php - Symfony2 changing the values of an item and saving them back in backend -

i need create function changes value gets backend , sends new value backend...

this created far. current stock of product(which 50 in example): check if stock larger quantity of product , if increase quantity 1, , remove 1 value stock. @ end save cart , save new stock(i think). not work , still having 50 in stock.

public function addaction($id)     {         $em = $this->getdoctrine()->getmanager();         $product = $em->getrepository('mpshopbundle:product')->find($id);                $qtyavailable = $product->getstock();        // check cart         $session = $this->getrequest()->getsession();         $cart = $session->get('cart', array());            if( isset($cart[$id]) ) {  // check if array has productid                  if ( $qtyavailable > $cart[ $id ]) {                      $cart[ $id ] = $cart[ $id ] + 1;                     $qtyavailable = $qtyavailable - 1;                 } else {                  return $this->redirect($this->generateurl('cart'));             }           } else {             // if doesnt make 1             $cart = $session->get('cart', array());             $cart[$id] = 1;         }         $product->setstock('qtyavailable', $qtyavailable);         $session->set('cart', $cart);         return $this->redirect( $this->generateurl('cart') );     }  

usually need give value doctrine entity setter.

$product->setstock('qtyavailable', $qtyavailable); 

should be

$product->setstock($qtyavailable); 

if don't have custom code in setstock() method.

also, need call

$em->persist($product); $em->flush(); // runs query on database. 

after set new stock.