Declarative Definition

When defining RadGrid declaratively, the structure of the objects in the ASPX form mirrors the structure of the tables in the RadGrid control. Inside the RadGrid declaration, the MasterTableView declaration is nested. This corresponds to a GridTableView object for the top-level table in the grid. If the grid has a hierarchical structure, a DetailTables node is added to hold the detail tables for any table view that has children. Inside the DetailTables node, add the declarations for the GridTableView objects that represent each detail table.

The following example shows the declaration of a three-tier hierarchical grid:

Scenario - RadGrid Hierarchy with 3 levels

<telerik:RadGrid ID="RadGrid1" runat="server" Skin="Bootstrap" RenderMode="Lightweight"
    OnDetailTableDataBind="RadGrid1_DetailTableDataBind"
    OnNeedDataSource="RadGrid1_NeedDataSource">
    <MasterTableView Name="Customers" DataKeyNames="CustomerID" Caption="Customers Table">
        <DetailTables>
            <telerik:GridTableView Name="Orders" DataKeyNames="OrderID" Caption="Orders Table">
                <DetailTables>
                    <telerik:GridTableView Name="OrderDetails" DataKeyNames="ProductID" Caption="Order Details Table">
                    </telerik:GridTableView>
                </DetailTables>
            </telerik:GridTableView>
        </DetailTables>
    </MasterTableView>
</telerik:RadGrid>

protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
{
    if (!e.IsFromDetailTable)
        (sender as RadGrid).DataSource = Enumerable.Range(1, 3).Select(x => new DbRecord()
        {
            ID = x,
            Description = string.Format("Table {0}, Item {1}", (sender as RadGrid).MasterTableView.Name, x)
        });
}
protected void RadGrid1_DetailTableDataBind(object sender, GridDetailTableDataBindEventArgs e)
{
    e.DetailTableView.DataSource = Enumerable.Range(1, 3).Select(x => new DbRecord()
    {
        ID = x,
        Description = string.Format("Table {0}, Item {1}", e.DetailTableView.Name, x)
    });
}
public class DbRecord
{
    public int ID { get; set; }
    public string Description { get; set; }
}

Protected Sub RadGrid1_NeedDataSource(ByVal sender As Object, ByVal e As GridNeedDataSourceEventArgs)
    If Not e.IsFromDetailTable Then (TryCast(sender, RadGrid)).DataSource = Enumerable.Range(1, 3).[Select](Function(x) New DbRecord() With {
        Key .ID = x,
        Key .Description = String.Format("Table {0}, Item {1}", (TryCast(sender, RadGrid)).MasterTableView.Name, x)
    })
End Sub

Protected Sub RadGrid1_DetailTableDataBind(ByVal sender As Object, ByVal e As GridDetailTableDataBindEventArgs)
    e.DetailTableView.DataSource = Enumerable.Range(1, 3).[Select](Function(x) New DbRecord() With {
        Key .ID = x,
        Key .Description = String.Format("Table {0}, Item {1}", e.DetailTableView.Name, x)
    })
End Sub

Public Class DbRecord
    Public Property ID As Integer
    Public Property Description As String
End Class

<telerik:RadGrid RenderMode="Lightweight" ID="RadGrid1" runat="server" DataSourceID="AccessDataSource1">
  <MasterTableView DataKeyNames="CustomerID" DataSourceID="AccessDataSource1">
    <DetailTables>
      <telerik:GridTableView runat="server" DataKeyNames="OrderID" DataSourceID="AccessDataSource2">
        <ParentTableRelation>
          <telerik:GridRelationFields DetailKeyField="CustomerID" MasterKeyField="CustomerID" />
        </ParentTableRelation>
        <DetailTables>
          <telerik:GridTableView runat="server" DataSourceID="AccessDataSource3">
            <ParentTableRelation>
              <telerik:GridRelationFields DetailKeyField="OrderID" MasterKeyField="OrderID" />
            </ParentTableRelation>
          </telerik:GridTableView>
        </DetailTables>
      </telerik:GridTableView>
    </DetailTables>
  </MasterTableView></telerik:RadGrid>
<asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/App_Data/Nwind.mdb"
  SelectCommand="SELECT * FROM [Customers]"></asp:AccessDataSource>
<asp:AccessDataSource ID="AccessDataSource2" runat="server" DataFile="~/App_Data/Nwind.mdb"
  SelectCommand="SELECT * FROM [Orders] WHERE ([CustomerID] = ?)">
  <SelectParameters>
    <asp:Parameter Name="CustomerID" Type="String" />
  </SelectParameters>
</asp:AccessDataSource>
<asp:AccessDataSource ID="AccessDataSource3" runat="server" DataFile="~/App_Data/Nwind.mdb"
  SelectCommand="SELECT * FROM [Order Details] WHERE ([OrderID] = ?)">
  <SelectParameters>
    <asp:Parameter Name="OrderID" Type="Int32" />
  </SelectParameters>
</asp:AccessDataSource>