主题：状态更新

方法一：

DataTables("ISO_Index").loadfilter = ""
DataTables("ISO_Index").loadTop = "100 percent"
DataTables("ISO_Index").load
msgbox(2)
For Each u As String In DataTables("ISO_Index").GetValues("Document_No")
    If DataTables("ISO_Index").Compute("Count([_Identify])","Document_No = '" & u & "'") > 1 Then
        Dim md As Date = DataTables("ISO_Index").Compute("Max(RecieveDate)","Document_No = '" & u & "'")
        Dim dss As List(Of DataRow)
        dss = DataTables("ISO_Index").Select("[Document_No] = '" & u & "'")
        For i As Integer = 0 To dss.Count-1
            If dss(i)("RecieveDate") < md Then
                dss(i)("REV_Status") = "Updated"
            Else
                dss(i)("REV_Status")  = "New"
            End If
        Next
    End If
Next

方法二：

可以先生成分组统计表，得到每个 No 对应的最大值，然后用 SQLReplaceFor 直接更新 http://www.foxtable.com/webhelp/scr/2898.htm

方法三：上传具体实例测试。

Dim pdr As DataRow = Nothing
For Each dr As DataRow In dt.Select("", "Document_No, RecieveDate desc")
    If pdr Is Nothing OrElse pdr("Document_No") <> dr("Document_No") Then
        dr("REV_Status")  = "New"
        pdr = dr
    Else
        If dr("RecieveDate")<pdr("RecieveDate") Then
            dr("REV_Status") = "Updated"
        Else
            dr("REV_Status") = "new"
        End If
    End If
Next