Merge excel files into a new excel file based on filename - excel

Question

I have a folder containing about 500-600 excel files from a script I have made where the file names end up like this
101a12345.xlsx
101a67899.xlsx
102a12345.xlsx
102a78999.xlsx
The file names follow that patern, 101a, 102a etc. What i want to do is merge those based on that paternt into 1 excel file. Therefore, the 101a12345.xlsx and 101a67899.xlsx should merge into an 101aMaster.xlsx. All excel files are single sheet.
I have found a sample code here which i am trying to implement: How to merge multiple workbooks into one based on workbooks names
Taken from the link above:
Sub test(sourceFolder As String, destinationFolder As String)
Const TO_DELETE_SHEET_NAME As String = "toBeDeleted"
'------------------------------------------------------------------
Dim settingSheetsNumber As Integer
Dim settingDisplayAlerts As Boolean
Dim dict As Object
Dim wkbSource As Excel.Workbook
Dim wks As Excel.Worksheet
Dim filepath As String
Dim code As String * 4
Dim wkbDestination As Excel.Workbook
Dim varKey As Variant
'------------------------------------------------------------------
'Change [SheetsInNewWorkbook] setting of Excel.Application object to
'create new workbooks with a single sheet only.
With Excel.Application
settingDisplayAlerts = .DisplayAlerts
settingSheetsNumber = .SheetsInNewWorkbook
.SheetsInNewWorkbook = 1
.DisplayAlerts = False
End With
Set dict = VBA.CreateObject("Scripting.Dictionary")
filepath = Dir(sourceFolder)
'Loop through each Excel file in folder
Do While filepath <> ""
If VBA.Right$(filepath, 5) = ".xlsx" Then
Set wkbSource = Excel.Workbooks.Open(sourceFolder & filepath)
Set wks = wkbSource.Worksheets(1)
code = VBA.Left$(wkbSource.Name, 4)
'If this code doesn't exist in the dictionary yet, add it.
If Not dict.exists(code) Then
Set wkbDestination = Excel.Workbooks.Add
wkbDestination.Worksheets(1).Name = TO_DELETE_SHEET_NAME
Call dict.Add(code, wkbDestination)
Else
Set wkbDestination = dict.Item(code)
End If
Call wks.Copy(Before:=wkbDestination.Worksheets(1))
wkbDestination.Worksheets(1).Name = VBA.Mid$(filepath, 6)
Call wkbSource.Close(False)
End If
filepath = Dir
Loop
'Save newly created files.
For Each varKey In dict.keys
Set wkbDestination = dict.Item(varKey)
'Remove empty sheet.
Set wks = Nothing
On Error Resume Next
Set wks = wkbDestination.Worksheets(TO_DELETE_SHEET_NAME)
On Error GoTo 0
If Not wks Is Nothing Then wks.Delete
Call wkbDestination.SaveAs(Filename:=destinationFolder & varKey & ".xlsx")
Next varKey
'Restore Excel.Application settings.
With Excel.Application
.DisplayAlerts = settingDisplayAlerts
.SheetsInNewWorkbook = settingSheetsNumber
End With
End Sub
However, this code opens all workbooks and at about 60-70 open excel files i receive an error: Run-time Error '1004' - Method 'Open' of object 'Workbooks' failed.
is there a way to make this code work?
Excel version is pro plus 2016.

Answer 1

Merge Workbooks
It will open the first of each files starting with the unique first four characters, and copy the first worksheet of each next opened file to the first opened file and finally save it as a new file.
There need not be only 2 files (starting with the same four characters) and there can only be one.
Adjust the values in the constants section.
Option Explicit
Sub mergeWorkbooks()
Const sPath As String = "F:\Test\2021\67077087\"
Const sPattern As String = "*.xlsx"
Const dPath As String = "F:\Test\2021\67077087\Destination\"
Const dName As String = "Master.xlsx"
Const KeyLen As Long = 4
Dim PatLen As Long: PatLen = Len(sPattern)
Dim fName As String: fName = Dir(sPath & sPattern)
Dim dict As Object: Set dict = CreateObject("Scripting.Dictionary")
Do While Len(fName) > 0
dict(Left(fName, KeyLen)) = Empty
fName = Dir
Loop
Application.ScreenUpdating = False
On Error Resume Next
MkDir dPath
On Error GoTo 0
Dim wb As Workbook
Dim Key As Variant
Dim wsLen As Long
For Each Key In dict.Keys
Set wb = Nothing
fName = Dir(sPath & Key & sPattern)
Do While Len(fName) > 0
wsLen = Len(fName) - PatLen - KeyLen + 2
If wb Is Nothing Then
Set wb = Workbooks.Open(sPath & fName)
wb.Worksheets(1).Name = Mid(fName, KeyLen, wsLen)
'Debug.Print wb.Name
Else
With Workbooks.Open(sPath & fName)
'Debug.Print .Name
.Worksheets(1).Name = Mid(fName, KeyLen, wsLen)
.Worksheets(1).Copy After:=wb.Sheets(wb.Sheets.Count)
.Close False
End With
End If
fName = Dir
Loop
Application.DisplayAlerts = False
wb.SaveAs dPath & Key & dName ', xlOpenXMLWorkbook
Application.DisplayAlerts = True
wb.Close False
Next Key
Application.ScreenUpdating = True
End Sub
Test for Names
Use the following to print all names in the active workbook to the VBE Immediate window (CTRL+G).
Sub listNames()
Dim nm As Name
For Each nm In ActiveWorkbook.Names
Debug.Print nm.Name
Next nm
End Sub
First, check if the names (if any) are used in some formulas.
Use the following to delete all names in the active workbook.
Sub deleteNames()
Dim nm As Name
For Each nm In ActiveWorkbook.Names
nm.Delete
Next nm
End Sub

Answer 2

Untested but here's one approach where you don't have multiple files open at the same time:
Sub test(sourceFolder As String, destinationFolder As String)
Dim dict As Object, code As String
Dim colFiles As Collection, f, k, wbNew As Workbook, wb As Workbook
Set dict = VBA.CreateObject("Scripting.Dictionary")
'ensure trailing "\"
EnsureSlash sourceFolder
EnsureSlash destinationFolder
'get a collection of all xlsx files in the source folder
Set colFiles = allFiles(sourceFolder, "*.xlsx")
If colFiles.Count = 0 Then Exit Sub 'no files
'organize the files into groups according to first four characters of the filename
For Each f In colFiles
code = Left(f.Name, 4)
If Not dict.exists(code) Then Set dict(code) = New Collection 'need new group?
dict(code).Add f 'add the file to the collection for this code
Next f
'loop over the groups
For Each k In dict
Set colFiles = dict(k) 'the files for this code
Set wbNew = Workbooks.Add(Template:=xlWBATWorksheet) 'one sheet
For Each f In colFiles
With Workbooks.Open(f.Path)
.Worksheets(1).Copy after:=wbNew.Sheets(wbNew.Sheets.Count)
wbNew.Sheets(wbNew.Sheets.Count).Name = Replace(f.Name, ".xlsx", "")
.Close False
End With
Next f
Application.DisplayAlerts = False
wbNew.Sheets(1).Delete 'remove the empty sheet
Application.DisplayAlerts = True
wbNew.SaveAs destinationFolder & k & ".xlsx"
wbNew.Close
Next k
End Sub
'Return all files in `sourceFolder` which match `pattern`
' as a collection of file objects
Function allFiles(sourceFolder As String, pattern As String) As Collection
Dim col As New Collection, f
For Each f In CreateObject("scripting.filesystemobject").getfolder(sourceFolder).Files
If f.Name Like pattern Then col.Add f
Next f
Set allFiles = col
End Function
'Utility - check a path ends in a backslash
' use Application.PathSeparator if needs to be cross-platform
Sub EnsureSlash(ByRef f As String)
If Right(f, 1) <> "\" Then f = f & "\"
End Sub