e.Form.Controls("Label1").text="请稍等,正在计时..."

dim timestart,timeend as date

timestart=date.now

CurrentTable.Redraw = False \'暂停刷新表

For Each c as Datacol in DataTables("学生各科成绩表").Datacols \'遍历学生各科成绩表中的所有列

  if c.name = "语文" Or c.name = "数学" or c.name = "英语" or c.name = "化学" or c.name = "物理" or c.name = "总分" Then \'如果等于这些列

    Dim pm As New List(Of String) \'定义一个字符型的集合

    Dim pmc As Integer \'定义一个数值型变量

    pm = CurrentTable.DataTable.GetUniqueValues("","班级") \'从学生各科成绩表中提取不重复的班级保存到集合中

    For i As Integer = 0 To pm.Count -1  \'遍历班级集合

        CurrentTable.Filter= "[班级] = \'" & pm(i) & "\'" \'\'筛选

        Currenttable.sort = c.name & " DESC" \'按降序排序

        pmc = 0 \'赋于变量初始值

        For n As integer = 0 to Currenttable.rows.Count -1 \'遍历学生各科成绩表中的所有行

            pmc = pmc +1

            If n > 0 AndAlso Currenttable.rows(n)(c.name) = Currenttable.rows(n-1)(c.name) Then \'如果不是第一行且计算行等于上一行的值

                CurrentTable.Rows(n)(c.name & "班级排名") = CurrentTable.Rows(n-1)(c.name & "班级排名") \'就赋于上一行的值

            Else

                CurrentTable.Rows(n)(c.name & "班级排名") = pmc \'当前计算行的行号加 1(变量pmc的步长值为1)

            End If

        Next

    Next

  End if

Next

CurrentTable.Filter = "" \'取消筛选

CurrentTable.Redraw = True \'刷新表

Tables("学生各科成绩表").Sort = "总分 DESC" \'排序,对总分列以降序排序

timeend=date.now

e.Form.Controls("Label1").text="耗时" & (timeend-timestart).TotalSeconds & "秒"

Messagebox.Show("统计完毕!")

呵，忘了双精度小数现在也可以筛选了

统计班级各项排名相当慢,是不是把简单问题弄复杂了.看看图

e.Form.Controls("Label1").text="请稍等,正在计时..."

dim timestart,timeend as date

timestart=date.now

Dim pm As List(Of String) = CurrentTable.DataTable.GetUniqueValues("","班级")

Dim pmc As Integer

Dim ColNames() As String = {"数学","英语","化学","物理","总分"}

Dim TotalName As String

CurrentTable.Redraw = False \'刷新表

For Each ColName As string In ColNames

    For i As Integer = 0 To pm.Count -1

        CurrentTable.Filter= "[班级] = \'" & pm(i) & "\'"

        Currenttable.sort = ColName & " DESC"

        pmc = 0

        TotalName = ColName & "班级排名"

        For n As integer = 0 to Currenttable.rows.Count -1

            pmc = pmc +1

            If n > 0 AndAlso Currenttable.rows(n)(TotalName ) = Currenttable.rows(n-1)(TotalName ) Then

                CurrentTable.Rows(n)(TotalName ) = CurrentTable.Rows(n-1)(TotalName )

            Else

                CurrentTable.Rows(n)(TotalName ) = pmc

            End If

        Next

    Next

Next

Tables("学生各科成绩表").Sort = "总分 DESC" \'排序,对总分列以降序排序

CurrentTable.Filter = "" \'取消筛选

CurrentTable.Redraw = True \'刷新表

timeend=date.now

e.Form.Controls("Label1").text="耗时" & (timeend-timestart).TotalSeconds & "秒"

Messagebox.Show("统计完毕!")

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点击浏览该文件:学生成绩统计分析表.rar

以下是引用狐狸爸爸在2008-11-12 8:22:00的发言：
呵呵，我怎么测试才一秒左右啊。
用下面的代码应该好一点。
还有要注意不是所有的列都应该设置成双精度型，排名、班级、学号这样的列应该是整数型。

e.Form.Controls("Label1").text="请稍等,正在计时..."

dim timestart,timeend as date

timestart=date.now

Dim pm As List(Of String) = CurrentTable.DataTable.GetUniqueValues("","班级")

Dim pmc As Integer

Dim ColNames() As String = {"数学","英语","化学","物理","总分"}

Dim TotalName As String

CurrentTable.Redraw = False \'刷新表

For Each ColName As string In ColNames

    For i As Integer = 0 To pm.Count -1

        CurrentTable.Filter= "[班级] = \'" & pm(i) & "\'"

        Currenttable.sort = ColName & " DESC"

        pmc = 0

        TotalName = ColName & "班级排名"

        For n As integer = 0 to Currenttable.rows.Count -1

            pmc = pmc +1

            If n > 0 AndAlso Currenttable.rows(n)(TotalName ) = Currenttable.rows(n-1)(TotalName ) Then

                CurrentTable.Rows(n)(TotalName ) = CurrentTable.Rows(n-1)(TotalName )

            Else

                CurrentTable.Rows(n)(TotalName ) = pmc

            End If

        Next

    Next

Next

Tables("学生各科成绩表").Sort = "总分 DESC" \'排序,对总分列以降序排序

CurrentTable.Filter = "" \'取消筛选

CurrentTable.Redraw = True \'刷新表

timeend=date.now

e.Form.Controls("Label1").text="耗时" & (timeend-timestart).TotalSeconds & "秒"

Messagebox.Show("统计完毕!")

下载信息  [文件大小：127.3 KB  下载次数：1]

点击浏览该文件:学生成绩统计分析表.rar

[此贴子已经被作者于2008-11-12 8:25:52编辑过]

一个字 好