title: Unable to guess how to get a Doctrine instance from the request information for parameter "bookpermit"
body: <p>I am trying to pass multiple parameters dynamically into a route url using @ParamConverter in symfony. Below is my schema structure</p>
  
  <pre><code>bookpermit
  
  id | userfk  | bookfk   |
  1  | 6       | 6        |
  2  | 6       | 7        |
  3  | 7       | 7        |
  4  | 8       | 8        |
  books
  
  id | name  | uerfk   |
  1  | xyz1   | 6       |
  2  | xyz2   | 7       |
  3  | xyz3   | 8       |
  </code></pre>
  
  <p>Below is the snippet of my routing.yml file</p>
  
  <pre><code>display_book_by_permission:
      pattern:  /displaybookbypermission/{user}
      defaults: { _controller:  xxxBundle:Books:display, _format: ~ }
      requirements:
          _method: GET
  </code></pre>
  
  <p>I removed the arguments for bookpermit since I want to be fetched dynamically from the database</p>
  
  <p>Below is my controller definition containing the paramconverter</p>
  
  <pre><code> /**
   * @Route("/displaybookbypermission/{user}/{bookpermit}")
   * @ParamConverter("user", class="xxxxBundle:Users")
   * @ParamConverter("bookpermit", class="xxxxBundle:BookPermit")
   * @Template()
   */
  public function displayAction(Request $request, $user, $bookpermit)
      {
           $em = $this-&gt;getDoctrine()-&gt;getManager();
      $bookLists= $em-&gt;getRepository("xxxBundle:Books")-&gt;findBy(
          array(
              "usersfk" =&gt; $user,
              "usersfk" =&gt; $bookpermit
          )
      );
  
      $data = array();
  
      foreach ($bookLists as $bookList)
      {
  
          array_push($data, $this-&gt;serialize($bookLists));
      }
  
  
      $response = new Response(json_encode($data), 200);
      $response-&gt;headers-&gt;set('Content-Type', 'application/json');
  
      return $response;
      }
  </code></pre>
  
  <p>My attempt in doing this is to be able to return this result <code>xyz2+xyz1</code> when the url is called</p>
  
  <pre><code>http://localhost:88/books/web/app_dev.php/displaybookbypermission/6
  </code></pre>