Sometimes it is helpful to know the parent item primary key value when updating/inserting child records in grid hierarchy - for example, to refresh the parent row on update
action as well (when certain conditions are met) or to hide some edit field in the child insertion form for specific parent item. Below are the steps which can be
followed to fetch the parent row primary field in these situations:
- wire the ItemCommand event of the grid
- in case e.CommandName is RadGrid.UpdateCommandName the e.Item.OwnerTableView.ParentItem instance will point to the
item from the parent table to which the child records belong.
- if e.CommandName is RadGrid.InitInsertCommandName or RadGrid.PerformInsertCommandName the case is identical - once
again e.Item.OwnerTableView.ParentItem will reference the parent table row.
The code section shows how to get the primary key field for up-level rows using DataKeyNames/DataKeyValues:
| ASPX/ASCX |
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<telerik:RadGrid ID="RadGrid1" DataSourceID="AccessDataSource1" runat="server" Skin="Desert"
Width="95%" AutoGenerateColumns="False" PageSize="3" AllowSorting="True"
AllowPaging="True"
>
<PagerStyle Mode="NumericPages"></PagerStyle>
<MasterTableView DataSourceID="AccessDataSource1" DataKeyNames="CustomerID" Width="100%">
<DetailTables>
<telerik:GridTableView DataKeyNames="OrderID" DataSourceID="AccessDataSource2" Width="100%"
runat="server" CommandItemDisplay="Top">
<ParentTableRelation>
<telerik:GridRelationFields DetailKeyField="CustomerID" MasterKeyField="CustomerID" />
</ParentTableRelation>
<Columns>
<telerik:GridBoundColumn SortExpression="OrderID" HeaderText="OrderID" HeaderButtonType="TextButton"
DataField= "OrderID" UniqueName="OrderID">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="OrderDate" HeaderText="Date Ordered" HeaderButtonType="TextButton"
DataField= "OrderDate" UniqueName="OrderDate">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="EmployeeID" HeaderText="EmployeeID" HeaderButtonType="TextButton"
DataField= "EmployeeID" UniqueName="EmployeeID">
</telerik:GridBoundColumn>
<telerik:GridEditCommandColumn UniqueName="EditCommandColumn" />
</Columns>
</telerik:GridTableView>
</DetailTables>
<Columns>
<telerik:GridBoundColumn SortExpression="CustomerID" HeaderText="CustomerID" HeaderButtonType="TextButton"
DataField="CustomerID" UniqueName="CustomerID">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="ContactName" HeaderText="Contact
Name" HeaderButtonType="TextButton"
DataField="ContactName" UniqueName="ContactName">
</telerik:GridBoundColumn>
<telerik:GridBoundColumn SortExpression="CompanyName" HeaderText="Company"
HeaderButtonType="TextButton"
DataField="CompanyName" UniqueName="CompanyName">
</telerik:GridBoundColumn>
<telerik:GridEditCommandColumn UniqueName="EditCommandColumn" />
</Columns>
</MasterTableView>
</telerik:RadGrid>
<asp:AccessDataSource ID="AccessDataSource1" DataFile="~/Grid/Data/Access/Nwind.mdb"
SelectCommand="SELECT * FROM
Customers" runat="server"></asp:AccessDataSource>
<asp:AccessDataSource ID="AccessDataSource2" DataFile="~/Grid/Data/Access/Nwind.mdb"
SelectCommand="SELECT * FROM
Orders Where CustomerID = ?" runat="server">
<SelectParameters>
<asp:Parameter Name="CustomerID" Type="string" />
</SelectParameters>
</asp:AccessDataSource>
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And in the code-behind:
| VB.NET |
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Protected Sub RadGrid1_ItemCommand(ByVal source As Object, ByVal e As
Telerik.Web.UI.GridCommandEventArgs) Handles RadGrid1.ItemCommand
If (e.CommandName = RadGrid.UpdateCommandName AndAlso e.Item.OwnerTableView.DataSourceID = "AccessDataSource2") Then
Dim OrderID As
String = e.Item.OwnerTableView.Items(e.Item.ItemIndex)( "OrderID").Text
RadGrid1.Controls.Add( New LiteralControl("Updated item primary key value is: " & OrderID & "<br/>"))
Dim parentItem As
GridDataItem = e.Item.OwnerTableView.ParentItem
If (Not parentItem
Is Nothing) Then
RadGrid1.Controls.Add( New
LiteralControl("Parent item primary field value is: " &
CType(parentItem.OwnerTableView.DataKeyValues(parentItem.ItemIndex)( "CustomerID"), String)))
End If
End If
If (e.CommandName = RadGrid.InitInsertCommandName Or e.CommandName = RadGrid.PerformInsertCommandName) Then
If (e.Item.OwnerTableView.DataSourceID =
"AccessDataSource2") Then
Dim parentItem =
CType(e.Item.OwnerTableView.ParentItem, GridDataItem)
If (Not parentItem Is Nothing) Then
RadGrid1.Controls.Add( New LiteralControl("Parent item primary field value is: " &
CType(parentItem.OwnerTableView.DataKeyValues(parentItem.ItemIndex)( "CustomerID"), String)))
End If
End If
End If
End Sub
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| C# |
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protected void RadGrid1_ItemCommand(object
source, Telerik.Web.UI.GridCommandEventArgs e)
{
if (e.CommandName == RadGrid.UpdateCommandName
&& e.Item.OwnerTableView.DataSourceID == "AccessDataSource2")
{
string OrderID =
e.Item.OwnerTableView.Items[e.Item.ItemIndex][ "OrderID"].Text;
RadGrid1.Controls.Add( new LiteralControl("Updated item primary key value is: " + OrderID + "<br/>"));
GridDataItem parentItem = e.Item.OwnerTableView.ParentItem;
if (parentItem !=
null)
{
RadGrid1.Controls.Add( new
LiteralControl("Parent item primary field value is: " +
( string)(parentItem.OwnerTableView.DataKeyValues[parentItem.ItemIndex][ "CustomerID"])));
}
}
if (e.CommandName == RadGrid.InitInsertCommandName ||
e.CommandName == RadGrid.PerformInsertCommandName)
{
if (e.Item.OwnerTableView.DataSourceID == "AccessDataSource2")
{
GridDataItem parentItem =
(GridDataItem)(e.Item.OwnerTableView.ParentItem);
if (parentItem != null)
{
RadGrid1.Controls.Add(
new LiteralControl("Parent item primary field value is: " +
( string)(parentItem.OwnerTableView.DataKeyValues[parentItem.ItemIndex][ "CustomerID"])));
}
}
}
}
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