public static function withoutName()
 {
     $db = DBConnect::getDB();
     $devices = $db->prepare("SELECT MAC_Address FROM Users WHERE Name IS NULL");
     $devices->execute();
     $row = $devices->fetchAll(\PDO::FETCH_ASSOC);
     $without_Name = $row;
     return $without_Name;
 }
 public static function addusername($username, $mac_address)
 {
     $db = DBConnect::getDB();
     $device = $db->prepare("UPDATE Users SET Name = :username WHERE MAC_Address = :mac_address");
     $par = array(":username" => $username, ":mac_address" => $mac_address);
     $device->execute($par);
     $row = $device->fetch();
     if ($row) {
         return true;
     } else {
         return false;
     }
 }