Good usage to update an object

magic · **Posted:** Sun Feb 06, 2005 5:57 pm

Hibernate version: Hibernate 3.0 beta3

What the good way to do that (i just wrote the logic of my business) :

Code:

open hibernate session

while true
  component = read data from a stream
  storedComponent = query to check if the read component already exists
  if component is new
    session.save(component)
  else
    i have to update the component data and store it into database
    (my question comes here)
  endif
  flush hibernate session
end while

? close hibernate session ?

My component has a collection of A (and each A has a collection of B). How update my stored component to correctly consider all A and B children ? :
storedComponent.getAs().removeAll();
storedComponent.getAs().addAll(component.getAs());
With this code, i'll have many B orphans, and the autoincrement of B will grow up quickly.

Any idea ? (i hope to be clear ;-)

gavin · **Posted:** Sun Feb 06, 2005 6:11 pm

session.saveOrUpdate()

magic · **Posted:** Sun Feb 06, 2005 6:31 pm

Ok, so i do that:

// id contains the primary key used by hibernate
readComponent.setId(storedComponent.getId());
session.saveOrUpdate(readComponent);

and all children (and children of children) will be removed (i configured cascade="delete-all-orphan" for one-to-many), and the new one will be added. I've right ?

magic · **Posted:** Sun Feb 06, 2005 6:54 pm

Apparently, i have wrong :-/

org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session

rotrot · **Joined:** Tue Jan 25, 2005 8:37 am **Posts:** 2

I have the same problem now myself...

magic · **Posted:** Thu Feb 17, 2005 3:48 pm

I had the object get from hibernate and an other 'image' of this object read from an external stream. I had merge data from the 'streamed' object onto the persitent object, then i updated the persistent object. Now works fine.