The Following Example is Explains How To Update,Delete,Adding(Insert) Record... In GridView

In Coding Page

<asp:GridView ID="GridView1" runat="server" Style="z-index: 100; left: 102px; position: absolute;top: 51px" AutoGenerateColumns="False" AutoGenerateDeleteButton="True" AutoGenerateEditButton="True" DataKeyNames="eno" OnRowCancelingEdit="GridView1_RowCancelingEdit" OnRowCreated="GridView1_RowCreated" OnRowDeleting="GridView1_RowDeleting" OnRowEditing="GridView1_RowEditing" OnRowUpdating="GridView1_RowUpdating" ShowFooter="True" CellPadding="4" ForeColor="#333333" GridLines="None">

<Columns>

<asp:BoundField DataField="eno" HeaderText="EmpNo" ReadOnly="True" SortExpression="eno" />

<asp:BoundField DataField="ename" HeaderText="ename" SortExpression="ename" />

<asp:BoundField DataField="sal" HeaderText="sal" SortExpression="sal" />

Columns>

<FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />

<RowStyle BackColor="#EFF3FB" />

<EditRowStyle BackColor="#2461BF" />

<SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" />

<PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" />

<HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />

<AlternatingRowStyle BackColor="White" />

asp:GridView>

<asp:Button ID="btninsert" runat="server" OnClick="btninsert_Click" Text="Add" Width="68px" style="z-index: 102; left: 103px; position: absolute; top: 25px" />

Set The Following Values in GridView Properties
AutoGenerateColumes=false;
AutoGenerateDelete=True;
AutoGenerateEditButton=true;
Datakeynames=eno;(Primary key coloume name)
ShowFooter=True;

The Following example is used MySql DB;
Example table Is Emp1(eno,ename,sal fields)


In .cs File

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Data.Odbc;

public partial class _Default : System.Web.UI.Page

{

string str;

OdbcConnection myConn

= new OdbcConnection("driver={Mysql odbc 3.51 driver};user id=root;password=admin;server=localhost;database=temp");

protected void Page_Load(object sender, EventArgs e)

{

if (IsPostBack == false)

{

str = "select * from emp1";

getdata(str);

}

}

public void getdata(string s)

{

OdbcDataAdapter da = new OdbcDataAdapter(s, myConn);

DataSet ds = new DataSet();

da.Fill(ds, "raji");

GridView1.DataSource = ds;

GridView1.DataBind();

}

protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)

{

int row = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Value);

OdbcCommand cmd = new OdbcCommand("delete from emp1 where eno=" + row, myConn);

myConn.Open();

cmd.ExecuteNonQuery();

myConn.Close();

getdata("select * from emp1");

}

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)

{

GridViewRow row;

row = GridView1.Rows[e.RowIndex];

TextBox t;

t = (TextBox)row.Cells[2].Controls[0];

string nename = t.Text;

t = (TextBox)row.Cells[3].Controls[0];

int nsal = int.Parse(t.Text);

int eno = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Value);

OdbcCommand cmd = new OdbcCommand("update emp1 set ename='" + nename + "',sal=" + nsal + " where eno=" + eno, myConn);

myConn.Open();

cmd.ExecuteNonQuery();

myConn.Close();

GridView1.EditIndex = -1;

getdata("select * from emp1");

}

protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)

{

GridView1.EditIndex = e.NewEditIndex;

getdata("select * from emp1");

}

protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)

{

GridView1.EditIndex = -1;

getdata("select * from emp1");

}

protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)

{

if (e.Row.RowType == DataControlRowType.Footer)

{

TableCell cell1 = e.Row.Cells[1];

TextBox txteno = new TextBox();

txteno.ID = "txteno";

txteno.Width = 70;

cell1.Controls.Add(txteno);

TableCell cell2 = e.Row.Cells[2];

TextBox txtename = new TextBox();

txtename.ID = "txtename";

txtename.Width = 70;

cell2.Controls.Add(txtename);

TableCell cell3 = e.Row.Cells[3];

TextBox txtsal = new TextBox();

txtsal.ID = "txtsal";

txtsal.Width = 70;

cell3.Controls.Add(txtsal);

}

}

protected void btndelete_Click(object sender, EventArgs e)

{

string ds = "";

foreach (GridViewRow r in GridView1.Rows)

{

CheckBox cb = (CheckBox)r.FindControl("chk1");

if (cb.Checked)

{

int eno = Convert.ToInt32(GridView1.DataKeys[r.RowIndex].Value);

ds = "delete from emp1 where eno=" + eno;

OdbcCommand cmd = new OdbcCommand(ds, myConn);

myConn.Open();

cmd.ExecuteNonQuery();

myConn.Close();

}

}

getdata("select * from emp1");

}

protected void btninsert_Click(object sender, EventArgs e)

{

GridViewRow r = GridView1.FooterRow;

TextBox t;

t = (TextBox)r.FindControl("txteno");

int eno = int.Parse(t.Text);

t = (TextBox)r.FindControl("txtename");

string ename = t.Text;

t = (TextBox)r.FindControl("txtsal");

int sal = int.Parse(t.Text);

OdbcCommand cmd = new OdbcCommand("insert into emp1 values(" + eno + ",'" + ename + "'," + sal + ")", myConn);

myConn.Open();

cmd.ExecuteNonQuery();

cmd.Dispose();

getdata("select * from emp1");

}

}