiedEntity = new Entity();
          modifiedEntity.setAttrib1(instance.getAttrib1());
          .......
          .......

          // recover row from database
          MyEntity currentEntity = new Entity();
          currentEntity.setId(modifiedEntity.getId());
          currentEntity = entityManager.merge(currentEntity);
          entityManager.refresh(currentEntity);

          // create audit row with current data 
          MyEntityAudit entityAudit = new MyEntityAudit(currentEntity);
          entityManager.persist(entityAudit);

          // record modified data to database
          currentEntity.setAttrib1(modifiedEntity.getAttrib1)
          .......
          .......

          return super.update();

}

Other better method to do the same thing? Thanks.