Update, Delete in gridview

Insert/update in datagridview by clicking the cell and then clicking insert/update and delete buttons

App.xml file

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Data.OleDb;

namespace Update_delete_datagridview

{

    public partial class Form1 : Form

    {

       OleDbDataAdapter oledbda;

       OleDbCommandBuilder olcb;

       DataTable dataTable;

       BindingSource bindingSource;

       string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];

       string str;

        public Form1()

        {

            InitializeComponent();

        }

        private void Form1_Load(object sender, EventArgs e)

        {

            OleDbConnection con = new OleDbConnection(ConnectionString);

            con.Open();

            str = "SELECT * FROM student";

            oledbda = new OleDbDataAdapter(str, con);

            olcb = new OleDbCommandBuilder(oledbda);

            dataTable = new DataTable();

            oledbda.Fill(dataTable);

            con.Close();

            bindingSource = new BindingSource();

            bindingSource.DataSource = dataTable;

            dataGridView1.DataSource = bindingSource;

            dataGridView1.Columns[0].Visible = false;

        }

        private void btnaddupdate_Click(object sender, EventArgs e)

        {

            try

            {

                oledbda.Update(dataTable);

            }

            catch (Exception exceptionObj)

            {

                MessageBox.Show(exceptionObj.Message.ToString());

            }

            MessageBox.Show("Records updated");

        }

        private void btndelete_Click(object sender, EventArgs e)

        {

            try

            {

                dataGridView1.Rows.RemoveAt(dataGridView1.CurrentRow.Index);

                oledbda.Update(dataTable);

            }

            catch (Exception exceptionObj)

            {

                MessageBox.Show(exceptionObj.Message.ToString());

            }

            MessageBox.Show("Records Deleted");

        }

    }

}