pdo + 事务处理 处理线性事务

/*
        *   事物处理线性操作。
        *    以转账为例
        */
        header('Content-type:text/html;charset=utf-8');

        $opt = array(PDO::ATTR_PERSISTENT => TRUE);
        $dsn = "mysql:dbname=0328;host=127.0.0.1";
        $user = "root";
        $password = '';

        $dbh = new PDO($dsn,$user,$password,$opt);
        $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT,0); //关闭自动提交
        try{
            $dbh->beginTransaction();
            $price = 10;
            $is_acheived = $dbh->exec("update account set money=money-$price where name='王贺军'");
            if($is_acheived > 0){
                echo '王贺军成功转出 ' . $price . '元<br>';
            }else{
                throw new PDOException("转出失败！<br>");
            }
            $is_acheived = $dbh->exec("update account set money=money+$price where name='王二'");
            if($is_acheived > 0){
                echo '王二成功转入 ' . $price . '元<br>';
            }else{
                throw new PDOException("转入失败！<br>");
            }
            echo '交易成功！';
            $dbh->commit();
        }catch(PDOException $e){
            echo "交易失败 " . $e->getMessage();
            $dbh->rollback();
        }
        $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT,1); //开启自动提交