Symfony2 Connections inside controller

connectionController.php

    public function connectDb(\Doctrine\ORM\EntityManagerInterface $em, $dbName, $connectionFactory){
        $centerDb = $em->getRepository('SmCommonBundle:Center')->findOneBy(array('dbName' => $dbName));

        if($centerDb) {
            $server = $this->container->getParameter('database_host');
            $port   = $this->container->getParameter('database_port');
            $result = $connectionFactory->createConnection(array(
                'driver'   => $this->container->getParameter('database_driver'),
                'user'     => $centerDb->getDbUserName(),
                'password' => base64_decode($centerDb->getDbUserPass()),
                'host'     => $server,
                'port'     => $port,
                'dbname'   => $dbName,
            ));
            // Versión Servidor Windows
            // $result = new PDO("dblib:host=qa;dbname=$dbName",$centerDb->getDbUserName(), $centerDb->getDbUserPass());
            // Versión Servidor Linux
            // $result = new PDO("sqlsrv:Server=$server,$port;Database=$dbName",$centerDb->getDbUserName(), $centerDb->getDbUserPass());
        } else {
            $result = null;
        }

        return $result;
    }