主题：[求助]加载树的年月节点按倒序排列（已解决）

用SQL语句设计的加载树，希望“年月”按倒序排列，代码应该如何修改，请各位老师指教，谢谢！！

窗口的AfterLod事件代码设为：
Dim cmd As New SQLCommand
Dim dt As DataTable
cmd.C  '外部数据源
cmd.CommandText = "SELECT DISTINCT 年月,单位 From {数据汇总}"
dt = cmd.ExecuteReader()
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildDataTree(dt, "","年月", "单位")
trv.Nodes.Insert("加载所有数据",0)

目录树的NodeMouseDoubleClick事件设为：
Dim Filter As String
If e.Node.Text = "加载所有数据" Then
    Filter = ""
Else
    Dim Value() As String
    Value = e.Node.FullPath.Split("\")
    Select Case e.Node.Level
        Case 0
            Filter ="[年月] = '" & Value(0) & "'"
        Case 1
            Filter ="[年月] = '" & Value(0) & "' And [单位] = '" & Value(1) & "'"
    End Select
End If
DataTables("数据汇总").LoadFilter = Filter
DataTables("数据汇总").Load()

谢谢狐爸老师的指教，在“数据汇总”表全部加载的前提下，用最后三条代码，可以实现加载树节点倒序；如何用ExecuteReader方法直接从后台提取完整的年月和单位数据，还请狐爸老师指教，谢谢！！

'Dim cmd As New SQLCommand
'Dim dt As DataTable
'cmd.C  '外部数据源
'cmd.CommandText = "SELECT DISTINCT 年月,单位 From {数据汇总}"
'dt = cmd.ExecuteReader()
Dim trv As WinForm.TreeView = e.Form.Controls("TreeView1")
trv.BuildTree("数据汇总", "年月|单位","","年月 DESC,单位")
trv.Nodes.Insert("加载所有数据",0)