C# MySQL second DataReader in DataReader while loop

Question

As you might have guessed from the title am I trying to do this:

    #region check new nations
    private void checknewnations()
    {
        addtolog("server","Checking for new nations");
        string sql = "SELECT * FROM " + variables.tbl_nations + " WHERE nations_new=0";
        MySqlCommand cmd = new MySqlCommand(sql, connection);
        MySqlDataReader reader = cmd.ExecuteReader();

        while (reader.Read())
        {
            addtolog("mysql",reader["nations_name"].ToString());

            int nation_ID = int.Parse(reader["nations_ID"].ToString());
            string nation_name = reader["nations_name"].ToString();
            string user_ID = reader["nations_user"].ToString();


            addnation(nation_ID, nation_name, user_ID);
        }
        addtolog("server","Finished checking for new nations.");
        //connection.Close();
        reader.Dispose();
    }
    #endregion

which calls this in the while loop:

    #region addnation
    private void addnation(int nationIDnot, string nationName, string userID)
    {
        string nationID = makesixdigits(nationIDnot);
        string userName = "";

        string sql = "SELECT * FROM " + variables.tbl_users + " WHERE users_ID=" + userID;
        MySqlCommand cmd = new MySqlCommand(sql, connection);
        MySqlDataReader reader = cmd.ExecuteReader();


        while (reader.Read())
        {
            userName = reader["users_name"].ToString();
        }
        reader.Dispose();
        addtolog("add", "[" + nationID.ToString() + "] " + nationName + " [" + userID + "] " + userName);
    }
    #endregion

This gives me an error in the second block of code (the one that is called upon in the while loop) saying that there already is a datareader associated with the connection. How am I to get this to work, because I am sure there is a way.

Answer 1

DataReader holds on to connection until it iterates through all its records. Try this

using(reader)
{
   System.Data.DataTable dt = new System.Data.DataTable();
   dt.Load(reader);

   foreach(DataRow row in dt.Rows)
   {
        addtolog("mysql",row["nations_name"].ToString());

        int nation_ID = int.Parse(row["nations_ID"].ToString());
        string nation_name = row["nations_name"].ToString();
        string user_ID = row["nations_user"].ToString();


        addnation(nation_ID, nation_name, user_ID);
   }
}

This way the two reader are not sharing the same connection