Composite Key in DataKeyField of DataGrid 2

[PankajVerma]

Hi,
I am populating a datagrid with the data from a table which has the primary key as the combination of 3 columns.Please let me know how to set that in DataKeyField of the DataGrid. Without setting it I am not able to identify the row I have selected.

Pankaj

 

[LV]

There is couple of ways of doing this. First is to combine the three primary keys columns in one, set the DataKey property to this "made up" key and then extract them in the event handler. Or, set the first field as DataKey in the grid and bind the other two keys to hidden columns in the grid. The second way is probably easier(assumming that all three fields are integers):

html:
<asp:DataGrid ID=myGrid Runat=Server DataKeyField=&quot;keyOne&quot; AutoGenerateColumns=False>
 <asp:TemplateColumn Visible=False>
   <ItemTemplate>
    <asp:Label ID=&quot;keyTwoHolder&quot; Runat=Server Text='<%# DataBinder.Eval(Container.DataItem, &quot;keyTwo&quot;).ToString() %>' />
   </ItemTemplate>
 </asp:TemplateColumn>
 <asp:TemplateColumn Visible=False>
   <ItemTemplate>
    <asp:Label ID=&quot;keyThreeHolder&quot; Runat=Server Text='<%# DataBinder.Eval(Container.DataItem, &quot;keyThree&quot;).ToString() %>' />
   </ItemTemplate>
 </asp:TemplateColumn>
 .....
 .....
</asp:DataGrid>

//page code behind ItemCommand event handler:
private void myGrid_ItemCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
 //find first key
 int keyOne = Convert.ToInt32(myGrid.DataKeys[e.Item.ItemIndex]);
 //find second key
 Label lblKeyTwo = (Label)e.Item.FindControl(&quot;keyTwoHolder&quot;);
 int keyTwo = Convert.ToInt32(lblKeyTwo.Text.Trim());
 //find third key
 Label lblKeyThree = (Label)e.Item.FindControl(&quot;keyThreeHolder&quot;);
 int keyThree = Convert.ToInt32(lblKeyThree.Text.Trim());
}

Hope this helps.