Dim dr As New Infragistics.Web.UI.DataSourceControls.DataRelation() ' Specify the parent view in the relation dr.ParentDataViewID = "SqlDataSource_View1" ' Specify the composite key using two columns dr.ParentColumns = New String() {"FirstName", "LastName"} ' Specify the child view in the relation dr.ChildDataViewID = "SqlDataSource_View2" 'Specify the composite key in the child data source dr.ChildColumns = New String() {"FirstName", "LastName"} ' Add the relation to WebHierarchicalDataSource Me.WebHierarchicalDataSource1.DataRelations.Add(dr)