Hibernate之Query介面的uniqueResult()方法
阿新 • • 發佈:2019-02-12
如果查詢返回多個值用list()方法
當確定返回的例項只有一個或者null時 用uniqueResult()方法public void testQuery(){ Configuration config = new Configuration().configure(); SessionFactory factory = config.buildSessionFactory(); //建立SessionFactory Session session = factory.openSession(); //建立Session session.beginTransaction(); //開始事務 Query query = session.createQuery("from Student"); List list = query.list(); // 用list方法返回多個值 //List list = session.createQuery("from Student").list(); for(int i=0;i<list.size();i++){ Student student = (Student)list.get(i); System.out.print(student.getId()+" "); System.out.print(student.getName()+" "); System.out.print(student.getSex()+" "); System.out.print(student.getBirthday()); System.out.println(); } session.getTransaction().commit(); //提交事務 session.close(); //關閉Session }
public void testGet(){ Configuration config = new Configuration().configure(); SessionFactory factory = config.buildSessionFactory(); Session session = factory.openSession(); session.beginTransaction(); Query query = session.createQuery("from Student s where s.id=?"); query.setString(0, "2"); Student student = (Student)query.uniqueResult(); //當確定返回的例項只有一個或者null時 用uniqueResult()方法 //Student student = (Student)session.createQuery("from Student s where s.id=?").setString(0,"5").uniqueResult(); System.out.println(student.getName()); System.out.println(student.getBirthday()); session.getTransaction().commit(); session.close(); }