主题：引用异常代码求改

物料计划表，需要引用采购明细表里面的供货单位：

If e.DataCol.Name = "识别号" Then
    Dim nms() As String = {"供货单位"}
    If e.NewValue Is Nothing Then
        For Each nm As String In nms
            e.DataRow(nm) = Nothing
        Next
    Else
        Dim dr As DataRow
        dr = DataTables("采购明细").Find("[识别号] = '" & e.NewValue & "'")
        If dr IsNot Nothing
            For Each nm As String In nms
                e.DataRow(nm) = dr(nm)
            Next
        End If
    End If
End If

采购明细表，需要引用物料计划表的订单号，交期：

If e.DataCol.Name = "识别号" Then
    Dim nms() As String = {"订单号","交期"}
    If e.NewValue Is Nothing Then
        For Each nm As String In nms
            e.DataRow(nm) = Nothing
        Next
    Else
        Dim dr As DataRow
        dr = DataTables("物料计划").Find("[识别号] = '" & e.NewValue & "'")
        If dr IsNot Nothing
            For Each nm As String In nms
                e.DataRow(nm) = dr(nm)
            Next
        End If
    End If
End If

以上二段代码，第二段可以实现，第一段不能实现，求救

不行，我再理下思路吧，看能不能不这么做