thinkphp6でmysqlの悲観的ロックを使って商品の売れ残り問題を解決するための実装

CREATE TABLE `goods` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(100) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
  `status` tinyint(1) NOT NULL DEFAULT '1',
  `total` int(11) NOT NULL DEFAULT '0',
  `sell` int(11) NOT NULL DEFAULT '100',
  `price` decimal(10,2) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 
INSERT INTO `test`. `goods`(`id`, `name`, `status`, `total`, `sell`, `price`) VALUES (1, 'goods', 1, 0, 100, 15.00);

CREATE TABLE `orders` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `uid` int(11) NOT NULL DEFAULT '0',
  `create_time` datetime NOT NULL,
  `status` tinyint(1) NOT NULL DEFAULT '1',
  `goods_id` int(11) NOT NULL DEFAULT '0',
  `order_no` varchar(200) COLLATE utf8_unicode_ci NOT NULL DEFAULT '',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

<?php
 
namespace app\controller;
 
use app\BaseController;
use think\facade\Db;
 
class Test extends BaseController
{
 
    /**
     * without locking
     * @return string|void
     */
    public function test_1()
    {
        $num = 1;
        $goods_id = 1;
        Db::startTrans();
        try {
            $where = [];
            $where['id'] = $goods_id;
            $where['status'] = 1;
            $goods_info = Db::table('goods')->where($where)->find();
            if (empty($goods_info)) {
                return 'Item does not exist';
            }
            $total = $goods_info['total'];
            $sell = $goods_info['sell'];
            if ($total < $num) {
                return 'Out of stock';
            }
            $data['total'] = $total-$num;
            $data['sell'] = $sell+$num;
            $res = Db::table('goods')->where(['id'=>$goods_id])->update($data);
            $order_data = [];
            $order_data['uid'] = rand(1000,9999);
            $order_data['status'] = 1;
            $order_data['create_time'] = date('Y-m-d H:i:s');
            $order_data['goods_id'] = $goods_id;
            $order_data['order_no'] = date('YmdHis').rand(1000,10000);
            $order_res = Db::table('orders')->insert($order_data);
            Db::commit();
        } catch (\Exception $e) {
            // Roll back the transaction
            Db::rollback();
            echo $e->getMessage();
            exit('rollback');
        }
        echo 'Request successful';
    }
 
    /**
     * locking - pessimistic locking
     * @return string|void
     */
    public function test_2()
    {
        $num = 1;
        $goods_id = 1;
        Db::startTrans();
        try {
            $where = [];
            $where['id'] = $goods_id;
            $where['status'] = 1;
            $goods_info = Db::table('goods')->lock(true)->where($where)->find();
            if (empty($goods_info)) {
                return 'Item does not exist';
            }
            $total = $goods_info['total'];
            $sell = $goods_info['sell'];
            if ($total < $num) {
                return 'Out of stock';
            }
            $data['total'] = $total-$num;
            $data['sell'] = $sell+$num;
            $res = Db::table('goods')->where(['id'=>$goods_id])->update($data);
            $order_data = [];
            $order_data['uid'] = rand(1000,9999);
            $order_data['status'] = 1;
            $order_data['goods_id'] = $goods_id;
            $order_data['order_no'] = date('YmdHis').rand(1000,10000);
            $order_data['create_time'] = date('Y-m-d H:i:s');
            $order_res = Db::table('orders')->insert($order_data);
            Db::commit();
        } catch (\Exception $e) {
            // Roll back the transaction
            Db::rollback();
            echo $e->getMessage();
            exit('rollback');
 
        }
        echo 'Request successful';
    }
 
}