主题：两个条件如何求和问题

Dim dt As DataTable = DataTables("订单")

DataTables("销售统计").DataRows.Clear

For Each p As String In dt.GetValues("产品ID")

    For Each x As String In dt.GetValues("客户ID")

        Dim dr As DataRow = DataTables("销售统计").AddNew()

        dr("产品ID") = p

        dr("客户ID") = x

        dr("数量") = dt.Compute("sum(数量)" , "[产品ID]='" & p & "'" And "[客户ID]='" & x & "'")

    Next 

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