Step 1: Download IP2Location LITE database, unzip the file follow the instruction in order to create database table. Please refer to DB11 LITE for further information.

Step 2: Download the demo project and include into your C Sharp project.

Reading IP addresses and querying in bulk

void DisplayFileContents(HttpPostedFile file)
{
    Stream theStream = FileUpload1.PostedFile.InputStream;
    StringBuilder display = new StringBuilder();
    using (StreamReader sr = new StreamReader(theStream))
    {
        string line;
        char[] delimiter1 = new char[] { ',' };
 
        while ((line = sr.ReadLine()) != null)
        {
            string[] iplist = line.Split(delimiter1, StringSplitOptions.None);
 
            foreach (string IP in iplist)
            {
                display.Append("IP Address : " + IP.ToString() + "\n");
 
                string ip_addr = IP;
 
                System.Numerics.BigInteger ip_num = ip_to_number(ip_addr);
                String ip_no = ip_num.ToString();
                string query = "SELECT country_code, country_name , city_name , region_name, latitude,longitude,zip_code,time_zone FROM ip2location_db11 WHERE ip_to >= " + ip_no + " order by ip_to limit 1";
                string[] data = Get_Data(query);
 
                string country_code = data[0];
                string country_name = data[1];
                string city_name = data[2];
                string region_name = data[3];
                string latitude = data[4];
                string longitude = data[5];
                string zip_code = data[6];
                string time_zone = data[7];
 
                //Define the result file that you want to output
                string filePath = Server.MapPath("~") + "result.csv";
 
                using (StreamWriter Sw = File.AppendText(filePath))
                {
                    string output = string.Format("\"" + IP + "\"" + "," + "\"" + country_code + "\"" + "," + "\"" + country_name + "\"" + "," + "\"" + city_name + "\"" + "," + "\"" + region_name + "\"" + "," + "\"" + latitude + "\"" + "," + "\"" + longitude + "\"" + "," + "\"" + zip_code + "\"" + "," + "\"" + time_zone + "\"");
 
                    Console.WriteLine(output);
                    Sw.WriteLine(output);
 
                }
                Label3.Text = "Result File Path : " + Path.GetFullPath(filePath) + "<br>";
            }
        }
    }
 
    Label4.Text = "Please DELETE the result file if you want to upload a new file! <br>";
 
}

Retrieving data

public static string[] Get_Data(string query)
{
    //Database connection string, replace lower capital with MySQL settings
    string db_con_string = "SERVER=server;DATABASE=database;UID=userid;PASSWORD=password;";
    using (MySqlConnection con = new MySqlConnection(db_con_string))
    {
        using (MySqlCommand cmd = new MySqlCommand())
        {
            cmd.CommandText = query;
            using (MySqlDataAdapter sda = new MySqlDataAdapter())
            {
                cmd.Connection = con;
                sda.SelectCommand = cmd;
                using (DataSet ds = new DataSet())
                {
                    DataTable dt = new DataTable();
                    sda.Fill(dt);
                    object country_code = dt.Rows[0]["country_code"];
                    object country_name = dt.Rows[0]["country_name"];
                    object region_name = dt.Rows[0]["region_name"];
                    object city_name = dt.Rows[0]["city_name"];
                    object latitude = dt.Rows[0]["latitude"];
                    object longitude = dt.Rows[0]["longitude"];
                    object zip_code = dt.Rows[0]["zip_code"];
                    object timezone = dt.Rows[0]["time_zone"];
                    string[] data = { Convert.ToString(country_code), Convert.ToString(country_name), Convert.ToString(region_name), Convert.ToString(city_name), Convert.ToString(latitude), Convert.ToString(longitude), Convert.ToString(zip_code), Convert.ToString(timezone) };
                    return data;
                }
            }
        }
    }
}

Converting IP address to IP number

System.Numerics.BigInteger ip_to_number(string ip_addr)
{
    System.Net.IPAddress address;
    System.Numerics.BigInteger ipnum = 0;
 
    if (System.Net.IPAddress.TryParse(ip_addr, out address))
    {
        byte[] addrBytes = address.GetAddressBytes();
 
        if (System.BitConverter.IsLittleEndian)
        {
            System.Collections.Generic.List<byte> byteList = new System.Collections.Generic.List<byte>(addrBytes);
            byteList.Reverse();
            addrBytes = byteList.ToArray();
        }
 
        if (addrBytes.Length > 8)
        {
            //IPv6
            ipnum = System.BitConverter.ToUInt64(addrBytes, 8);
            ipnum <<= 64;
            ipnum += System.BitConverter.ToUInt64(addrBytes, 0);
        }
        else
        {
            //IPv4
            ipnum = System.BitConverter.ToUInt32(addrBytes, 0);
        }
    }
    return ipnum;
}</byte></byte>

Download demo project : Lookup IP Address in Bulk.