Merging Many Workbooks

Joy ran into a problem merging quite a few workbooks together. The majority of the workbooks-about 200 of them, all in a single folder-each contain a single worksheet, but some contain more. The worksheets forming each of these workbooks needs to be added to a single workbook.

The easiest way to do merges of this magnitude-particularly if you have to do it often-is with a macro. The following macro displays a dialog box asking you to select the files to merge. (You can select multiple workbooks by holding down the Ctrl key as you click each one.) It loops thru the list you select, opening each one and moving all its worksheets to the end of the workbook with the code.

Sub CombineWorkbooks()
    Dim FilesToOpen
    Dim x As Integer

    On Error GoTo ErrHandler
    Application.ScreenUpdating = False

    FilesToOpen = Application.GetOpenFilename _
      (FileFilter:="Microsoft Excel Files (*.xls?), *.xls?", _
      MultiSelect:=True, Title:="Files to Merge")

    If TypeName(FilesToOpen) = "Boolean" Then
        MsgBox "No Files were selected"
        GoTo ExitHandler
    End If

    x = 1
    While x <= UBound(FilesToOpen)
        Workbooks.Open FileName:=FilesToOpen(x)
        Sheets().Move After:=ThisWorkbook.Sheets _
          (ThisWorkbook.Sheets.Count)
        x = x + 1
    Wend

ExitHandler:
    Application.ScreenUpdating = True
    Exit Sub

ErrHandler:
    MsgBox Err.Description
    Resume ExitHandler
End Sub

In the process of adding the worksheets to the end of the workbook, Excel will automatically append a (2), (3), etc. when duplicates worksheet names are detected. Any formulas in the book referring to other sheets will also be updated to reflect the new names.