Transactions in Symfony 2 and Doctrine 2

transaction.php

<?php

// Code sample to use Transactions

// Get the Entity Manager
$em = $this->getDoctrine()->getEntityManager();

// Suspend the auto-commit
$em->getConnection()->beginTransaction();

try {
    // Get the entity
    $entity = $this->getDoctrine()->getRepository('YourBundle:EntityName')->find($id);
    
    // Code changing the entity properties...
    
    // Save the Entity
    $em->persist($entity);
    $em->flush();
    
    // Commit the transaction
    $em->getConnection()->commit();
} catch (Exception $e) {
    // Rollback on error
    $em->getConnection()->rollback();
    throw $e;
}