Date checker Symfony2

 if ($form->isValid()) {
            $em = $this->getDoctrine()->getManager();
            $bookEntity = $em->getRepository("AppBundle:book")->findBy(array("date" => $req->getDate()));

            if (count($bookEntity) == 0) {
                $em->persist($req);
                $em->flush();
                return $this->redirectToRoute("homepage");
            }elseif(count($bookEntity) == 1){
              //  return new Response ('Er is al iets gepland');
                echo "Error";
            }
        }