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

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        string connetionString;
        OleDbConnection connection;
        OleDbDataAdapter oledbAdapter;
        OleDbCommandBuilder oledbCmdBuilder;
        DataSet ds = new DataSet();
        DataSet changes;
        int i;
        string Sql;


        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            connetionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Your mdb filename;";
            connection = new OleDbConnection(connetionString);
            Sql = "select * from tblUsers";
            try
            {
                connection.Open();
                oledbAdapter = new OleDbDataAdapter(Sql, connection);
                oledbAdapter.Fill(ds);
                dataGridView1.DataSource = ds.Tables[0];
            }
            catch (Exception ex)
            {
                MessageBox.Show (ex.ToString());
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                oledbCmdBuilder = new OleDbCommandBuilder(oledbAdapter);
                changes = ds.GetChanges();
                if (changes != null)
                {
                    oledbAdapter.Update(ds.Tables[0]);
                }
                ds.AcceptChanges();
                MessageBox.Show("Save changes");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }
    }
}