Question

I use JPA to add data to Derby DB with eclipse link and when there is duplicated ID.

I got error, there is a way in run-time (with code) to simple delete all the table entries.

I don’t need the old entry just new entries in every time that I invoke the program.

I tried with

factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME);
EntityManager entityManager = factory.createEntityManager();

entityManager.getTransaction().begin();

Query query = entityManager.createQuery("SELECT p FROM Job p ");

List resultList = query.getResultList();

for (Object result : resultList) {
    entityManager.remove(result);
}

entityManager.getTransaction().commit();
entityManager.close();

but here I use query before and I don’t want to do that I want to delete all the entries and I don’t care what is there before.

Answer 1

You can use the SQL DELETE query at runtime everytime the application starts. If you don’t post some code, we can’t help.

EDIT :

You can execute the query as follows in some earlier transaction or the same transaction before the query:

int deletedCount = entityManager.createQuery("DELETE FROM Job").executeUpdate();