Return Multiple Columns on MySQL Queries

I have a MySQL Connection that works, but I can only 1 column per query. Here is my Connection Class:

    class clsMySqlODBCConnection
    {
        public int QueryType = 0;
        public System.Data.Odbc.OdbcConnection OdbcCon;
        public System.Data.Odbc.OdbcCommand OdbcCom;
        public System.Data.Odbc.OdbcDataReader OdbcDR;
        public string ConStr;
        private string MySqlServer = "linux02", MySqlPort = "", MySqlDatabase = "EbtronSystems", MySqlUser = "ebtron", MySqlUserPass = "ebtron", MySqlOption = "3";

        public clsMySqlODBCConnection()
        {
            ConStr = "DRIVER={MySQL ODBC 3.51 Driver};SERVER=" + MySqlServer + ";PORT=" + MySqlPort + ";DATABASE=" + MySqlDatabase + ";UID=" + MySqlUser + ";PWD=" + MySqlUserPass + ";OPTION=" + MySqlOption + "";
            OdbcCon = new System.Data.Odbc.OdbcConnection(ConStr);
           
            try
            {
                //txtLog.AppendText("Openning connection...\r\n");
                if (OdbcCon.State == ConnectionState.Closed)
                {
                    OdbcCon.Open();
                }
                //txtLog.AppendText("Connection opened\r\n");
                //MessageBox.Show("Connection opened\r\n");
            }
            catch (System.Data.Odbc.OdbcException Ex)
            {
                //txtLog.AppendText(Ex.Message + "\r\n");
                //MessageBox.Show("Could not access the database.\r\nPlease make sure you completed the fields with the correct information and try again.\r\n\r\nMore details:\r\n" + Ex.Message, "Database connection error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        public void MySqlDisconnection()
        {
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCon.Close();
                //MessageBox.Show("Connected Closed\r\n");
            }
        }

        public string[] MySQLQuery(string qry, int fldidx)
        {
            List<string> list = new List<string>();

            string tStr = null;     // the following is not needed: = Convert.ToString(null);
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCom = new System.Data.Odbc.OdbcCommand(qry, OdbcCon);
                if (fldidx >= 0)
                {
                    OdbcDR = OdbcCom.ExecuteReader();
                    while (OdbcDR.Read())
                    {
                        tStr = Convert.ToString(OdbcDR[fldidx]);
                        list.Add(tStr);
                    }
                }
                else
                {
                    OdbcCom.ExecuteNonQuery();
                    QueryType = 1;
                }
            }
            return list.ToArray();
        }
        public void MySQLNONQuery(string qry)
        {
            if (OdbcCon.State == ConnectionState.Open)
            {
                OdbcCom = new System.Data.Odbc.OdbcCommand(qry, OdbcCon);
                OdbcCom.ExecuteNonQuery();
                QueryType = 1;
            }
        }

        public object InitializeCnnObject()
        {
            // Create and initilize a recordset to represent the User Table
            clsMySqlODBCConnection OpenConnection = new clsMySqlODBCConnection();
            return OpenConnection;
        }
    }
////////////////////


I run a query like this:

string[] strQryResults = null;

strQryResults = OpenConnection.MySQLQuery("SELECT * FROM AdvantageOrderForm WHERE ItemIndexNumber = '" + tmpItemIndexNumber + "'", 0);

I can return only one column I have to run another query in order to get another column:

strQryResults = OpenConnection.MySQLQuery("SELECT * FROM AdvantageOrderForm WHERE ItemIndexNumber = '" + tmpItemIndexNumber + "'", 1);

I have a table with more than 50 columns, it takes nearly a minute to run all those queries. I need to be able to run 1 query and be able to get results for all the columns.

I know this is all because of my function:
public string[] MySQLQuery(string qry, int fldidx)

But I'm pretty new to DotNet and also to C#, so I'm not sure how to make it work.

Thanks for any help