Create individual files from mysql query results

hello, can anyone help me with this one?

I have made a mysql connection and results display, however i need to create a txt tile for each result, with the result as file name

Example:

mysql query returns "123123123", then file 123123123.txt woud be created.

here is my code as it stands

string[] filePaths = Directory.GetFiles(@"C:\Users\travi\Desktop\customers\Active");
foreach (string filePath in filePaths)
File.Delete(filePath);
string serverIp = "localhost";
string username = "root";
string password = "";
string databaseName = "teste";
string dbConnectionString = string.Format("server={0};uid={1};pwd={2};database={3};", serverIp, username, password, databaseName);
string query = "SELECT ID FROM `wp_posts` WHERE `post_type` = 'shop_subscription' and post_status = 'wc-active'";
var conn = new MySql.Data.MySqlClient.MySqlConnection(dbConnectionString);
conn.Open();
var cmd = new MySql.Data.MySqlClient.MySqlCommand(query, conn);
var reader = cmd.ExecuteReader();
while (reader.Read())
{
var subs = reader["ID"];
// how to create individual files from each result