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我有一个 PDO 类，我创建了它来帮助我与 MySQL 服务器连接和通信。我正在尝试向类添加一个函数或方法，这将帮助我打开一个到 MySQL 的事务以及提交和回滚。我从未使用过提交和回滚。

我认为会以某种方式在每次调用此类时以某种方式停止自动提交，并在抛出错误时回滚并在每次此类 id 关闭时提交。

我的 2 个问题是：1）打开连接然后运行多个查询提交如果没有错误否则回滚然后关闭连接是个好主意吗？2）我如何设法将其添加到我现有的课程中？这是我当前的 PHP 类

<?php

class connection {

    private $connString;
    private $userName;
    private $passCode;
    private $server;
    private $pdo;
    private $errorMessage;
    private $pdo_opt = array();
    protected $lastQueryTime;
    protected $lastQuery;
    protected $effectedRows;



    function __construct($dbName = DATABASE_NAME, $serverName = DATABASE_HOST){

        //SET PDO options
        if(TESTING_ENVIRONMENT == 1){
            $this->pdo_opt[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
            $this->pdo_opt[PDO::ATTR_DEFAULT_FETCH_MODE]  = PDO::FETCH_ASSOC;
        }

            $this->pdo_opt[PDO::MYSQL_ATTR_INIT_COMMAND] = 'SET NAMES utf8';
            $this->pdo_opt[PDO::SQLSRV_ATTR_ENCODING]  = PDO::SQLSRV_ENCODING_UTF8;

        //sets credentials
        $this->setConnectionCredentials($dbName, $serverName);

        //start the connect
        $this->startConnection();

    }

    function startConnection(){


            $this->pdo = new PDO($this->connString, $this->userName, $this->passCode, $this->pdo_opt);

            if( ! $this->pdo){

                $this->errorMessage  = 'Failed to connect to database. Please try to refresh this page in 1 minute. ';
                $this->errorMessage .= 'However, if you continue to see this message please contact your system administrator.';
                echo $this->getError();
            }
    }


    //this will close the PDO connection
    public function endConnection(){

        $this->pdo = null;
    }

    //return a dataset with the results
    public function getDataSet($query, $data = NULL)
    {
        $start = microtime(true);
        $cmd = $this->pdo->prepare( $query );

        $cmd->execute($data);
        $this->effectedRows = $cmd->rowCount();
        $ret = $cmd->fetchAll();
        //$cmd->closeCursor();
        $this->lastQueryTime = microtime(true) - $start;
        $this->lastQuery = $query;

        return $ret;
    }



    public function processQuery($query, $data = NULL)
    {
        $start = microtime(true);
               //$this->pdo->beginTransaction();


        $cmd = $this->pdo->prepare( $query );
        $ret = $cmd->execute($data);
               //$this->pdo->commit();
               //$cmd->closeCursor();
        $this->effectedRows = $cmd->rowCount();
        $this->lastQueryTime = microtime(true) - $start;
        $this->lastQuery = $query;

        return $ret;
    }


    //return last insert id
    public function lastInsertId($name = NULL) {
        if(!$this->pdo) {
            return false;
        }

        return $this->pdo->lastInsertId($name);
    }


    //return last insert id
    public function rowCount() {

        return $this->effectedRows;
    }


    public function getOneResult($query, $data = NULL){
        $cmd = $this->pdo->prepare( $query );
        $cmd->execute($data);

        return $cmd->fetchColumn();
    }

    public function getError(){
        if($this->errorMessage != '')
            return $this->errorMessage;
        else
            return true;  //no errors found

    }

    //this where you need to set new server credentials with a new case statment
    function setConnectionCredentials($dbName, $serv){

        switch($serv){

            //the defaults are predefined in the APP_configuration file - DO NOT CHANGE THE DEFAULT
            default:
                $this->connString   = 'mysql:host='.DATABASE_HOST.';dbname='.DATABASE_NAME.';charset=utf8';
                $this->userName     = DATABASE_USERNAME;
                $this->passCode     = DATABASE_PASSWORD;
            break;

            }

    }

public function lastQueryTime() {
    if(!$this->lastQueryTime) {
        throw new Exception('no query has been executed yet');
    }
    return $this->lastQueryTime;
}

public function lastQuery() {
    if(!$this->lastQuery) {
        throw new Exception('no query has been executed yet');
    }
    return $this->lastQuery;
}

}

?>

收集通知后编辑是我需要的这种方式吗？

$db = new connection();
$db->beginTransaction(); //begin transaction
$db->processQuery();     //process query #1
$db->processQuery();     //process query #2
$db->commit();           //commit changes
$db->endConnection();    //close connection


public function beginTransaction(){
    $this->pdo->beginTransaction(); 
}

public function commit(){
    $this->pdo->commit(); 
}

public function rollBack(){
    $this->pdo->rollBack(); 
}   

//this will close the PDO connection
public function endConnection(){
    $this->pdo = null;
}
4

1 回答 1

0

PDO::beginTransaction

/* Begin a transaction, turning off autocommit */
$dbh->beginTransaction();

PDO::提交

/* Commit the changes */
$dbh->commit();

在这一点上，感觉你的connection班级水平相当低。我的猜测是它没有足够的信息来自己知道何时开始事务以及何时提交事务。您可能必须提供相应的方法（以及rollback方法），并让您的类的用户在需要时调用它们。

关于您的问题，事务不仅是回滚本地更改。它也与原子性有关。那是要么全部完成要么根本不完成的操作序列。不要忘记将同时访问您的数据库。有时您不希望有人在您操作数据时更改数据。

于 2013-08-01T21:21:00.167 回答