用VBA For循环找出重名点数据巨慢
VBA查找一个工作表里某列有重名的单元格、值。用for循环来实现,如果发现重名,背景设为红色。当要比较的数据比较大,如有10000个数据时,速度非常慢(无法忍受的慢)。不知道有没有办法加速。请大虾帮忙。代码如下:
Function checkDuplicate(ByVal wsName As String) As Boolean 'true ---has duplicate point
Dim ws As Worksheet
Dim ixRef, i, j, k As Integer
checkDuplicate = False
If ExistSheet(wsName) = True Then
Set ws = ThisWorkbook.Worksheets(wsName)
ws.Columns.ClearFormats
ixRef = ws.Range("A65535").End(xlUp).Row 'calculate the total xref number
For j = 3 To ixRef
If ws.Cells(j, 1).Interior.ColorIndex = -4142 And (UCase(ws.Cells(j, 1)) = "A" Or UCase(ws.Cells(j, 1)) = "D") Then
k = 0
For i = j + 1 To ixRef
If UCase(ws.Cells(i, 1)) = "A" Or UCase(ws.Cells(i, 1)) = "D" Then
If UCase(ws.Cells(j, 7)) = UCase(ws.Cells(i, 7)) Then
checkDuplicate = True
ws.Cells(i, 1).Interior.ColorIndex = 3
k = k + 1
End If
End If
Next
If k > 0 Then
ws.Cells(j, 1).Interior.ColorIndex = 3
End If
End If
Next
Set ws = Nothing
End If
End Function
[解决办法]
双重循环,耗时与行数是指数关系。
是否可以这样做:把 Excel 表当作 JetEngine 的外部数据库,
1 首先查询数据唯一记录,连同行号存入一个 Access 临时表。
2 然后查询原表中行号 Not In 临时表的所有记录。
[解决办法]
having count(field1) >= 2
[解决办法]
用字典对象进行索引,费时的表格操作可以从 O(n^2) 简化到 O(n)。
'需要添加引用:Microsoft Scripting Runtime
Function checkDuplicate(ByVal wsName As String) As Boolean
Dim ws As Worksheet
Dim dic As Scripting.Dictionary
Dim ixRef As Long
Dim i As Long
Dim j As Long
Dim sValue As String
checkDuplicate = False
If ExistSheet(wsName) = True Then
Set ws = ThisWorkbook.Worksheets(wsName)
ws.Columns.ClearFormats
ixRef = ws.Range("A65535").End(xlUp).Row 'calculate the total xref number
Set dic = New Scripting.Dictionary '保存 {行号,值} 的字典
For j = 3 To ixRef
If (UCase(ws.Cells(j, 1)) = "A" Or UCase(ws.Cells(j, 1)) = "D") Then
sValue = UCase(ws.Cells(j, 7))
If dic.Exists(sValue) Then
'重复
checkDuplicate = True
'设置当前行红色
ws.Cells(j, 1).Interior.ColorIndex = 3
'设置首个重复行红色
i = dic.Item(sValue)
If i > 0 Then
ws.Cells(i, 1).Interior.ColorIndex = 3
'将行号变负数,下次不用再设红色了
dic.Item(sValue) = -i
End If
Else
'不重复,则加入字典
dic.Add sValue, j
End If
End If
Next
Set dic = Nothing
Set ws = Nothing
End If
End Function