php生成订单号

$str=date('Ymd').str_pad(mt_rand(1,99999),5,'0',STR_PAD_LEFT);

第二种

public function GetRandStr($length){
        $str = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
        $len = strlen($str)-1;
        $randstr = date('Ymd');
        for ($i=0;$i<$length;$i++) {
            $num=mt_rand(0,$len);
            $randstr .= $str[$num];
        }
        $res = $this->OrderRepository->getOne(['order_numbers'=>$randstr]);
        if($res){
            $this->GetRandStr(16);
        }
        return $randstr;
    }