Error while "saveOrUpdate" and IDs

dadom · **Joined:** Mon Sep 07, 2009 8:07 am **Posts:** 2

Hi all together,

I try to build up a little WebStart Client with two databases (local and remote), both with Hibernate Access. Now i try to create a little syncronize mechanism, for this reason i play a little bit around with the different persists-Methods of the hibernate session, and running into errors with the following code snipped:

Code:

   public void saveData(List lst) {
      Session session=sessionFactory.openSession();
      session.getTransaction().begin();
      for (Object e:lst){
         session.saveOrUpdate(e);
      }
      session.getTransaction().commit();
      session.close();
   }

The "lst"-Parameter is a list of changed objects in local database, which should be inserted or updated into the remote database:

Code:

07.09.2009 14:16:15 org.hibernate.jdbc.BatchingBatcher doExecuteBatch
SCHWERWIEGEND: Exception executing batch: 
org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1

my search for this error code bring up the fact, that this error appears if the database can't find the Object which should be edit. But that is for me a little bit strange, in my opinion i use "saveOrUpdate" exactly for this reason: if the object exists -> update, if not -> insert, but that maybe seems a misunderstanding?

Any Ideas?
Thanks for help
Dom

dadom · **Joined:** Mon Sep 07, 2009 8:07 am **Posts:** 2

Solution:

I misunderstood the mechism which hibernate use to check if he uses "insert" or "update". I thought hibernate checks the DB if ID-Fields exists or not. But thats seems to be wrong. With my latest tests hibernate just checks if the primary key in the object is set (=update) or nor (=insert).

Greets
D

Cameron McKenzie · **Posted:** Mon Sep 07, 2009 8:50 pm

Thanks for the postback! It's great to hear your finding.

Here's a little tutorial on "How Hibernate Works" that may even add more to your understanding of Hibernate and Object Relational Mappings:

http://jpa.ezhibernate.com/Javacode/lea ... rnateworks