这里的慢应该大部分时间花在了加载和保存上面,反正都要加载,不如一次性加载出来再计算,我测试也就几十秒
Dim dt As DataTable = DataTables("成绩")
dt.load()
Dim Arys As List(Of String()) = dt.GetValues("考试名称|学校代码|年级代码")
For Each Ary As String() In Arys
Dim drs As List(Of DataRow) = dt.Select("[考试名称] = '" & ary(0) & "'And [学校代码] = '" & ary(1) & "'and [年级代码] ='" & ary(2) & "'", "折总 DESC")
For n As Integer = 0 To drs.Count - 1 '遍历所有行
If n > 0 AndAlso drs(n)("折总") = drs(n-1)("折总") Then '如果总分和上一行相同
drs(n)("校序") = drs(n-1)("校序") '则排名等于上一行
Else
drs(n)("校序") = n + 1 '设置排名
End If
Next
Next
Dim Arys1 As List(Of String()) = dt.GetValues("考试名称|学校代码|年级代码|班级")
For Each Ary1 As String() In Arys1
Dim drs As List(Of DataRow) = dt.Select("[考试名称] = '" & ary1(0) & "'And [学校代码] = '" & ary1(1) & "'and [年级代码] ='" & ary1(2) & "'And [班级] = '" & ary1(3) & "'", "折总 DESC")
For m As Integer = 0 To drs.Count - 1 '遍历所有行
If m > 0 AndAlso drs(m)("折总") = drs(m-1)("折总") Then '如果总分和上一行相同
drs(m)("班序") = drs(m-1)("班序") '则排名等于上一行
Else
drs(m)("班序") = m + 1 '设置排名
End If
Next
Next
dt.save()