Can I share an MS-Access database application via Dropbox?

Question

I have a small Access application that only 3 or 4 people will ever use, but I want them to be able to use it from different locations. Only one person will use it at a time

Answer 1

This is an enhanced version of Gord Thompsons script which tries to inform the user to help them do the "right thing".

It also deals with exceptional behaviour such as bad internet access (it encourages the user NOT to use it!) and it also deals with the script being terminated by the user once access has been opened)

' This uses a second file extension (.Available or .InUse) to indicate the status of the database file,
' makes a local (not synced) copy inthe temp folder and opens that copy in Access.
' The updated file is copied back to the Dropbox folder so it can be synced.
' A backup fodler and file can be created with a date in the filename if the suer chooses to.
'
' The launcher could be invoked by a shortcut whose target is
'
' CSCRIPT.EXE C:\!AA\OpenFMFtoolDatabase.vbs

' Or to debug (it can open in VS if VS has been setup right with an external tool)
' CSCRIPT.EXE /X C:\!AA\OpenFMFtoolDatabase.vbs






' ----------------------------------------------------------------------------------------
' ----------------------------------------------------------------------------------------
' ----------------------------------------------------------------------------------------
' This file is used to open and backup the FMFtool university and Subject database
'
' It can be invoked by a shortcut whose target is  CSCRIPT.EXE C:\!AA\OpenFMFtoolDatabase.vbs
'
' See the tag #DOTHESE below for constants that need to be changed for each specific user


'Option Explicit

' ----------------------------------------------------------------------------------------
' ----------------------------------------------------------------------------------------
' ----------------------------------------------------------------------------------------
' Supporting functions
'
Function LPad(MyString, MakeStringThisLong, PadWithThisChar)

  Dim n: n = 0
  If MakeStringThisLong > Len(MyString) Then n = MakeStringThisLong - Len(MyString)
  LPad = String(n, PadWithThisChar) & MyString

End Function

Function BuildDateForFile()

    Dim TheMonth, TheDay

    TheMonth = LPad(Month(Date), 2, "0")
    TheDay = LPad(Day(Date), 2, "0")

    BuildDateForFile = DatePart("yyyy", Now) & TheMonth & TheDay & "_"

End Function


' ----------------------------------------------------------------------------------------
' ----------------------------------------------------------------------------------------
' ----------------------------------------------------------------------------------------
' Main Procedure
'
Sub OpenDatabase()

    ' -----------------------------------------------------------------
    ' -----------------------------------------------------------------
    ' USER / MACHINE SPECIFIC #DOTHESE

    Const SupportEmail = "mr@harveyfrench.co.uk"
    ' This script may prompt the user to contact support using this email address.

    Const DropboxFolder = "C:\!AA\DropBox\"
    ' A typical value is "C:\Users\Gord\Dropbox\dbStorage\"   Note that it must END WITH a backslash
    ' It is set to the name of the LOCAL folder (ie a folder on the PC running this script) which is synced with dropbox
    ' (or any internet based file sharing system like Dropbox, Onedrive, GDrive, etc)

    Const DatabaseCalled = "University and Subject Database"
    ' The name of the database file without the file extension (ie no .accdb)

    Const DatabaseExtension = ".accdb"
    ' The file extension (eg .accdb)




    ' -----------------------------------------------------------------
    ' -----------------------------------------------------------------
    ' General constants
    Const TemporaryFolder = 2
    Const TAGForINUSE = ".InUse"
    Const TAGForAVAILABLE = ".Available"
    Const TAGForOldLocalFile = ".OldFile"


    Dim WshShell, f, AccessPath, WorkingFolder, DatabaseName
    Dim FileNameWhenInUse, FileNameWhenAvailable
    Dim DropBoxInUse, DropBoxAvailable
    Dim DropboxBackupFolder, DropboxBackupFileName, DropboxDONOTBackupFileName
    Dim LocalFile, OldLocalFile
    Dim blnOpenLocalFile





    ' -----------------------------------------------------------------
    ' Use these lines when delivering the code
    Dim fso
    Set fso = CreateObject("Scripting.FileSystemObject")

    ' -----------------------------------------------------------------
    ' Use may use these lines when writing the code
    'Dim fso As Scripting.FileSystemObject
    'Set fso = New Scripting.FileSystemObject




    ' -----------------------------------------------------------------
    ' About files and folders

    DatabaseName = DatabaseCalled & DatabaseExtension

    FileNameWhenInUse = DatabaseName & TAGForINUSE
    FileNameWhenAvailable = DatabaseName & TAGForAVAILABLE

    DropBoxInUse = DropboxFolder & FileNameWhenInUse
    DropBoxAvailable = DropboxFolder & FileNameWhenAvailable

    DropboxBackupFolder = DropboxFolder & "Backups"

    WorkingFolder = fso.GetSpecialFolder(TemporaryFolder) & "\"

    ' eg often: C:\Users\Harvey\AppData\Local\Temp\

    LocalFile = WorkingFolder & DatabaseName
    OldLocalFile = LocalFile & TAGForOldLocalFile

    blnOpenLocalFile = False

    ' -----------------------------------------------------------------
    ' WARN User
    '
    If vbNo = MsgBox("This will open " & DatabaseName & vbCrLf & _
                     vbCrLf & _
                     "DO YOU HAVE ACCESS TO THE WEB?" & vbCrLf & _
                     vbCrLf & _
                     "Do not click YES unless you are sure you do as the web is needed to prevent other people from opening the above file while you have it open.  " & vbCrLf & _
                     vbCrLf & _
                     "NOTE 1: It is OK to loose web access once the file is opened - but others will not be able to use it again until you have web access (and have closed the file)." & vbCrLf & _
                     vbCrLf & _
                     "NOTE 2: If you click YES and you do not have web accesss, either you or someone else WILL LOOSE ALL changes made to the file!)", vbYesNo) Then
        Exit Sub
    End If


    ' ---------------------------------------------------------------------------------
    ' ---------------------------------------------------------------------------------
    '
    ' Main processing -
    ' The file is only opened if it is available (ie not in use by another person).
    ' It can also be opened if it is determined that the file was not copied back to the dropbox folder
    ' but was "accidentally" left in the temp folder
    ' When it is opened the file is renamed on dropbox to indicate it is unavailable
    '
    If fso.FileExists(DropBoxAvailable) Then

        Set f = fso.GetFile(DropBoxAvailable)

        ' This renames the file on dropbox to be "InUse"
        f.Name = FileNameWhenInUse

        '
        ' Allow dropbox to upload the file ASAP  (if possible, force dropbox to sync here )
        '

        WScript.Echo "Copying database file to temp folder..."
        f.Copy LocalFile
        Set f = Nothing

        blnOpenLocalFile = True

    Else

        If fso.FileExists(DropBoxInUse) Then

           If fso.FileExists(LocalFile) Then

              MsgBox "The database was found locally and will be opened " & vbCrLf & _
              vbCrLf & _
              "(it had already been previoulsy opened by you, but not written back to the dropbox folder (perhaps a process crashed)."

              blnOpenLocalFile = True

           Else

              MsgBox "The database is currently in use by someone else. Try again later."
              blnOpenLocalFile = False

           End If

        Else

            MsgBox "The database could not be found on dropbox " & vbCrLf & _
            vbCrLf & _
            "(Both " & TAGForINUSE & " and " & TAGForAVAILABLE & " versions are missing from dropbox!)."


            If fso.FileExists(LocalFile) Then
               MsgBox "A Copy of the file exists locally on your computer.  " & vbCrLf & _
               vbCrLf & _
               "(The file will be opened and written back to dropbox as usual BUT - " & vbCrLf & _
               "please email " & SupportEmail & " as this situation should not be arising!)."

               blnOpenLocalFile = True

            Else

                If fso.FileExists(OldLocalFile) Then

                   MsgBox "A backup copy of the local file exists (know as the OldLocalFile)" & vbCrLf & _
                   vbCrLf & "Email support on " & SupportEmail & vbCrLf & _
                   "to find out what to do (as this is a really wierd situation)."

                Else

                   MsgBox "A backup copy of the local file DOES NOT EXIST " & vbCrLf & _
                   vbCrLf & "Email support on " & SupportEmail & vbCrLf & _
                   "..but being honest you may be in a really bad pickle, but if you've been taking backups you'll be fine!"

                End If

                blnOpenLocalFile = False

            End If

        End If

    End If


    If blnOpenLocalFile Then


        ' ---------------------------------------------------------------------------------
        ' Take a daily backup
        '

        If Not fso.FolderExists(DropboxBackupFolder) Then
             WScript.Echo "Creating backup folder."
             fso.CreateFolder DropboxBackupFolder
        End If

        DropboxBackupFileName = DropboxBackupFolder & "\" & BuildDateForFile() & DatabaseName
        DropboxDONOTBackupFileName = DropboxBackupFileName & ".NoBackup"
        DropboxBackupFileName = DropboxBackupFileName & ".Backup"

        If Not (fso.FileExists(DropboxBackupFileName)) And Not (fso.FileExists(DropboxDONOTBackupFileName)) Then

            If vbYes = MsgBox("Do you want to take a daily backup? " & vbCrLf & _
                               vbCrLf & "(click YES if a lot of work has been done since the last backup was taken. " & vbCrLf & _
                               " If in doubt click YES)", vbYesNo) Then

                WScript.Echo "Creating daily backup file."
                fso.CopyFile LocalFile, DropboxBackupFileName

            Else
                ' Create an empty text file to flag no backup is wanted that day
                WScript.Echo "No daily backup file will be created."
                fso.CreateTextFile (DropboxDONOTBackupFileName)

            End If

        End If


        ' ---------------------------------------------------------------------------------
        ' Open the file
        '
        Set WshShell = CreateObject("WScript.Shell")
        AccessPath = WshShell.RegRead("HKEY_CLASSES_ROOT\Access.MDBFile\shell\Open\command\")
        AccessPath = Left(AccessPath, InStr(AccessPath, "MSACCESS.EXE") + 12)

        WScript.Echo "Launching Access and Opening temp database file: " & vbCrLf & LocalFile

        WshShell.Run AccessPath & " """ & LocalFile & """", 1, True

        WScript.Echo "Copying temp database file back to Dropbox folder..."
        fso.CopyFile LocalFile, DropBoxInUse

        Set f = fso.GetFile(DropBoxInUse)
        f.Name = FileNameWhenAvailable
        Set f = Nothing

        ' Make another copy of the file that was copied to the dropbox folder, then delete the original file
        ' (This might help stop a bad catastrophe!)


        WScript.Echo "In Temp Folder: Copying temp database file to be .oldfile"
        fso.CopyFile LocalFile, OldLocalFile

        WScript.Echo "In Temp Folder: Deleting temp database file "
        fso.DeleteFile LocalFile

    End If

    Set fso = Nothing

End Sub

' Do the work!
OpenDatabase