主题：如何设计“单项平均”公式？

Dim Names As List(Of String)

Names = DataTables("学生评分表").GetUniqueValues("","教师姓名")

For Each Name As String In Names

   Dim Sum As Double = DataTables("学生评分表").Compute("Sum(你认为老师的教学态度_合计)","[教师姓名] = '" & Name & "'")

   Dim Count As Integer = DataTables("学生评分表").Compute("Count(教师姓名)","[教师姓名] = '" & Name & "'")

   Dim Drs As List(Of DataRow) = DataTables("学生评分表").Select("[教师姓名] = '" & Name & "'")

   Dim Avg As Double = Math.Round(Sum / Count,3)

   For Each dr As DataRow In Drs

       dr("你认为老师的教学态度_单项平均") = avg

   Next

  Sum = DataTables("学生评分表").Compute("Sum(你认为老师创设的课堂情景_合计)","[教师姓名] = '" & Name & "'")

  Count = DataTables("学生评分表").Compute("Count(教师姓名)","[教师姓名] = '" & Name & "'")

  Drs = DataTables("学生评分表").Select("[教师姓名] = '" & Name & "'")

  Avg = Math.Round(Sum / Count,3)

  For Each dr As DataRow In Drs

      dr("你认为老师创设的课堂情景_单项平均") = avg

  Next

Next

不过这样的设计始终是有问题的，应该有单独的统计表，否则计算的耗时可以忍受，但是存盘就慢多了，可能要几分钟，因为foxtable只保存修改过的行，所以日常的应用存盘效率高过易表，但是你这样设计的话，等于每次计算后，11万行全部被修改过，存盘的速度可想而知。