一、業務場景：當客戶下單在指定的時間內如果沒有付款，那我們需要將這筆訂單取消掉，比如好的處理方法是運用延時取消，很多人首先想到的當然是crontab，這個也行，不過這里我們運用swoole的異步毫秒定時器來實現，同樣也不會影響到當前程序的運行。

二、說明，order_status為1時代表客戶下單確定，為2時代表客戶已付款，為0時代表訂單已取消(正是swoole來做的)

三、舉例說明，庫存表csdn_product_stock產品ID為1的產品庫存數量為20，產品ID為2的庫存數量為40，然后客戶下單一筆產品ID1減10，產品ID2減20，所以庫存表只夠2次下單，例子中10秒后自動還原庫存。

如下圖，圖解：

1、第一次下完單產品ID1庫存從20減到了10，產品ID2庫存從40減到了20；2、第二次下完單產品ID的庫存為0了，產品ID2的庫存也為0了，

3、第三次下單時，程序提示Out of stock；

4、過了10秒鐘(每個訂單下單后往后推10秒)，客戶兩次下單，由于沒有付款(csdn_order表的order_status為1)，產品1和產品2的庫存被還原了(csdn_order表的order_status變為0)，客戶又可以繼續下單了

1、所需要sql數據庫表

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');

下面貼出來純手工PHP，很多同學用了原生PHP，就不會運用到框架里去，其實都一樣的，不要想得那么復雜就是了。只要一點就是你用多了，你就會這樣覺得咯。

配置文件config.php ，這個在框架的話，基本上都是配置好了。

<?php $dbHost = "192.168.23.110"; $dbUser = "root"; $dbPassword = "123456"; $dbName = "test"; ?>

swoole都是用在linux系統里的，這里的host你可以自己搭建虛擬主機，也可以網上購買屬于自己的服務器

訂單提交的文件order_submit.php，這里對訂單生成，同時扣除庫存的一系列操作

<?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();//開啟事務處理         $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 = $stmtProductStock->rowCount();             //庫存沒有正常扣除，失敗，庫存表里的product_stock_number設置了為非負數             //如果庫存不足時，sql異常：SQLSTATE[22003]: Numeric value out of range: 1690 BIGINT UNSIGNED value is out of range in '(`test`.`csdn_product_stock`.`product_stock_number` - 20)'             if($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();//提交事務         //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(); } ?>

訂單的延時處理order_cancel.php

<?php require("config.php"); $queryString = getopt('a:'); $userParams = array($queryString); appendLog(date("Y-m-d H:i:s") . "t" . $queryString['a'] . "t" . "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();//開啟事務處理             $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"代表已下單，但未付款，我們還原庫存只針對未付款的訂單             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();//提交事務         }catch(PDOException $e){             echo $e->getMessage();             $pdo->rollback();         }         $pdo = null;         appendLog(date("Y-m-d H:i:s") . "t" . $queryString['a'] . "t" . "endt" . json_encode($queryString));     }, $pdo); } catch (PDOException $e) {     echo $e->getMessage(); } function appendLog($str) {     $dir = 'log.txt';     $fh = fopen($dir, "a");     fwrite($fh, $str . "n");     fclose($fh); } ?>