mysql事务处理

<?php 
$dsn=‘mysql:host=localhost;dbname=mssc‘;
$user=‘root‘;
$password=‘‘;
$orderno=‘111‘;
$orderno1=‘222‘;
try {
    $dbh=new PDO($dsn,$user,$password);
    $dbh->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION); 
    $dbh->beginTransaction();
    $sql="INSERT INTO onethink_order(order_no) VALUES(:orderno)";
    $stmt=$dbh->prepare($sql);
    $stmt->bindParam(‘:orderno‘,$orderno);
    $stmt->execute();
    $sql="INSERT INTO onethink_order(order_no) VALUES(:orderno1)";
    $stmt=$dbh->prepare($sql);
    $stmt->bindParam(‘:orderno1‘,$orderno1);
    $stmt->execute();
    $dbh->commit();
} catch (PDOException $e) {
    $dbh->rollBack();
    echo ‘SQL Query:‘.$sql.‘</br>‘;
    echo ‘Connection failed:‘.$e->getMessage();
}
 ?>