Entitymanager

I’m trying to use OpenJPA to insert some entries in the database and I’m getting a strange number of UPDATEs beside the INSERTs. I isolated the problem to the following snippet of code private void start() { EntityManagerFactory emf = Persistence.createEntityManagerFactory("persistencexmltest1PU"); EntityManager em = emf.createEntityManager(); for (int i = 0; i < 10; i**) { em.getTransaction().begin(); MyEntity n =new MyEntity(); n.setValue(i); em.persist(n); em.getTransaction().commit(); } } The generated SQL looks like this: ...

I really want to talk about JTable, Beans Binding and JPA pagination but I think I need to write about JTable and JPA pagination first. So I will take the Beans binding stuff in another post. By the way, choose wisely your JPA Provider/DB Provider combination, as some combinations will not give you any real paginations at all. For example, neither OpenJPA, Hibernate or TopLink/EclipseLink seems to support Apache Derby pagination (OFFSET/FETCH). The example here uses Derby and TopLink which is a bad example because the JPA pagination doesn’t get translated to SQL command for pagination. So if you really want proper pagination you should use other combination like Hibernate JPA/HSQLDB. ...