ActiveX Control for queryiing a MySql Database

mysql.cs

using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Collections;
using MySql.Data.MySqlClient;
//using System.Data;
using System.Linq;
using System.Threading;
using System.Text;

namespace LIMS
{
    [
        Guid("577EF7BB-7A8E-4DE3-9619-91BC697DEC3B"),
        InterfaceType(ComInterfaceType.InterfaceIsDual),
        ComVisible(true)
    ]




    public interface ILIMSConnector
    {
        [DispId(1)]
        void setConnectionString(string server, 
                                string database, string userID, 
                                string password);
        [DispId(2)]
        string getData(string sqlQuery);
        [DispId(3)]
        void setData(string sqlQuery);

    };
    
    
    
    
    [
        Guid("0467EBEB-F390-4430-AB76-BE3699331A73"),
        ProgId("db.Connector"),
        ClassInterface(ClassInterfaceType.None),
        ComDefaultInterface(typeof(ILIMSConnector)),
        ComVisible(true)

    ]

    public class LIMSConnector : ILIMSConnector
    {
        #region [ILIMSConnector implementation]


        public static string connectionString;
        public static string queryString;

        public void setConnectionString(string server, string database, string userID, string password)
        {

            connectionString = "SERVER=" + server + ";DATABASE=" + database + ";UID=" + userID + ";PASSWORD=" + password + ";";

        }

        public string getData(string sqlQuery)
        {

            queryString = sqlQuery;

            MySqlConnection connection = new MySqlConnection(connectionString);
            MySqlCommand command = connection.CreateCommand();

            command.CommandText = queryString;
            connection.Open();

            string returndata = "";

            MySqlDataReader reader = command.ExecuteReader();

            while (reader.Read())
            {
                for (int i = 0; i < reader.FieldCount; i++)
                {
                    returndata = returndata + reader.GetValue(i).ToString() + ",";

                }

            }

            connection.Close();

            returndata = returndata.Substring(0, returndata.Length - 1);

            return returndata;

        }

        public void setData(string sqlQuery)
        {
            //--Run Query in a new thread 
            //queryString = sqlQuery;
            //ThreadStart sqlJob = new ThreadStart(sqlThread);
            //Thread thread = new Thread(sqlJob);
            //thread.Start();
            MySqlConnection connection = new MySqlConnection(connectionString);
            MySqlCommand command = connection.CreateCommand();

            //command.CommandText = "insert into absorbance(elisa_barcode, phage_barcode, order_id, absorbace) values('ex100','pp,100','10001',0.1234);";
            command.CommandText = sqlQuery;
            connection.Open();
            command.ExecuteNonQuery();
            connection.Close();


        }





        public static void sqlThread()
        {

            //MySqlConnection connection = new MySqlConnection(connectionString);
            //MySqlCommand command = connection.CreateCommand();

            //command.CommandText = queryString;

            //connection.Open();
            //command.ExecuteNonQuery();
            //connection.Close();



        }



        #endregion

    };

}