You need to replace TemplateField with BoundField
You can see the GridView in the article
Using SqlBulkCopy to insert bulk data from GridView to database in ASP.Net
Its having BoundField for Id, Name, Country that needs to be added in the Database.
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false">
<Columns>
<asp:TemplateField>
<ItemTemplate>
<asp:CheckBox ID="CheckBox1" runat="server" />
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="Id" HeaderText="Id" ItemStyle-Width="30" />
<asp:BoundField DataField="Name" HeaderText="Name" ItemStyle-Width="150" />
<asp:BoundField DataField="Country" HeaderText="Country" ItemStyle-Width="150" />
</Columns>
</asp:GridView>