Question

Ok I can’t seem to figure this one out..I have 1 table which has column id, parentid
this allows an option to have a sub-option. So it would be something like this:

id  |  parentid
1   |    null
2   |    null
3   |      1 

How I need it to show in my gridview is like this:

id  |  parentid
 1  |     null
 3  |      1
 2  |     null

any ideas I would be most greatful..and just in case I have searched and tried Sql COALESCE on the select but that didn’t work either..

Answer 1

I would use a ListView or DataList instead of a GridView. This should put you on the right path:

<table width="595px">
    <asp:DataList BackColor="#ffffff" id="DataList1" DataKeyField="<ID>" OnItemDataBound="DataList1_ItemDataBound" runat="server" Width="100%">     
        <ItemTemplate>
           <tr>
              <td>
                  <asp:LinkButton ID="LinkButton1" runat="server" Text="+" OnCommand="LinkButton1_Command" CommandArgument='<%#Container.ItemIndex%>'></asp:LinkButton>    
              </td>
              <td><%#Eval("<COLUMN NAME>")%></td>
              <td><%#Eval("<COLUMN NAME>")%></td>
              <td><%#Eval("<COLUMN NAME>")%></td>
           </tr>
           <asp:PlaceHolder ID="plcChildView" runat="server">
               <asp:DataList ID="DataList2" runat="server" Width="100%">
                   <ItemTemplate>
                       <tr>
                          <td><%#Eval("<CHILD OLUMN NAME>")%></td>
                          <td><%#Eval("<CHILD COLUMN NAME>")%></</td>
                          <td><%#Eval("<CHILD COLUMN NAME>")%></</td>                           
                       </tr>
                   </ItemTemplate>
               </asp:DataList>
           </asp:Panel>
        </ItemTemplate>
    </asp:DataList>
</table>

And when the user clicks the LinkButton/Button in DataList1, do something like this:

protected void LinkButton1_Command(object sender, CommandEventArgs e)
{
    //pass index of item in command argument
    int itemIndex = Convert.ToInt32(e.CommandArgument);      

    //find the pnlChildView control
    PlaceHolder childViewHolder = (PlaceHolder)DataList1.Items[itemIndex].FindControl("plcChildView");
    if (childViewHolder != null)
    {
        //toggle visibility of childViewPanel and bind child list if panel is visible

        if (childViewHolder.Visible)
        {
            DataList childList = childViewHolder.FindControl("DataList2");
            if (childList != null)
            {
                int keyValue = (int)DataList1.DataKeys[itemIndex];

                //bind the list using DataList1 data key value
                childList.DataSource = <DATA SOURCE>; //get data using keyValue
                childList.DataBind();
            }  
        }
    }
}