php如何生成唯一数字订单号

function generateOrderNumber() {
    // 获取当前时间戳
    $timestamp = time();
   
    // 生成一个随机数
    $random = mt_rand(1000, 9999);
   
    // 组合成订单号
    $orderNumber = $timestamp . $random;
   
    return $orderNumber;
}

// 示例
$orderNumber = generateOrderNumber();
echo $orderNumber;

function generateOrderNumber() {
    // 生成 UUID
    $uuid = uniqid();
   
    // 将 UUID 转换为数字
    $orderNumber = hexdec(str_replace('-', '', $uuid));
   
    return $orderNumber;
}

// 示例
$orderNumber = generateOrderNumber();
echo $orderNumber;

// 假设你使用 MySQL 数据库
$pdo = new PDO('mysql:host=localhost;dbname=your_database', 'username', 'password');

// 插入订单记录
$stmt = $pdo->prepare("INSERT INTO orders (order_number) VALUES (NULL)");
$stmt->execute();

// 获取自增的订单号
$orderNumber = $pdo->lastInsertId();

echo $orderNumber;

$redis = new Redis();
$redis->connect('127.0.0.1', 6379);

// 使用 INCR 命令生成唯一的数字订单号
$orderNumber = $redis->incr('order_number_counter');

echo $orderNumber;

class Snowflake {
    private $epoch = 1577836800000; // 自定义起始时间戳 (2020-01-01)
    private $workerIdBits = 5;
    private $datacenterIdBits = 5;
    private $sequenceBits = 12;
    private $maxWorkerId = -1 ^ (-1 << $this->workerIdBits);
    private $maxDatacenterId = -1 ^ (-1 << $this->datacenterIdBits);
    private $workerIdShift = $this->sequenceBits;
    private $datacenterIdShift = $this->sequenceBits + $this->workerIdBits;
    private $timestampLeftShift = $this->sequenceBits + $this->workerIdBits + $this->datacenterIdBits;
    private $sequenceMask = -1 ^ (-1 << $this->sequenceBits);
    private $workerId;
    private $datacenterId;
    private $sequence = 0;
    private $lastTimestamp = -1;

    public function __construct($workerId, $datacenterId) {
        if ($workerId > $this->maxWorkerId || $workerId < 0) {
            throw new Exception("worker Id can't be greater than " . $this->maxWorkerId . " or less than 0");
        }
        if ($datacenterId > $this->maxDatacenterId || $datacenterId < 0) {
            throw new Exception("datacenter Id can't be greater than " . $this->maxDatacenterId . " or less than 0");
        }
        $this->workerId = $workerId;
        $this->datacenterId = $datacenterId;
    }

    public function nextId() {
        $timestamp = $this->timeGen();
        if ($timestamp == $this->lastTimestamp) {
            $this->sequence = ($this->sequence + 1) & $this->sequenceMask;
            if ($this->sequence == 0) {
                $timestamp = $this->tilNextMillis($this->lastTimestamp);
            }
        } else {
            $this->sequence = 0;
        }

        if ($timestamp < $this->lastTimestamp) {
            throw new Exception("Clock moved backwards. Refusing to generate id for " . ($this->lastTimestamp - $timestamp) . " milliseconds");
        }

        $this->lastTimestamp = $timestamp;

        $id = (($timestamp - $this->epoch) << $this->timestampLeftShift) |
              ($this->datacenterId << $this->datacenterIdShift) |
              ($this->workerId << $this->workerIdShift) |
              $this->sequence;

        return $id;
    }

    protected function tilNextMillis($lastTimestamp) {
        $timestamp = $this->timeGen();
        while ($timestamp <= $lastTimestamp) {
            $timestamp = $this->timeGen();
        }
        return $timestamp;
    }

    protected function timeGen() {
        return floor(microtime(true) * 1000);
    }
}

// 示例
$snowflake = new Snowflake(1, 1);
$orderNumber = $snowflake->nextId();
echo $orderNumber;