Mysql长连接断开，后续采集连接操作重复

Question

当我获得到pdo的长连接时，执行事务插入操作，我手动断开连接或mysql自动断开连接一段时间，我重新获取连接执行事务将继续执行最后一个操作，导致数据插入到数据库中

mysql5.7

$pdoOptions       = [
    \PDO::ATTR_TIMEOUT    => 30,
    \PDO::ATTR_PERSISTENT => true,
];
$dsn              = "mysql:host=mysql;port=3306;dbname=test;charset=utf8";
$connection = new \PDO($dsn, 'root', 'root', $pdoOptions);
try{
    $connection->beginTransaction();
    $smtm = $connection->prepare("INSERT INTO classic(class_name)VALUES(:name)");
    $smtm->bindValue(':name','111');
    $smtm->execute();
    throw  new \Exception('Manual exception throwing');
    $connection->commit();
}catch (\Throwable $e){
    echo ('Received exception information thrown:' . $e->getMessage());
    echo "\n";
    try{
        $connection->rollBack();
    }catch (\Throwable $e2){
        echo ('Exception fired by rollback：' . $e->getMessage());
        echo "\n";
    }
}

$connection = null;
echo 'connection Set to null, the current pdo link is broken';
echo "\n";
$connection = new \PDO($dsn, 'root', 'root', $pdoOptions);
echo 'Set to null and get the new link again to determine whether it is in the transaction:' .($connection->inTransaction()?'是':'否');
echo "\n";
$connection->beginTransaction();
echo 'BeginTransaction to start a transaction';
echo "\n";
try{
    echo('New link transaction open status:'.($connection->inTransaction()?'yes':'no'));
    echo "\n";
    $smtm = $connection->prepare("INSERT INTO classic(class_name)VALUES(:name)");
    echo ('Current linked transaction status after connection->prepare() execution:'.($connection->inTransaction()?'yes':'no'));
    echo "\n";
    $smtm->bindValue(':name','222');
//    echo $smtm->queryString;
    $smtm->execute();
    echo 'After the new link is obtained, an exception is thrown and the second execution fails to roll it back';
    echo "\n";
    throw  new \Exception('The second transaction executes, throwing an exception manually');
    $connection->commit();
}catch (\Throwable $e){
     echo ('Get new link exception catch:' . $e->getMessage());
    echo "\n";
    try{
        $connection->rollBack();
    }catch (\Throwable $e2){
        echo ('The exception triggered by the second rollback:' . $e2->getMessage());
        echo "\n";
    }
}

表格

CREATE TABLE `classic` (
    `id` INT(11) NOT NULL AUTO_INCREMENT,
    `class_name` VARCHAR(50) NULL DEFAULT NULL,
    PRIMARY KEY (`id`)
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
AUTO_INCREMENT=1;

此代码会使数据库实际插入一段数据

Answer 1

很奇怪，第二个事务是如何找到提交的方法的。将第二个连接名称更改为$connection1并运行。

<?php
namespace app;
ini_set('display_errors', 1);
$pdoOptions       = [
    \PDO::ATTR_TIMEOUT    => 30,
    \PDO::ATTR_PERSISTENT => true,
];
$dsn              = "mysql:host=localhost;port=3306;dbname=test;charset=utf8";
$connection = new \PDO($dsn, 'root', 'infiniti', $pdoOptions);
try{
    $connection->beginTransaction();
    $smtm = $connection->prepare("INSERT INTO classic(class_name)VALUES(:name)");
    $smtm->bindValue(':name','111');
    $smtm->execute();
    throw  new \Exception('Manual exception throwing');
    $connection->commit();
}catch (\Exception $e){
    echo ('Received exception information thrown:' . $e->getMessage());
    echo "\n";
    try{
        $connection->rollBack();
    }catch (\Exception $e2){
        echo ('Exception fired by rollback：' . $e->getMessage());
        echo "\n";
    }
}

$connection = null;
echo 'connection Set to null, the current pdo link is broken';
echo "\n";
$connection1 = new \PDO($dsn, 'root', 'infiniti', $pdoOptions);
echo 'Set to null and get the new link again to determine whether it is in the transaction:' .($connection1->inTransaction()?'yes':'no');
echo "\n";
$connection1->beginTransaction();
echo 'BeginTransaction to start a transaction';
echo "\n";
try{
    echo('New link transaction open status:'.($connection1->inTransaction()?'yes':'no'));
    echo "\n";
    $smtm = $connection1->prepare("INSERT INTO classic(class_name)VALUES(:name)");
    echo ('Current linked transaction status after connection->prepare() execution:'.($connection1->inTransaction()?'yes':'no'));
    echo "\n";
    $smtm->bindValue(':name','222');
//    echo $smtm->queryString;
    $smtm->execute();
    echo 'After the new link is obtained, an exception is thrown and the second execution fails to roll it back';
    echo "\n";
    throw  new \Exception('The second transaction executes, throwing an exception manually');
    echo 'wowowowo'."\n";
    $connection1->commit();

}catch (\Exception $e){
     echo ('Get new link exception catch:' . $e->getMessage());
    echo "\n";
    try{
        $connection1->rollBack();
    }catch (\Exception $e2){
        echo ('The exception triggered by the second rollback:' . $e2->getMessage());
        echo "\n";
    }
}
?>

Answer 2

关闭连接时，应同时关闭connection对象和statement对象

$connection = null；$smtm = null;

我想这应该能解决你的问题。花了更多的时间来修复！

<?php
namespace app;
ini_set('display_errors', 1);
$pdoOptions       = [
    \PDO::ATTR_TIMEOUT    => 30,
    \PDO::ATTR_PERSISTENT => true,
];
$dsn              = "mysql:host=localhost;port=3306;dbname=test;charset=utf8";
$connection = new \PDO($dsn, 'root', 'infiniti', $pdoOptions);
try{
    $connection->beginTransaction();
    $smtm = $connection->prepare("INSERT INTO classic(class_name)VALUES(:name)");
    $smtm->bindValue(':name','111');
    $smtm->execute();
    throw  new \Exception('Manual exception throwing');
    $connection->commit();
}catch (\Exception $e){
    echo ('Received exception information thrown:' . $e->getMessage());
    echo "\n";
    try{
        $connection->rollBack();
    }catch (\Exception $e2){
        echo ('Exception fired by rollback：' . $e->getMessage());
        echo "\n";
    }
}

$connection = null;
$smtm = null;

echo 'connection Set to null, the current pdo link is broken';
echo "\n";
$connection = new \PDO($dsn, 'root', 'infiniti', $pdoOptions);
echo 'Set to null and get the new link again to determine whether it is in the transaction:' .($connection->inTransaction()?'yes':'no');
echo "\n";
$connection->beginTransaction();
echo 'BeginTransaction to start a transaction';
echo "\n";
try{
    echo('New link transaction open status:'.($connection->inTransaction()?'yes':'no'));
    echo "\n";
    $smtm = $connection->prepare("INSERT INTO classic(class_name)VALUES(:name)");
    echo ('Current linked transaction status after connection->prepare() execution:'.($connection->inTransaction()?'yes':'no'));
    echo "\n";
    $smtm->bindValue(':name','222');
//    echo $smtm->queryString;
    $smtm->execute();
    echo 'After the new link is obtained, an exception is thrown and the second execution fails to roll it back';
    echo "\n";
    throw  new \Exception('The second transaction executes, throwing an exception manually');
    echo 'wowowowo'."\n";
    $connection->commit();

}catch (\Exception $e){
     echo ('Get new link exception catch:' . $e->getMessage());
    echo "\n";
    try{
        $connection->rollBack();
    }catch (\Exception $e2){
        echo ('The exception triggered by the second rollback:' . $e2->getMessage());
        echo "\n";
    }
}
?>