主题：统计转移

获取需要统计的年月。获取订单的最大最小年月，获取支出的最大最小年月，得到两者的最大最小年月。

Dim dt_tj As DataTable = DataTables("统计")
Dim dt_dd As DataTable = DataTables("订单")
Dim dt_zc As DataTable = DataTables("支出")
For Each ndr As DataRow In dt_tj.Select("")
    Dim i As Integer = ndr("年份")
    Dim j As Integer = ndr("月份")
    If i > 0 AndAlso j > 0 Then
        Dim d As Date = new Date(i, j, 1)
        Dim filter As String = "订单日期 >= #" & d & "# and 订单日期 < #" & d.AddMonths(1) & "#"
        ndr("订单_数量") = val(dt_dd.compute("sum(数量)", filter))
        ndr("订单_价格") = val(dt_dd.compute("sum(价格)", filter))
        Dim fdr As DataRow = dt_dd.Find(filter, "订单日期 desc")
        If fdr IsNot Nothing Then
            ndr("订单_预留价格") = fdr("预留价格")
        Else
            ndr("订单_预留价格") = 0
        End If
        filter = "支出日期 >= #" & d & "# and 支出日期 < #" & d.AddMonths(1) & "#"
        ndr("支出_数量") = val(dt_zc.compute("sum(次数)", filter))
        ndr("支出_单价") = val(dt_zc.compute("sum(单价)", filter))
        fdr = dt_zc.Find(filter, "支出日期 desc")
        If fdr IsNot Nothing Then
            ndr("支出_预留单价") = fdr("预留单价")
        Else
            ndr("支出_预留单价") = 0
        End If
    Else
        ndr("订单_数量") = 0
        ndr("订单_价格") = 0
        ndr("订单_预留价格") = 0
        ndr("支出_数量") = 0
        ndr("支出_单价") = 0
        ndr("支出_预留单价") = 0
    End If
Next

 既然你统计表已经有年月数据，这段删除掉

Dim minDD As Date = dt_dd.compute("min(订单日期)")
Dim minZC As Date = dt_zc.compute("min(支出日期)")
Dim maxDD As Date = dt_dd.compute("max(订单日期)")
Dim maxZC As Date = dt_zc.compute("max(支出日期)")
Dim minDate As Date = iif(minDD<minZC, minDD, minZC)
Dim maxDate As Date = iif(maxDD>maxZC, maxDD, maxZC)