主题：【问题解决，但是有了新的问题】请问大家：如何找出标记了的客户最近一次拜访日期，请看例子

Dim filter As String = "标记 = true and 日期 <= #" & Date.Today.AddDays(-5) & "#"

Dim count As Integer = DataTables("表A").Compute("count(_Identify)", filter)

msgbox(count)

Tables("表A").Filter = filter

Dim dt As DataTable = DataTables("表A")

Dim names As List(Of String) = dt.GetUniqueValues("姓名 is not null", "姓名")

Dim count As Integer = 0

For Each name As String In names

    Dim fdr As DataRow = dt.Find("姓名 = '" & name & "'", "日期 desc")

    If fdr IsNot Nothing AndAlso fdr("日期") <= Date.Today.AddDays(-5) Then

        count += 1

    End If

Next

msgbox(count)

Dim dt As DataTable = DataTables("表A")

Dim names As List(Of String) = dt.GetUniqueValues("姓名 is not null", "姓名")

Dim count As Integer = 0

Dim idxs As String = ""

For Each name As String In names

    Dim fdr As DataRow = dt.Find("姓名 = '" & name & "'", "日期 desc")

    If fdr IsNot Nothing AndAlso fdr("日期") <= Date.Today.AddDays(-5) Then

        count += 1

        idxs += fdr("_identify") & ","

    End If

Next

msgbox(count)

If count > 0 Then

    Tables(dt.Name).Filter = "_identify in (" & idxs.Trim(",") & ")"

End If