Hibernate之Query接口的uniqueResult()方法详解编程语言

public void testQuery(){ 

 Configuration config = new Configuration().configure(); 

 SessionFactory factory = config.buildSessionFactory(); //创建SessionFactory 

 Session session = factory.openSession(); //创建Session 

 session.beginTransaction(); //开始事务 

 Query query = session.createQuery("from Student"); 

 List list = query.list(); // 用list方法返回多个值 

 //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(); //提交事务 

 session.close(); //关闭Session 

当确定返回的实例只有一个或者null时 用uniqueResult()方法

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(); //当确定返回的实例只有一个或者null时 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()); 


 }

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