Shakib

function generateOrderId($customerID = null)
{
    $six_digit_random_number = mt_rand(100000, 999999);

    $orderID = 'Q-' . $customerID . '-' . $six_digit_random_number;

    $orderIDCheck = DB::table('orders')
        ->select('order_id')
        ->where('order_id', '=', $orderID)
        ->first();

    if ($orderIDCheck) {

        return generateOrderId($customerID);

    } else {

        return $customerID;

    }
}