using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;

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

        private void Form1_Load(object sender, EventArgs e)
        {
            OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Documents and Settings\\Rajesh\\My Documents\\insert1.mdb");
            cn.Open();
            OleDbCommand cd = new OleDbCommand("SELECT DISTINCT name, MIN(id) AS id FROM duplicate GROUP BY name ORDER BY MIN(id)",cn);
            OleDbCommand cdd = new OleDbCommand("select id from duplicate",cn);
            OleDbDataAdapter da = new OleDbDataAdapter();
            OleDbDataAdapter da1 = new OleDbDataAdapter();
            da.SelectCommand = cd;
            da1.SelectCommand = cdd;
            DataSet ds = new DataSet();
            da.Fill(ds,"select1");
            da1.Fill(ds,"select2");

            for (int j = 0; j < ds.Tables["select2"].Rows.Count; j++)
            {
                OleDbCommand cd1 = new OleDbCommand("delete from duplicate where id="+ds.Tables["select2"].Rows[j][0]+"", cn);
                cd1.ExecuteNonQuery();
            }

            for (int i = 0; i < ds.Tables["select1"].Rows.Count; i++)
            {
                OleDbCommand cd2 = new OleDbCommand("insert into duplicate(id,name) values('"+ds.Tables["select1"].Rows[i][1].ToString()+"','"+ds.Tables["select1"].Rows[i][0].ToString()+"')", cn);
                cd2.ExecuteNonQuery();

            }
            dataGridView1.DataSource = ds.Tables["select1"];

        }
    }
}