ThinkPHP实现二级循环读取的方法

$Category = D('Category')->where('category_pid=0')->findAll();

//dump($Category);  

if(!empty($Category)){ //判断一级是否为空

foreach($Category as $key=>$value){   //循环读取

$pid =  $value['category_id'];//字段赋值

$Category[$key]['child'] = D('Category')->where("category_pid =$pid")->select();

//echo D('Category')->getLastSql(); //打印sql语句的写法

}

}

//dump($Category);

$this->assign('Category',$Category);//映射值