Instead of hard coding the parameters in `parameters.yml` I am trying to load them from database. Not all parameters in parameters.yml needs to be loaded from database just a few, like api details of paypal

In `config.yml` I have imported the `parameters.php`

```
imports:
    - { resource: parameters.php }

```

If I add static information in `parameters.php` like the one below it works fine

```
$demoName = 'First Last';
$container->setParameter('demoName', $demoName);

```

However I am not able to fetch information from database table. I thought i should create class and make use of `$em = this->getDoctrine()->getManager();` and it should work but it doesn't and i get the error of 

`Notice: Undefined variable: paypal_data in /opt/lampp/htdocs/services/app/config/parameters.php (which is being imported from "/opt/lampp/htdocs/services/app/config/config.yml").`

This is the attempt i made is as following but the code does not seem to go in `__construct()`

```
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Doctrine\Bundle\DoctrineBundle\Registry;
use Doctrine\ORM\Mapping as ORM;

class parameters extends Controller
{
    public $paypal_data;

    function __construct() {
        $this->indexAction();
    }

    public function indexAction(){

        $em = $this->getDoctrine()->getManager();
        $this->paypal_data = $em->getRepository('featureBundle:paymentGateways')->findAll();

    }

}
$demoName = 'First Last';
$container->setParameter('demoName', $demoName);
$container->setParameter('paypal_data', $this->paypal_data);

```

Any help will be much appreciated.