thinkphp 关联查询问题

thinkphp 关联查询 有两个表，一个是医院r_hospital,另一个是科室r_department。怎样关联查询，选择完医院之后，科室只显示该医院的科室，而不显示其他医院的了

回复讨论(解决方案)

请贴出你的代码

请贴出你的代码
class RoomAction extends Action{
public function room(){
$room = M('department');
$h_id = I('get.h_id');
$h_name = I('get.h_name');
print_r($h_id);
print_r($h_name);
$data =$_POST['text'];
print_r($data);
if($data !=''){
//执行sql语句（执行like查询，搜索）
$map['name'] = array('like',"%$data%");
$list = $room->where($map)->select();
$this->list = $list;
$this->display();
}else{
$map['hospital_id'] = $h_id;
$list = $room->where($map)->select();
$this->assign("list", $list)；
$this->display();
}
}

THINKPHP 中关联查询（多表查询）可以使用 table() 方法或和join方法，请看示例：1、table()$list = $user->table('user_status stats, user_profile profile')->where('stats.id = profile.typeid')->field('stats.id as id, stats.display as display, profile.title as title,profile.content as content')->order('stats.id desc' )->select();2、join()$user = new Model('user');$list = $user->join('RIGHT JOIN user_profile ON user_stats.id = user_profile.typeid' );3、原生查询$Model = new Model();$sql = 'select a.id,a.title,b.content  from think_test1 as a, think_test2 as b where a.id=b.id '.$map.' order by a.id  '.$sort.' limit '.$p->firstRow.','.$p->listRows;$voList = $Model->query($sql);