create named query

Tue Apr 20, 2010 5:21 pm

Following code show you how to create a named query within your code (Not at orm.xml when u r are working on application server ) , Am creating here a named query using enhanced query or what it is named EJB-QL .

Code:: package com.codemiles.jpa; import java.util.List; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.Persistence; public abstract class JPAService { private EntityManager entityManager; /** * @param args */ public void showTopics() { EntityManagerFactory factory = Persistence .createEntityManagerFactory("persistenceUnitName"); entityManager = factory.createEntityManager(); entityManager.getTransaction().begin(); List<Topic> list = loadAllTopics(); if (list != null) { for (Topic currentTopic : list) { System.out.println("Topic id#(" + currentTopic.getId() + " ). Title = " + currentTopic.getTitle() + " , Content = " + currentTopic.getContent()); } } entityManager.getTransaction().commit(); entityManager.close(); factory.close(); } public List<Topic> loadAllTopics() { List<Topic> resultList = entityManager.createQuery( "SELECT t FROM Topic t").getResultList(); return resultList; } public Topic loadAllTopicsById(int id) { return (Topic) entityManager.createQuery( "SELECT t FROM Topic t.id=" + id).getSingleResult(); } }