How to clear the error in update query

Question

HI

 

i am have a grid view with edit,update,delete button edit and delete button is wrking,updated button is nt wrking....in my table i dnt have id columns,here showing negative error on [string id = GridView1.DataKeys[e.RowIndex].Value.ToString();] this line...

hw to clear the error 

 

 

hw to wrk?

 

my query:

 

 

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false"

OnRowCancelingEdit="GridView1_RowCancelingEdit" CellPadding="4" ForeColor="#333333" OnRowDataBound="GridView1_RowDataBound"

OnRowEditing="GridView1_RowEditing" OnRowUpdating="GridView1_RowUpdating" Height="199px" Width="516px">

<Columns>

<asp:TemplateField>

<ItemTemplate>

<asp:LinkButton ID="LkB1" runat="server" CommandName="Edit">Edit</asp:LinkButton>

</ItemTemplate>

<EditItemTemplate>

<asp:LinkButton ID="LB2" runat="server" CommandName="Update">Update</asp:LinkButton>

<asp:LinkButton ID="LB3" runat="server" CommandName="Cancel">Cancel</asp:LinkButton>

</EditItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText = "S.NO" >

<ItemTemplate>

<asp:Label ID="lblRowNumber" runat="server" />

</ItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="HTSC">

<ItemTemplate>

<asp:Label ID="Label1" runat="server" Text='<%# Eval("HTSCNO") %>'></asp:Label>

</ItemTemplate>

<EditItemTemplate>

<asp:TextBox ID="txt_Name" runat="server" Text='<%# Eval("HTSCNO") %>'></asp:TextBox>

</EditItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="ADDRESS1">

<ItemTemplate>

<asp:Label ID="Label2" runat="server" Text='<%# Eval("ADDRESS1") %>'></asp:Label>

</ItemTemplate>

<EditItemTemplate>

<asp:TextBox ID="txt_Branch" runat="server" Text='<%# Eval("ADDRESS1") %>'></asp:TextBox>

</EditItemTemplate>

</asp:TemplateField>

<asp:TemplateField HeaderText="ADDRESS2">

<ItemTemplate>

<asp:Label ID="Label3" runat="server" Text='<%# Eval("ADDRESS2") %>'></asp:Label>

</ItemTemplate>

<EditItemTemplate>

<asp:TextBox ID="txt_City" runat="server" Text='<%# Eval("ADDRESS2") %>'></asp:TextBox>

</EditItemTemplate>

</asp:TemplateField>

</Columns>

<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />

<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />

</asp:GridView>

 

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

{

SqlConnection con = new SqlConnection(@"data source=VAAYUSEVA_SVR;Initial Catalog=cppsch;User ID=sa;Password=sa");

protected void Page_Load(object sender, EventArgs e)

{

if (!IsPostBack)

{

BindGridView();

}

}

protected void BindGridView()

{

DataTable dt = new DataTable();

SqlDataAdapter da = new SqlDataAdapter("Select [USER NAME],HTSCNO,ADDRESS1,ADDRESS2 from TBL_CPPMASTER", con);

con.Open();

da.Fill(dt);

con.Close();

if (dt.Rows.Count > 0)

{

GridView1.DataSource = dt;

GridView1.DataBind();

}

}

protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)

{

GridView1.EditIndex = e.NewEditIndex;

BindGridView();

}

protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)

{

//find student id of edit row

string id = GridView1.DataKeys[e.RowIndex].Value.ToString();

// string un = Session["Uname"].ToString();

TextBox name = (TextBox)GridView1.Rows[e.RowIndex].FindControl("txt_Name");

TextBox branch = (TextBox)GridView1.Rows[e.RowIndex].FindControl("txt_Branch");

TextBox city = (TextBox)GridView1.Rows[e.RowIndex].FindControl("txt_City");

SqlCommand cmd = new SqlCommand("update TBL_CPPMASTER set HTSCNO='" + name.Text + "', ADDRESS1='"+branch.Text+"', ADDRESS2='"+city.Text+"' where [COMPANYNAME]= id", con);

con.Open();

cmd.ExecuteNonQuery();

con.Close();

GridView1.EditIndex = -1;

BindGridView();

}

// cancel row edit event

protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)

{

GridView1.EditIndex = -1;

BindGridView();

}

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)

{

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

{

(e.Row.FindControl("lblRowNumber") as Label).Text = (e.Row.RowIndex + 1).ToString();

}

}

}