row update button coding in grid view for asp.net c#

Question

i have use this part of code for update a row in gridview in c# asp.net

in my past project it was worked but now it is not working can anybody help me in this i have pase my sql query, asp gridview code and my logical code too

please advise me how to update a row in gridview

SQL Query

create database test

use test

create table gridview(id int identity(1,1),ename varchar(50),city varchar(50))

insert into gridview values('nitin','hisar')

insert into gridview values('deepak','gwalior')

insert into gridview values('raman','delhi')

select*from gridview

update gridview set ename='nitin sharma', city='haryana' where id=1

 

default.aspx

<asp:GridView ID="GridView1" runat="server" Height="189px" Width="332px"

AutoGenerateDeleteButton="True" AutoGenerateEditButton="True" DataKeyNames="id"

onrowcancelingedit="GridView1_RowCancelingEdit"

onrowdeleting="GridView1_RowDeleting" onrowediting="GridView1_RowEditing"

onrowupdating="GridView1_RowUpdating">

</asp:GridView>

 

default.aspx.cs

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)

{

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

string name=GridView1.Rows[e.RowIndex].Cells[0].Text;

string city=GridView1.Rows[e.RowIndex].Cells[1].Text;

if (con.State == ConnectionState.Closed)

{

con.Open();

}

SqlCommand cmd = new SqlCommand("update gridview set ename='"+name+"', city='"+city+"' where id='"+id+"'", con);

cmd.ExecuteNonQuery();

con.Close();

GridView1.DataBind();

display();

}

please help me