php - Symfony 2 "findBy" a mapped entity parameter into controller -

i'm new symfony2 , know whether there way use "findby" param present in mapped entity.

this snippet controller:

$prods = $em->getrepository('ecommerceproductbundle:productdata')     ->findby(array(         'product_id'=>46     )); 

it works if try add element array, present in mapped entity, (rightly) error

unrecognized field: productimage.is_visible   

what do, know wehether can use "filterby" mapped element of entity productdata.

i'm in wrong idea:

->findby(array(   'product_id'=>46,   'productimage.is_visible'=>1     )); 

not possible far know. add custom method repository:

public function findbyidandvisibleimage($id) {     return $this->createquerybuilder('product')         ->lefjoin("product.image","i")         ->where("product.product_id = :id")         ->andwhere("i.is_visible = 1")          ->setparameter("id", $id)         ->getquery()         ->getsingleresult();  }