hql中new对象查询特点

在Hibernate的hql语句中可以用例如select new com.domain.User(name,passwd) from Users形式

    String hql = " select new com.domain.User(name,passwd) from Users";       
    Query query = session.createQuery(hql);    //默认查询出来的list里存放的是一个Object数组，但是在这里list里存放的不再是默认的Object数组了，而是User对象了           
    List<User> users = query.list();              

    for(User user : User){                   
       String name = user.getUsername();        
       String passwd = user.getPassword();         
       System.out.println(name + " : " + passwd);         
     } 

代码引用的是网游的代码，在开发一般查询这种方式用的不多，在多表查询时用处会挺大，做个备忘吧 呵呵

评论

2 楼 刘浩4611 2011-08-05  

SELECT new com.domain.User  
(  
TRIM(class.id),   
 
TRIM(school.id)  
)  
FROM Class class, School school  
WHERE (1 = 1)   
     AND (class.id = school.classid)  
ORDER BY class.id

1 楼 mib168 2010-11-02  

多表查询实例

      SELECT new com.domain.User
		   (
				TRIM(class.id), 
				
				TRIM(school.id)
		   )
		   FROM Class class, School school
		   WHERE (1 = 1) 
		   	 AND (class.id = school.classid)
		   ORDER BY class.id