Creating EJB 3.0 Entity Relationships - EJB 3.0 Database Persistence with Oracle Fusion Middleware 11g - page 239

em.persist(article);
columns.addArticle(article);
em.flush();
em.merge(catalog2);
catalog2.addEdition(edition);
}
Remove a catalog :
public void deleteSomeData() {
Query q = em.createNamedQuery("findCatalogByJournal");
q.setParameter("journal", "Oracle Magazine");
List list = q.getResultList();
for (Object catalog : list) {
em.remove(catalog);
}
}
Remove an edition :
public void removeEdition(Edition edition) {
List<Catalog> catalogs = edition.getCatalogs();
for (Catalog catalog : catalogs) {
catalog.removeEdition(edition);
}
em.remove(edition);
}
Remove a section :
public void removeSection(Section section) {
Edition edition = section.getEdition();
edition.removeSection(section);
em.remove(section);
}
Remove an article :
public void removeArticle(Article article) {
Section section = article.getSection();
section.removeArticle(article);
em.remove(article);
}
}