Ondalık sayıların veritabanına eklenmemesi

{"itf":"1,5","opr":"success","sipid":"191","sifre":"xxxxxxxxxxxx","transfer":"191","itt":"1,5"}

        $database = DatabaseFactory::getFactory()->getConnection();
        $add = $database->prepare('UPDATE users SET balance = balance + :amount WHERE user_id = :userid');
        $add->execute(array(
            ':userid' => $UserID,
            ':amount' => $UrunTutari

        ));
AffiliateModel::rewardReferrer($UserID, $_POST["itf"]);
        $addtran = $database->prepare('INSERT INTO transactions (user_id, payment_id, complete, created, amount, method) VALUES (:userid, :payment, :complete, :created, :amount, :method)');
        $addtran->execute(array(
            ':userid' => $UserID,
            ':payment' => '',
            ':complete' => 1,
            ':created' => date('Y-m-d H:i:s'),
            ':amount' => $OdemeTutari,
            ':method' => 'BuyPayer'
        ));