hibernate两表级联查询语句

一.两个表: 
person 
1 id 
2 name(人名) 
3 roomid 

room 
1 roomid 
2 room(房间号) 

说明:一个room有多个person,通过roomid取出name和room封装到list 

二.两个类: 
person类 

private int id; 
private String name; 
private int roomid; 

public Person() 
{ 

} 

public Person(int id,String name,int roomid) 
{ 
     this.id=id; 
     this.name=name; 
     this.roomid=roomid; 
} 

public int getId() 
{ 
     return this.id; 
} 

public void setId(int id) 
{ 
     this.id = id; 
} 

public String getName() 
{ 
     return this.name; 
} 

public void setName(String name) 
{ 
     this.name = name; 
} 

public int getRoomid() 
{ 
     return roomid; 
} 

public void setRoomid(int roomid) 
{ 
     this.roomid = roomid; 
} 


room类 

private int roomid; 
private String room; 

public Room() 
{ 

} 

public Room(int roomid,String room) 
{ 
this.roomid=roomid; 
this.room = room; 
}

public String getRoom() 
{ 
return this.room; 
} 

public void setRoom(String room) 
{ 
this.room = room; 
} 

public int getRoomid() 
{ 
return roomid; 
} 

public void setRoomid(int roomid) 
{ 
this.roomid = roomid; 
} 



三.Person.hbm.xml和Room.hbm.xml正常配置,此处就不写了. 



四.Hibernate语句 

String queryString="select p.name , r.room from Person p , Room r 
where p.roomId = r.roomId"; 

return getHibernateTemplate().find(queryString); 

此处返回一个list 

五.获取list的值 

设返回值是list 
写一个JavaBean: 
NrUtil 
private String name; 
private String room; 

List<NrUtil> nrUtilList; 

取list中的数据放入JavaBean中 

Iterator it=list.iterator(); 
while(it.hasNext()) 
{ 
     Object[] ob=(Object[])it.next(); 
     String name=(String)ob[0]; 
     String room=(String)ob[1]; 
     NrUtil nr=new NrUtil(name,room); 
     nrUtilList.add(nr); 
} 

六.在JSP页面显示 
利用<s:iterator>显示 

这是我在网上找到的一篇，感觉不错，摘了下来。

以下是我在项目中所写：

/* +++++++++++查找新闻，用根据新闻所属系部查找已经通过验证的新闻++++++++++++++ */

@SuppressWarnings("unchecked")

public List<News> findNewsBydepartId(BigDecimal departId, int currentPage,

int lineSize) {

// TODO Auto-generated method stub

System.out.println("************test************"+departId);

String hql = "FROM News AS n WHERE n.department.departId = ? AND n.newsIsvalidate = 1 order by n.newsId desc";

Query q = this.getSession().createQuery(hql);

q.setBigDecimal(0, departId);

q.setFirstResult((currentPage - 1) * lineSize);

q.setMaxResults(lineSize);

List list = q.list();

return list;

}

/* ++++++++++++++++++得到查询的系部新闻的总数++++++++++++++++++++++++++ */

@SuppressWarnings("unchecked")

public int getBydepartIdCount(BigDecimal departId) {

System.out.println("************testcount************"+departId);

session = this.getSession();

Number num = null;

String hql = "SELECT COUNT(*) from News AS n WHERE n.newsIsvalidate = 1 AND n.department.departId = ? ";

Query q = this.session.createQuery(hql);

q.setBigDecimal(0, departId);

List all = q.list();

if (all.size() > 0) {

num = (Number) all.get(0);

System.out.println("查询的系部新闻的总数" + num);

}

return num.intValue();

}