面试官：说说swoole+PHP实现自动取消订单，还原库存等操作

一、业务场景

当客户下单在指定的时间内如果没有付款，那我们需要将这笔订单取消掉，比如好的处理方法是运用延时取消，这里我们用到了swoole，运用swoole的异步毫秒定时器不会影响到当前程序的运行，具体参考：https://wiki.swoole.com/wiki/page/319.html

二、说明

order_status为1时代表客户下单确定，为2时代表客户已付款，为0时代表订单已取消(正是swoole来做的)，下面的代表我没有用框架，比较纯的PHP代表方便理解和应用

三、举例说明

库存表csdn_product_stock产品ID为1的产品库存数量为20，产品ID为2的库存数量为40，然后客户下单一笔产品ID1减10，产品ID2减20，所以库存表只够2次下单，例子中10秒后自动还原库存，如下图：

图解：1、第一次下完单产品ID1库存从20减到了10，产品ID2库存从40减到了20；2、第二次下完单产品ID的库存为0了，产品ID2的库存也为0了，3、第三次下单时，程序提示Out of stock；4、过了10秒钟(每个订单下单后往后推10秒)，客户两次下单，由于没有付款(csdn_order表的order_status为1)，产品1和产品2的库存被还原了(csdn_order表的order_status变为0)，客户又可以继续下单了

1、所需要sql数据库表

DROP TABLE IF EXISTS `csdn_order`;
CREATE TABLE `csdn_order` (
  `order_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `order_amount` float(10,2) unsigned NOT NULL DEFAULT '0.00',
  `user_name` varchar(64) CHARACTER SET latin1 NOT NULL DEFAULT '',
  `order_status` tinyint(2) unsigned NOT NULL DEFAULT '0',
  `date_created` datetime NOT NULL,
  PRIMARY KEY (`order_id`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `csdn_order_detail`;
CREATE TABLE `csdn_order_detail` (
  `detail_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `order_id` int(10) unsigned NOT NULL,
  `product_id` int(10) NOT NULL,
  `product_price` float(10,2) NOT NULL,
  `product_number` smallint(4) unsigned NOT NULL DEFAULT '0',
  `date_created` datetime NOT NULL,
  PRIMARY KEY (`detail_id`),
  KEY `idx_order_id` (`order_id`)
) ENGINE=InnoDB AUTO_INCREMENT=0 DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `csdn_product_stock`;
CREATE TABLE `csdn_product_stock` (
  `auto_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `product_id` int(10) NOT NULL,
  `product_stock_number` int(10) unsigned NOT NULL,
  `date_modified` datetime NOT NULL,
  PRIMARY KEY (`auto_id`),
  KEY `idx_product_id` (`product_id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

INSERT INTO `csdn_product_stock` VALUES ('1', '1', '20', '2018-09-13 19:36:19');
INSERT INTO `csdn_product_stock` VALUES ('2', '2', '40', '2018-09-13 19:36:19');

2、数据库配置信息：config.php

<?php
$dbHost = "192.168.0.110";
$dbUser = "root";
$dbPassword = "123456";
$dbName = "test123";
?>

3、order_submit.php，生成订单

<?php
require("config.php");
try {
    $pdo = new PDO("mysql:host=" . $dbHost . ";dbname=" . $dbName, $dbUser, $dbPassword, array(PDO::ATTR_PERSISTENT => true));
    $pdo->setAttribute(PDO::ATTR_AUTOCOMMIT, 1);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    $orderInfo = array(
        'order_amount' => 10.92,
        'user_name' => 'yusan',
        'order_status' => 1,
        'date_created' => 'now()',
        'product_lit' => array(
            0 => array(
                'product_id' => 1,
                'product_price' => 5.00,
                'product_number' => 10,
                'date_created' => 'now()'
            ),
            1 => array(
                'product_id' => 2,
                'product_price' => 5.92,
                'product_number' => 20,
                'date_created' => 'now()'
            )
        )
    );

    try{
        $pdo->beginTransaction();//开启事务处理

        $sql = 'insert into csdn_order (order_amount, user_name, order_status, date_created) values (:orderAmount, :userName, :orderStatus, now())';
        $stmt = $pdo->prepare($sql);  
        $affectedRows = $stmt->execute(array(':orderAmount' => $orderInfo['order_amount'], ':userName' => $orderInfo['user_name'], ':orderStatus' => $orderInfo['order_status']));
        $orderId = $pdo->lastInsertId();
        if(!$affectedRows) {
            throw new PDOException("Failure to submit order!");
        }
        foreach($orderInfo['product_lit'] as $productInfo) {

            $sqlProductDetail = 'insert into csdn_order_detail (order_id, product_id, product_price, product_number, date_created) values (:orderId, :productId, :productPrice, :productNumber, now())';
            $stmtProductDetail = $pdo->prepare($sqlProductDetail);  
            $stmtProductDetail->execute(array(':orderId' => $orderId, ':productId' =>  $productInfo['product_id'], ':productPrice' => $productInfo['product_price'], ':productNumber' => $productInfo['product_number']));

            $sqlCheck = "select product_stock_number from csdn_product_stock where product_id=:productId";  
            $stmtCheck = $pdo->prepare($sqlCheck);  
            $stmtCheck->execute(array(':productId' => $productInfo['product_id']));  
            $rowCheck = $stmtCheck->fetch(PDO::FETCH_ASSOC);
            if($rowCheck['product_stock_number'] < $productInfo['product_number']) {
                throw new PDOException("Out of stock, Failure to submit order!");
            }


            $sqlProductStock = 'update csdn_product_stock set product_stock_number=product_stock_number-:productNumber, date_modified=now() where product_id=:productId';
            $stmtProductStock = $pdo->prepare($sqlProductStock);  
            $stmtProductStock->execute(array(':productNumber' => $productInfo['product_number'], ':productId' => $productInfo['product_id']));
            $affectedRowsProductStock = $stmtProductStock->rowCount();

            //库存没有正常扣除，失败，库存表里的product_stock_number设置了为非负数
            //如果库存不足时，sql异常：SQLSTATE[22003]: Numeric value out of range: 1690 BIGINT UNSIGNED value is out of range in '(`test`.`csdn_product_stock`.`product_stock_number` - 20)'
            if($affectedRowsProductStock <= 0) {
                throw new PDOException("Out of stock, Failure to submit order!");
            }
        }
        echo "Successful, Order Id is：" . $orderId ."，Order Amount is：" . $orderInfo['order_amount'] . "。";
        $pdo->commit();//提交事务
        //exec("php order_cancel.php -a" . $orderId . " &");
        pclose(popen('php order_cancel.php -a ' . $orderId . ' &', 'w'));
        //system("php order_cancel.php -a" . $orderId . " &", $phpResult);
        //echo $phpResult;
    }catch(PDOException $e){
        echo $e->getMessage();
        $pdo->rollback();
    }
    $pdo = null;
} catch (PDOException $e) {
    echo $e->getMessage();
}
?>

4、order_cancel.php，这个方法主要就是做订单自动取消，并还原库存的业务处理

<?php
require("config.php");
$queryString = getopt('a:');
$userParams = array($queryString);
appendLog(date("Y-m-d H:i:s") . "	" . $queryString['a'] . "	" . "start");

try {
    $pdo = new PDO("mysql:host=" . $dbHost . ";dbname=" . $dbName, $dbUser, $dbPassword, array(PDO::ATTR_PERSISTENT => true));
    $pdo->setAttribute(PDO::ATTR_AUTOCOMMIT, 0);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    swoole_timer_after(10000, function ($queryString) {
        global $queryString, $pdo;

        try{
            $pdo->beginTransaction();//开启事务处理

            $orderId = $queryString['a'];  
            $sql = "select order_status from csdn_order where order_id=:orderId";  
            $stmt = $pdo->prepare($sql);  
            $stmt->execute(array(':orderId' => $orderId));  
            $row = $stmt->fetch(PDO::FETCH_ASSOC);
            //$row['order_status'] === "1"代表已下单，但未付款，我们还原库存只针对未付款的订单
            if(isset($row['order_status']) && $row['order_status'] === "1") {
                $sqlOrderDetail = "select product_id, product_number from csdn_order_detail where order_id=:orderId";  
                $stmtOrderDetail = $pdo->prepare($sqlOrderDetail);  
                $stmtOrderDetail->execute(array(':orderId' => $orderId));  
                while($rowOrderDetail = $stmtOrderDetail->fetch(PDO::FETCH_ASSOC)) {
                    $sqlRestoreStock = "update csdn_product_stock set product_stock_number=product_stock_number + :productNumber, date_modified=now() where product_id=:productId";  
                    $stmtRestoreStock = $pdo->prepare($sqlRestoreStock);
                    $stmtRestoreStock->execute(array(':productNumber' => $rowOrderDetail['product_number'], ':productId' => $rowOrderDetail['product_id']));
                }

                $sqlRestoreOrder = "update csdn_order set order_status=:orderStatus where order_id=:orderId";  
                $stmtRestoreOrder = $pdo->prepare($sqlRestoreOrder);
                $stmtRestoreOrder->execute(array(':orderStatus' => 0, ':orderId' => $orderId));
            }

            $pdo->commit();//提交事务
        }catch(PDOException $e){
            echo $e->getMessage();
            $pdo->rollback();
        }
        $pdo = null;

        appendLog(date("Y-m-d H:i:s") . "	" . $queryString['a'] . "	" . "end	" . json_encode($queryString));
    }, $pdo);

} catch (PDOException $e) {
    echo $e->getMessage();
}
function appendLog($str) {
    $dir = 'log.txt';
    $fh = fopen($dir, "a");
    fwrite($fh, $str . "
");
    fclose($fh);
}
?>

点关注，不迷路

好了各位，以上就是这篇文章的全部内容了，能看到这里的人呀，都是人才。之前说过，PHP方面的技术点很多，也是因为太多了，实在是写不过来，写过来了大家也不会看的太多，所以我这里把它整理成了PDF和文档，如果有需要的可以

点击进入暗号: PHP+「平台」

---

更多学习内容可以访问【对标大厂】精品PHP架构师教程目录大全，只要你能看完保证薪资上升一个台阶（持续更新）

以上内容希望帮助到大家，很多PHPer在进阶的时候总会遇到一些问题和瓶颈，业务代码写多了没有方向感，不知道该从那里入手去提升，对此我整理了一些资料，包括但不限于：分布式架构、高可扩展、高性能、高并发、服务器性能调优、TP6，laravel，YII2，Redis，Swoole、Swoft、Kafka、Mysql优化、shell脚本、Docker、微服务、Nginx等多个知识点高级进阶干货需要的可以免费分享给大家，需要的可以加入我的 PHP技术交流群