Hibernate_CriteriaAPI.txt

JPA Criteria
	SQL/HQL queries can become complex to maintain
	Java developers have to learn SQL/HQL to perform queries
	JPA Criteria helps to avoid quries using Criteria API
	The JPA Criteria provides methods to add criteria, so it is easy for the java programmer to add criteria.
	
	
e.g.
	SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
	Session session = sessionFactory.openSession();
	session.beginTransaction();
	
	//get criteria builder
	CriteriaBuilder cb = session.getCriteriaBuilder();
	
	//create criteria for an entity
	CriteriaQuery<User> criteria = cb.createQuery(User.class);  
	
	//set the root
	Root<User> root = criteria.from(User.class);
	
	//set selects and criterion
	criteria.select(root); //set selects
//		criteria.select(root.get("userName")); //selects only userName field
	criteria.where(cb.equal(root.get("userName"), "User With Where"));
	
	//execute the query
	List userList = session.createQuery(criteria).getResultList();
	
	System.out.println("users = " + userList);
	
	session.getTransaction().commit();
	session.close();