Hi there,

I'm testing a small app while trying to learn Java Persistence . Just a newbie at this...

In my first unit of work I create and persist a ScheduledCourse object like so:

EntityManagerFactory emf = Persistence.createEntityManagerFactory("scholastic");

//First Unit of work
EntityManager em1 = emf.createEntityManager();
EntityTransaction tx1 = em1.getTransaction();
tx1.begin();
...
ScheduledCourse scheduled_course = new ScheduledCourse(...);
...
em1.persist(scheduled_course);
...
tx1.commit();
em1.close();
emf.close();

Up to this point everything is fine.
In my second unit of work I try to remove the instance of that object from the database:

EntityManagerFactory emf2 = Persistence.createEntityManagerFactory("scholastic");
EntityManager em2 = emf2.createEntityManager();
EntityTransaction tx2 = em2.getTransaction();
tx2.begin();
...
//Retrieve the entity instance from the dbase and make it persistent again
ScheduledCourse sc = em2.find(ScheduledCourse.class, new Long(1));
...
em2.remove(sc);
...
tx2.commit();
em2.close();
emf2.close();

When the delete is attempted, I get this error message:

[java] Could not synchronize database state with session
[java] org.hibernate.exception.GenericJDBCException: Could not execute JDBC batch update

Could someone please explain what I may have done wrong? Why isn't the deletion occurring properly?

Alan

you do not provide enough information, also there is no need to create several time the emf, it should be cached somewhere