Here is simple example I've created after reading several topics about jpa bulk inserts, I have 2 persistent objects User, and Site. One user could have many site, so we have one to many relations here. Suppose I want to create user and create/link several sites to user account. Here is how code looks like, considering my willing to use bulk insert for Site objects.
User user = new User("John Doe");
user.getSites().add(new Site("google.com", user));
user.getSites().add(new Site("yahoo.com", user));
EntityTransaction tx = entityManager.getTransaction();
tx.begin();
entityManager.persist(user);
tx.commit();
But when I run this code (I'm using hibernate as jpa implementation provider) I see following sql output:
Hibernate: insert into User (id, name) values (null, ?)
Hibernate: call identity()
Hibernate: insert into Site (id, url, user_id) values (null, ?, ?)
Hibernate: call identity()
Hibernate: insert into Site (id, url, user_id) values (null, ?, ?)
Hibernate: call identity()
So, I means "real" bulk insert not works or I am confused?
Here is source code for this example project, this is maven project so you have only download and run mvn install to check output.