I use this code in my twitch bot to count messages and save them to a database a couple times per minute.

So the current code I have does get the values I want from my database, but I cannot update or insert the values correctly. The insert\_cmd does execute, but values in the database does not correspond to the values I try to insert. 
affectedRows does return the correct answer of rows that should have been affected. Also when I write out the insert\_cmd string, it does look right.

```
     private static void update_messages()
    {
        try
        {
            MySql.Data.MySqlClient.MySqlConnection mysql_connection = new MySql.Data.MySqlClient.MySqlConnection();
            mysql_connection.ConnectionString = mysql_connection_string;
            mysql_connection.Open();

            //build query string
            string select_cmd = "SELECT * FROM taperen.messages where username in (";
            foreach(CountData cd in chat_messages)
            {
                //Console.WriteLine(cd.username);
                select_cmd += "\'" + cd.username + "\',";
            }
            if(select_cmd == "SELECT * FROM taperen.messages where username in (")
            {
                mysql_connection.Close();
                return;
            }
            select_cmd = select_cmd.TrimEnd(select_cmd[select_cmd.Length - 1]);
            select_cmd += ");";
            //Console.WriteLine(select_cmd);

            MySql.Data.MySqlClient.MySqlCommand myCommand = mysql_connection.CreateCommand();
            myCommand.CommandText = select_cmd;
            MySql.Data.MySqlClient.MySqlDataReader reader = myCommand.ExecuteReader();

            string insert_cmd = "";
            while (reader.Read())
            {
                string username = reader["username"].ToString();
                int index = chat_messages.FindIndex(x => x.username.Equals(username));

                int current_online_count = chat_messages[index].online_count;
                int current_offline_count = chat_messages[index].offline_count;

                int db_online_count = (int)reader["online_count"];
                int db_offline_count = (int)reader["offline_count"];

                int new_online_count = current_online_count + db_online_count;
                int new_offline_count = current_offline_count + db_offline_count;
                insert_cmd += $"UPDATE `taperen`.`messages` SET `online_count`='{new_online_count}', `online_count`='{new_offline_count}' WHERE `id`='{reader["id"]}';";

                chat_messages.RemoveAt(index);
                //Console.WriteLine(username);
            }
            reader.Close();
            mysql_connection.Close();
            foreach(CountData cd in chat_messages)
            {
                insert_cmd += $"INSERT INTO `taperen`.`messages` (`username`, `online_count`, `offline_count`) VALUES ('{cd.username}', '{cd.online_count}', '{cd.offline_count}');";
            }

            mysql_connection.Open();

            //Console.WriteLine(insert_cmd);

            myCommand.CommandText = insert_cmd;
            int affectedRows = myCommand.ExecuteNonQuery();
            Console.WriteLine(affectedRows);
            myCommand.Dispose();

            mysql_connection.Close();
        }
        catch (MySql.Data.MySqlClient.MySqlException ex)
        {
            Console.WriteLine(ex.Message);
        }
    }

```

The CountData class looks like this:

```
public class CountData
{
    public string username { get; set; }
    public int online_count { get; set; }
    public int offline_count { get; set; }
}

```

The database looks like this: ![database](https://i.imgur.com/jkOPWLe.png)

Also if I do something else stupid in my code I appreciate if you could come with some tips :)