Hello,

I am having a problem with the @Version tag in combination with a timestamp (mysql5, hibernate 3.2.2)


I have a simple bean with id, name and version attributes.

The following code fragment

EntityManagerFactory emf = Persistence.createEntityManagerFactory(System.getProperty("EntityManager"));
EntityManager em=emf.createEntityManager();
EntityTransaction tx1=em.getTransaction();
tx1.begin();
Role r1=new Role();
r1.setName("role");
em.persist(r1);
tx1.commit();
em.clear();
EntityTransaction tx2=em.getTransaction();
tx2.begin();
r1=em.merge(r1);
em.remove(r1);
tx2.commit();

When I have a int @Version attribute the code seems to work fine, but with a Timestamp version I get

javax.persistence.OptimisticLockException: org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [com.luma.w2p.model.Role#5]
at org.hibernate.ejb.AbstractEntityManagerImpl.wrapStaleStateException(AbstractEntityManagerImpl.java:645)
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:599)
at org.hibernate.ejb.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:236)


Is there something wrong with the code? Or is this a (known) issue in Hibernate (the glassfish/toplink ri) also works for Timestamp version attribute.

Thanks,

Peter

check how the timestamp is stored into the db. it has probably changed somehow

It looks like it yes. If I fetch the version timestamp column the nano's part is gone, while the version attribute in the Role does contain it.

Unfortunately that does not really bring me much closer to a solution. My closest guess is that something is wrong with the jdbc and/or mysql installation/configuration.

Anyone any (other) thoughts?

Thanks!

Peter

As a workaround you could subclass TimestampType and change isEqual() to behave like Toplink, ie ignore the nano's part and use @Type. Kinda sucks but at least it will work

Thanks for your help. I'll probably stick with integers instead...or switch databases.