PHP 获取所有下级ID

/**
     * 获取所有下级ID
     * @ApiInternal
     */
    public function getAllNextId($id, $data = [])
    {
        $pids = $this->getCol('kcity', ['pid' => $id, 'deletetime' => null], 'id', true);
        if (!empty($pids)) {
            foreach ($pids as $v) {
                $data[] = $v;
                $data = $this->getAllNextId($v, $data);
            }
        }
        if (count($data) > 0) {
            return $data;
        } else {
            return [];
        }
    }