How to speed up vba code that delete rows when column Q has blank cells - excel

Question

I have a sheet of almost 100000 rows & column A to Q
I have a code that delete entire rows if column Q has blank cells.
I have tried this code on 4000 rows it is running in 3 minutes but when I take 100000 rows it just processing for hours.
I will be very great full if some help/guide me in speeding up this code.
The code is :
Sub DeleteBlank()
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual
Dim lo As ListObject
set lo = sheets("BOM 6061").ListObjects(1)
Sheets("BOM 6061").Activate
lo.AutoFilter.ShowAllData
lo.range.AutoFilter Field:=17, Criteria1:=""
Application.DisplayAlerts = False
Application.Calculation = xlCalculationAutomatic
lo.DataBodyRange.SpecialCells(xlCellsTypeVisible).Delete
Application.DisplayAlerts = True
lo.AutoFilter.ShowAllData
End Sub

Answer 1

Remove Criteria Rows in an Excel Table Efficiently
In a nutshell, if you don't sort the criteria column, deleting the rows may take 'forever'.
The following will do just that, keeping the initial order of the remaining rows.
Option Explicit
Sub DeleteBlankRows()
Const wsName As String = "BOM 6061"
Const tblIndex As Variant = 1
Const CriteriaColumnNumber As Long = 17
Const Criteria As String = ""
' Reference the table.
Dim wb As Workbook: Set wb = ThisWorkbook ' workbook containing this code
Dim ws As Worksheet: Set ws = wb.Worksheets(wsName)
Dim tbl As ListObject: Set tbl = ws.ListObjects(tblIndex)
Application.ScreenUpdating = False
Application.Calculation = xlCalculationManual
' Remove any filters.
If tbl.ShowAutoFilter Then
If tbl.AutoFilter.FilterMode Then tbl.AutoFilter.ShowAllData
Else
tbl.ShowAutoFilter = True
End If
' Add a helper column and write an ascending integer sequence to it.
Dim lc As ListColumn: Set lc = tbl.ListColumns.Add
lc.DataBodyRange.Value = _
ws.Evaluate("ROW(1:" & lc.DataBodyRange.Rows.Count & ")")
' Sort the criteria column ascending.
With tbl.Sort
.SortFields.Clear
.SortFields.Add2 tbl.ListColumns(CriteriaColumnNumber).Range, _
Order:=xlAscending
.Header = xlYes
.Apply
End With
' AutoFilter.
tbl.Range.AutoFilter Field:=CriteriaColumnNumber, Criteria1:=Criteria
' Reference the filtered (visible) range.
Dim svrg As Range
On Error Resume Next
Set svrg = tbl.DataBodyRange.SpecialCells(xlCellTypeVisible)
On Error GoTo 0
' Remove the filter.
tbl.AutoFilter.ShowAllData
' Delete the referenced filtered (visible) range.
If Not svrg Is Nothing Then svrg.Delete
' Sort the helper column ascending.
With tbl.Sort
.SortFields.Clear
.SortFields.Add2 lc.Range, Order:=xlAscending
.Header = xlYes
.Apply
.SortFields.Clear
End With
' Delete the helper column.
lc.Delete
Application.Calculation = xlCalculationAutomatic
Application.ScreenUpdating = True
' Inform.
MsgBox "Blanks deleted.", vbInformation
End Sub

Answer 2

I would not use an Autofilter on large data sets as they can take quite a bit of time trying to enumerate the available options before actually filtering the data. The AutoFilter.ShowAllData takes just as much time. For my super simple test dataset, which consisted of 26 columns of 1000000 rows, it took 30+ seconds for each to process.
From what I can tell you are filtering the list to show only the blank items and then deleting the blank rows. Since the filtering is what is causing the delay we could just loop through each row looking at a specific column and if it is blank you can just delete it. Below is an example of how to do this.
**Edit: After testing I found this to be much slower than what you would want. Check out the next example below as it is super fast.
Option Explicit
Sub DeleteBlank()
Application.ScreenUpdating = False
Dim calcType As Integer
Dim rowCount, columnNumToCheck, currow, dataStartRow As Long
Dim WkSht As String
Dim lo As ListObject
WkSht = "BOM 6061" 'The name of the worksheet where the table is located.
columnNumToCheck = 17 'The column number to check for blank cells.
calcType = Application.Calculation
Application.Calculation = xlCalculationManual
Set lo = Sheets(WkSht).ListObjects(1)
rowCount = lo.ListRows.Count
dataStartRow = (lo.DataBodyRange.Row - 1)
For currow = rowCount To 1 Step -1
If Sheets(WkSht).Cells((currow + dataStartRow), columnNumToCheck).Value = "" Then
Call DeleteRows(WkSht, (currow + dataStartRow))
End If
Next currow
Application.Calculation = calcType
Application.ScreenUpdating = True
End Sub
Private Sub DeleteRows(sheetNameIn As String, startRow As Long, Optional optionalEndRow As Long)
If IsNull(optionalEndRow) Or optionalEndRow = 0 Then
optionalEndRow = startRow
End If
Worksheets(sheetNameIn).Range(startRow & ":" & optionalEndRow).Delete Shift:=xlUp
End Sub
If you are able to sort your data where the blank cells are all together you could use the below to perform a single delete function remove them all at once. This deleted 70000 rows in a few seconds.
Sub DeleteBlankWithSort()
'Application.ScreenUpdating = False
Dim columnNumToCheck, tableLastRow, lrow As Long
Dim calcType As Integer
Dim WkSht As String
Dim lo As ListObject
WkSht = "BOM 6061" 'The name of the worksheet where the table is located.
columnNumToCheck = 17 'The column number to check for blank cells.
calcType = Application.Calculation
Application.Calculation = xlCalculationManual
Set lo = Sheets(WkSht).ListObjects(1)
tableLastRow = FindLastRow(WkSht, (columnNumToCheck))
With lo.Sort
.SortFields.Clear
.SortFields.Add _
Key:=Range("Table1[[#All],[q]]"), _
SortOn:=xlSortOnValues, _
Order:=xlDescending, _
DataOption:=xlSortNormal
.Header = xlYes
.MatchCase = False
.Orientation = xlTopToBottom
.SortMethod = xlPinYin
.Apply
End With
lrow = FindLastRow(WkSht, (columnNumToCheck), (tableLastRow))
Call DeleteRows(WkSht, (tableLastRow), (lrow + 1))
Application.Calculation = calcType
Application.ScreenUpdating = True
End Sub
Private Sub DeleteRows(sheetNameIn As String, startRow As Long, Optional optionalEndRow As Long)
If IsNull(optionalEndRow) Or optionalEndRow = 0 Then
optionalEndRow = startRow
End If
Worksheets(sheetNameIn).Range(startRow & ":" & optionalEndRow).Delete Shift:=xlUp
End Sub
Private Function FindLastRow(sheetNameIn As String, columnNum As Long, Optional optionalStartRow As Long) As Long
'finds the last row of the column passed in the sheetname passed in
If IsNull(optionalStartRow) Or optionalStartRow = 0 Then
optionalStartRow = 1048576
End If
FindLastRow = Worksheets(sheetNameIn).Range(Cells(optionalStartRow, columnNum).Address).End(xlUp).Row
End Function

Answer 3

I had an simple example of this from a while ago. Advanced filtering is the fastest way to filter in place or to filter and copy in excel/vba. In advanced filtering you usually have your filters listed out in columns/rows and can have as many as you need, use >"" for filtering out blanks on a column, should take no time at all. In my example it might be different as this was used alongside sheetchange to autofilter if anything was added to the filters.
Sub Advanced_Filtering_ModV2()
Dim rc As Long, crc As Long, trc As Long
Dim wb As Workbook, ws As Worksheet
Set wb = ActiveWorkbook: Set ws = wb.Worksheets("sheet1")
ws.Range("AA1").Value = ws.Range("Q1").Value: ws.Range("AA2").Value = ">"""""
On Error Resume Next
ws.ShowAllData: rc = ws.Range("A" & Rows.Count).End(xlUp).Row
ws.Range("A1:V" & rc).AdvancedFilter Action:=xlFilterInPlace, CriteriaRange:=ws.Range("AA1:AA2")
On Error GoTo 0
End Sub