PHP 将父目录下所有子目录查询出来形成一维数组 无限极

有业务需求

需要将某父目录下所有子目录查询出来。形成一个一维数组

比如已知pid=J5

上代码：

$pid = "J5";
$this->find($pid);
foreach($this->data as $key=>$v){
    $res[$key]['id']=$v->id;
    $res[$key]['pId']=$v->pId;
    $res[$key]['name']=$v->name;
}
print_r("<pre>");
var_dump($res);die;

protected $data = [];//设置全局的

public function find ($pid) {
    $temp = [];
    $a=model('work/Comskydrive')->where("pId", $pid)->select();
    if (count($a) > 0) {
        foreach ($a as $key => $value) {
            $temp[]=$value;
            $this->find($value->id);
        }
    }
    $this->data = array_merge($temp,$this->data);
}