php+mysql 原生事务回滚

<?php
    $conn = mysql_connect('127.0.0.1', 'root', '');
    mysql_select_db('msc_test');
    mysql_query('SET NAMES UTF8');

    # 开启事务
    mysql_query("START TRANSACTION");

    $sql1 = "INSERT INTO `msc_user` VALUES ('1', 'msc', '男', '1991')";
    $sql2 = "UPDATE `msc_account` SET `money` = `money` + 1000*2 WHERE `user` = 'msc'";

    $res1 = mysql_query($sql1);
    $res2 = mysql_query($sql2);

    if ($res1 && $res2){
        // 提交事务
        mysql_query('COMMIT');
        echo "成功";
    }else{
        // 事务回滚
        mysql_query('ROLLBACK');
        echo "失败";
    }