Hibernate之Query介面的uniqueResult 方法
阿新 • • 發佈:2018-12-22
如果查詢返回多個值用list()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
}
當確定返回的例項只有一個或者null時 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(); //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();
}
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