/**
	  * 迭代获取下级
	  */
	 public function getChild($ids = array(),$pids = array()){
	 	$sql = "select catId from __PREFIX__product_cats where catFlag=1 and parentId in(".implode(',',$pids).")";
	 	$rs = $this->query($sql);
	 	if(count($rs)>0){
	 		$cids = array();
		 	foreach ($rs as $key =>$v){
		 		$cids[] = $v['catId'];
		 	}
		 	$ids = array_merge($ids,$cids);
		 	return $this->getChild($ids,$cids);
		 	
	 	}else{
	 		return $ids;
	 	}
	 }

使用：

//获取子集
	 	$ids = array();
		$ids[] = (int)I('id');
	 	$ids = $this->getChild($ids,$ids);
		
		//删除属于分类的信息
		if(!empty($ids)){
			$sql = "delete from __PREFIX__products where catId in (".implode(",",$ids).")";
			$this->execute($sql);
		}