使用redis队列,因为pop操作是原子的,即使有很多用户同时到达,也是依次执行,推荐使用(mysql事务在高并发下性能下降很厉害,文件锁的方式也是)
先将商品库存如队列
- <?php
- $store=1000;
- $redis=new Redis();
- $result=$redis->connect('127.0.0.1',6379);
- $res=$redis->llen('goods_store');
- echo $res;
- $count=$store-$res;
- for($i=0;$i<$count;$i++){
- $redis->lpush('goods_store',1);
- }
- echo $redis->llen('goods_store');
- ?>
抢购、描述逻辑
- <?php
- $conn=mysql_connect("localhost","big","123456");
- if(!$conn){
- echo "connect failed";
- exit;
- }
- mysql_select_db("big",$conn);
- mysql_query("set names utf8");
- $price=10;
- $user_id=1;
- $goods_id=1;
- $sku_id=11;
- $number=1;
- //生成唯一订单号
- function build_order_no(){
- return date('ymd').substr(implode(NULL, array_map('ord', str_split(substr(uniqid(), 7, 13), 1))), 0, 8);
- }
- //记录日志
- function insertLog($event,$type=0){
- global $conn;
- $sql="insert into ih_log(event,type)
- values('$event','$type')";
- mysql_query($sql,$conn);
- }
- //模拟下单操作
- //下单前判断redis队列库存量
- $redis=new Redis();
- $result=$redis->connect('127.0.0.1',6379);
- $count=$redis->lpop('goods_store');
- if(!$count){
- insertLog('error:no store redis');
- return;
- }
- //生成订单
- $order_sn=build_order_no();
- $sql="insert into ih_order(order_sn,user_id,goods_id,sku_id,price)
- values('$order_sn','$user_id','$goods_id','$sku_id','$price')";
- $order_rs=mysql_query($sql,$conn);
- //库存减少
- $sql="update ih_store set number=number-{$number} where sku_id='$sku_id'";
- $store_rs=mysql_query($sql,$conn);
- if(mysql_affected_rows()){
- insertLog('库存减少成功');
- }else{
- insertLog('库存减少失败');
- }
- --
- -- 数据库: `big`
- --
- -- --------------------------------------------------------
- --
- -- 表的结构 `ih_goods`
- --
- CREATE TABLE IF NOT EXISTS `ih_goods` (
- `goods_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
- `cat_id` int(11) NOT NULL,
- `goods_name` varchar(255) NOT NULL,
- PRIMARY KEY (`goods_id`)
- ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=2 ;
- --
- -- 转存表中的数据 `ih_goods`
- --
- INSERT INTO `ih_goods` (`goods_id`, `cat_id`, `goods_name`) VALUES
- (1, 0, '小米手机');
- -- --------------------------------------------------------
- --
- -- 表的结构 `ih_log`
- --
- CREATE TABLE IF NOT EXISTS `ih_log` (
- `id` int(11) NOT NULL AUTO_INCREMENT,
- `event` varchar(255) NOT NULL,
- `type` tinyint(4) NOT NULL DEFAULT '0',
- `addtime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
- PRIMARY KEY (`id`)
- ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;
- --
- -- 转存表中的数据 `ih_log`
- --
- -- --------------------------------------------------------
- --
- -- 表的结构 `ih_order`
- --
- CREATE TABLE IF NOT EXISTS `ih_order` (
- `id` int(11) NOT NULL AUTO_INCREMENT,
- `order_sn` char(32) NOT NULL,
- `user_id` int(11) NOT NULL,
- `status` int(11) NOT NULL DEFAULT '0',
- `goods_id` int(11) NOT NULL DEFAULT '0',
- `sku_id` int(11) NOT NULL DEFAULT '0',
- `price` float NOT NULL,
- `addtime` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
- PRIMARY KEY (`id`)
- ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='订单表' AUTO_INCREMENT=1 ;
- --
- -- 转存表中的数据 `ih_order`
- --
- -- --------------------------------------------------------
- --
- -- 表的结构 `ih_store`
- --
- CREATE TABLE IF NOT EXISTS `ih_store` (
- `id` int(11) NOT NULL AUTO_INCREMENT,
- `goods_id` int(11) NOT NULL,
- `sku_id` int(10) unsigned NOT NULL DEFAULT '0',
- `number` int(10) NOT NULL DEFAULT '0',
- `freez` int(11) NOT NULL DEFAULT '0' COMMENT '虚拟库存',
- PRIMARY KEY (`id`)
- ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='库存' AUTO_INCREMENT=2 ;
- --
- -- 转存表中的数据 `ih_store`
- --
- INSERT INTO `ih_store` (`id`, `goods_id`, `sku_id`, `number`, `freez`) VALUES
- (1, 1, 11, 500, 0);