'Hack' to work around Doctrine issues with mysql >= 5.7 and queries involving DISTINCT and ORDER BY clauses

services.yml

services:
    Doctrine.SetSQLMode:
        class: AppBundle\Listeners\SetSqlModeListener
        tags:
          - { name: doctrine.event_listener, event: postConnect }

SetSqlModeListener.php

<?php

namespace AppBundle\Listeners;

use Doctrine\DBAL\Event\ConnectionEventArgs;
use Doctrine\DBAL\Events;

/**
 * Work-around for issues with Doctrine & order by clauses in SELECT DISTINCT queries.
 *
 * @TODO: This should be removed when doctrine is updated, see the issue below!
 *
 * https://github.com/doctrine/doctrine2/issues/5622
 */
class SetSqlModeListener
{
    /**
     * @param \Doctrine\DBAL\Event\ConnectionEventArgs $args
     *
     * @return void
     */
    public function postConnect(ConnectionEventArgs $args)
    {
        // Loosy-goosey SQL mode; we'll depend on Doctrine to ensure correctness
        $args->getConnection()->executeUpdate('SET sql_mode="TRADITIONAL,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE"');
    }

    /**
     * {@inheritdoc}
     */
    public function getSubscribedEvents()
    {
        return [Events::postConnect];
    }
}