$stmt = $app['orm.em']->getConnection()->prepare('delete from plg_hsd_related_product order by updated_at asc limit ' . $del_rows);
                $stmt->execute();

                $stmt = $app['orm.em']->getConnection()->prepare("
                        SELECT rp.id as id FROM plg_hsd_related_product rp order by updated_at asc limit
                    " . $del_rows);
                $stmt->execute();
                $rs = $stmt->fetchAll();
                foreach($rs as $item){
                    $stmt = $app['orm.em']->getConnection()->prepare('delete from plg_hsd_related_product where id = "' . $item['id'] . '"');
                    $stmt->execute();
                }