Display Country Currency Using PHP and MySQL for IPv6

/****************************************************************************************************************/
/* Description: This snippet is provide simple way to help user display Visitor's Country Currency.             */
/*              suggestions for different city locations across the country.                                    */
/*              There are 1 steps in this snippet. For information, please visit IP2Location tutorial page at:  */
/* https://www.ip2location.com/tutorials/display-visitors-country-currency-using-php-and-mysql-database         */
/****************************************************************************************************************/
/* You can obtain free IP Country database for IPv6 at https://lite.ip2location.com/database/ip-country         */
/* You can obtain free country information data at https://www.ip2location.com/free/country-information         */

<?php
    // Replace this MYSQL server variables with actual configuration
    $mysql_server = "mysql_server.com";
    $mysql_user_name = "UserName";
    $mysql_user_pass = "Password";

    // Retrieve visitor IP address from server variable REMOTE_ADDR
    $ipaddress = $_SERVER['REMOTE_ADDR'];

    // Convert IP address to IP number for querying database
    $ipno = Dot2LongIPv6($ipaddress);

    // Connect to the database server
    $link = mysqli_connect($mysql_server, $mysql_user_name, $mysql_user_pass) or die("Could not connect to MySQL database");

    // Connect to the IP2Location database
    mysqli_select_db($link,"ip2location") or die("Could not select database");

    // SQL query string to match the recordset that the IP number fall between the valid range
    $query = "SELECT * FROM ip_country WHERE $ipno <?= ip_to LIMIT 1";

    // Execute SQL query
    $result = mysqli_query($link,$query) or die("IP2Location Query Failed");

    // Retrieve the recordset (only one)
    $row = mysqli_fetch_assoc($result);

    // Keep the country information into two different variables
    $country_code = $row['country_code'];
    $country_name = $row['country_name'];

    // SQL query string to match the recordset that the tld with Country Short Name
    $query = "SELECT * FROM ip2location_country_information WHERE country_code ='$country_code'";

    // Execute SQL query
    $result = mysqli_query($link,$query) or die("IP2Location Query Failed");

    // Retrieve the recordset (only one)
    $row = mysqli_fetch_assoc($result);

    // Keep the Currency name in a variable
    $currency_name = $row['currency_name'];

    // Free recordset and close database connection
    mysqli_free_result($result);
    mysqli_close($link);

    // Display currency information
    echo "The IP address : $ipaddress<?br/><?br/>";
    echo "Visitor From : $country_name<?br/><?br/>";
    echo "Your Currency is : $currency_name<?br/><?br/>";

    exit;

    // Function to convert IP address to IP number (IPv6)
    function Dot2LongIPv6 ($IPaddr) {
        $int = inet_pton($IPaddr);
        $bits = 15;
        $ipv6long = 0;
        while($bits >= 0){
            $bin = sprintf("%08b", (ord($int[$bits])));
            if($ipv6long){
                $ipv6long = $bin . $ipv6long;
            }
            else{
                $ipv6long = $bin;
            }
            $bits--;
        }
        $ipv6long = gmp_strval(gmp_init($ipv6long, 2), 10);
        return $ipv6long;
    }
?>