业务场景
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：
正文讲解
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") . "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();//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") . "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);
}
?>
