using System;
using System.Windows.Forms;
using System.Data.OleDb; 

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string connetionString = null;
            OleDbConnection oledbCnn ;
            OleDbCommand oledbCmd ;
            string sql = null;

            connetionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Your mdb filename;";
            sql = "Your SQL Statement Here like Select * from product";

            oledbCnn = new OleDbConnection(connetionString);
            try
            {
                oledbCnn.Open();
                oledbCmd = new OleDbCommand(sql, oledbCnn);
                OleDbDataReader oledbReader = oledbCmd.ExecuteReader();
                while (oledbReader.Read ())
                {
                    MessageBox.Show(oledbReader.GetValue(0) + " - " + oledbReader.GetValue(1) + " - " + oledbReader.GetValue(2));
                }
                oledbReader.Close();
                oledbCmd.Dispose();
                oledbCnn.Close();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Can not open connection ! ");
            }
        }
    }
}