hibernate执行sql获取泛型对象
看下面的SQL查询示例：
private void test()
{
//获取Hibernate Session对象
Session session = HibernateUtil.currentSession();
//开始事务
Transaction tx = session.beginTransaction();
//编写SQL语句
String sqlString = “select {s.*} from student s where s.name like ‘马军’”;
//以SQL语句创建SQLQuery对象
List l = session.createSQLQuery(sqlString)
//将查询到的记录与特定实体关联起来
.addEntity(“s”,Student.class)
//返回全部的记录集
.list();
//遍历结果集
Iterator it = l.iterator();
while (it.hasNext())
{
//因为将查询结果与Student类关联，因此返回的是Student集合
Student s = (Student)it.next();
Set enrolments = s.getEnrolments();
Iterator iter = enrolments.iterator();
while(iter.hasNext())
{
Enrolment e = (Enrolment)iter.next();
System.out.println(e.getCourse().getName());
}
}
//提交事务
tx.commit();
//关闭Session
HibernateUtil.closeSession();
}
上面的示例显示了将查询记录关联成一个实体的示例。事实上，SQL查询也支持将查询结果转换成标量值，转换成标量值可以使用addScalar方法，如：
Double max = (Double) session.createSQLQuery(“select max(cat.weight) as maxWeight from cats cat”)
.addScalar(“maxWeight”, Hibernate.DOUBLE);
.uniqueResult();