How to implement insert/update/delete in GridView for List with Lookup and Choice columns?

<asp:GridView ID="GridView1" runat="server" EnableTheming="False" OnRowCreated="GridView1_RowCreated">

            <Columns>

                <asp:TemplateField>

                    <ItemTemplate>

                        <asp:DropDownList ID="DropDownList1" runat="server">

                        </asp:DropDownList>

                    </ItemTemplate>

                </asp:TemplateField>

            </Columns>

</asp:GridView>

protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)

  {

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

            {

                DataTable dt = new DataTable("nameList");

                dt.Columns.Add("name");

                SPSite site = new SPSite("http://jack-7716f30e37:80");

                using (SPWeb Web = site.OpenWeb())

                {

                    SPList mylist = Web.Lists["MyList"];

                    SPQuery query = new SPQuery();

                    SPListItemCollection items = mylist.GetItems(query);

                    foreach (SPListItem item in items)

                    {

                        DataRow row = dt.NewRow();

                        row["name"] = item["Title"];

                        dt.Rows.Add(row);

                    }

                }

                ((DropDownList)e.Row.FindControl("DropDownList1")).DataSource = dt;

                ((DropDownList)e.Row.FindControl("DropDownList1")).DataTextField = "name";

                ((DropDownList)e.Row.FindControl("DropDownList1")).DataBind();

            }

}