Laravel update某一字段值为另一字段值

/**
     * 批量初审
     * @return \Illuminate\Contracts\View\Factory|\Illuminate\View\View
     */
    public function borrowPiShen()
    {
        $record_id = Input::get('record_id');
        if (empty($record_id)) {
            return BaseController::returnJson(405, '请选择数据', null);
        }

        $record_id_arr = explode(',', $record_id);
        $num = YunUserBorrow::whereIn('id', $record_id_arr)
            ->where('status', 0)
            ->update(
                [
                    'status' => 1,
                    'allow_no' => DB::raw('borrow_no'),
                    'name_zc' => AdminUser::getUserData()->name
                ]);

        return BaseController::returnJson(200, "审核了{$num}条记录", null);
    }