PDO::rollBack

(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo >= 0.1.0)

PDO::rollBack — 回滚一个事务

说明

PDO::rollBack(): bool

回滚由 PDO::beginTransaction() 发起的当前事务。如果没有事务激活，将抛出一个 PDOException 异常。

如果数据库被设置成自动提交模式，此函数（方法）在回滚事务之后将恢复自动提交模式。

包括 MySQL 在内的一些数据库，当在一个事务内有类似删除或创建数据表等 DLL 语句时，会自动导致一个隐式地提交。隐式地提交将无法回滚此事务范围内的任何更改。

返回值

成功时返回 true，或者在失败时返回 false。

范例

示例 #1 回滚一个事务

下面例子在回滚更改之前开始一个事务并发出两条修改数据库的语句。但在 MySQL 中，DROP TABLE 语句自动提交事务，因此在此事务内的任何更改都不会被回滚。


<?php
/* 开始一个事务，关闭自动提交 */
$dbh->beginTransaction();

/* 更改数据库架构和数据  */
$sth = $dbh->exec("DROP TABLE fruit");
$sth = $dbh->exec("UPDATE dessert
    SET name = 'hamburger'");

/*  识别错误且回滚更改  */
$dbh->rollBack();

/*  此时数据库连接恢复到自动提交模式  */
?>

参见

PDO::beginTransaction() - 启动一个事务
PDO::commit() - 提交一个事务
事务和自动提交

add a note

User Contributed Notes 4 notes

down

JonasJ ¶

14 years ago


Just a quick (and perhaps obvious) note for MySQL users;

Don't scratch your head if it isn't working if you are using a MyISAM table to test the rollbacks with. 

Both rollBack() and beginTransaction() will return TRUE but the rollBack will not happen.

Convert the table to InnoDB and run the test again.

down

brian at diamondsea dot com ¶

14 years ago


Here is a way of testing that your transaction has started when using MySQL's InnoDB tables.  It will fail if you are using MySQL's MyISAM tables, which do not support transactions but will also not return an error when using them.

<?
// Begin the transaction
$dbh->beginTransaction();

// To verify that a transaction has started, try to create an (illegal for InnoDB) nested transaction.
//    If it works, the first transaction did not start correctly or is unsupported (such as on MyISAM tables)
try {
    $dbh->beginTransaction();
    die('Cancelling, Transaction was not properly started');
} catch (PDOException $e) {
    print "Transaction is running (because trying another one failed)\n";
}
?>

down

Petros Giakouvakis ¶

11 years ago


Should anyone reading this be slightly panicked because they just discovered that their MySQL  tables are MyIsam and not InnoDb, don't worry... You can very easily change the storage engine using the following query: 

ALTER TABLE your_table_name ENGINE = innodb;

down

-4

linfo2003 at libero dot it ¶

15 years ago


Since "It is an error to call this method if no transaction is active", it could be useful (even if not indispensable) to have a method which returns true if a transaction is active.

try {
    $dbh->beginTransaction();
    ...
} catch (PDOException $e) {
    if ($dbh->isTransactionActive())  // this function does NOT exist
        $dbh->rollBack();
    ...
}

In the meanwhile, I'm using this code:

    ...
} catch (PDOException $e) {
    try { $dbh->rollBack(); } catch (Exception $e2) {}
    ...
}

It's not so chic, but it works fine.

add a note

官方地址：https://www.php.net/manual/en/pdo.rollback.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络数据库 JAVA 面试 NoSQL C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 adodb手册 ADORecordSet对象 opcache预加载 Composer的Packagist资源 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet mysql面试题 PHP json解析（json_decode）页面工具 php中几种注释规范 [原创]诡异的php-fpm超时问题纯php实现DES以及TripleDES加密算法 php 修改图片大小支持php7的性能采集扩展 PHP5 扩展SOAP 调用 webservice

略微加速

PHP官方手册 - 互联网笔记

PDO::rollBack

说明

返回值

范例

参见

User Contributed Notes 4 notes