MS Access: how to compact current database in VBA

Question

Pretty simple question, I know.

Answer 1

When the user exits the FE attempt to rename the backend MDB preferably with todays date in the name in yyyy-mm-dd format. Ensure you close all bound forms, including hidden forms, and reports before doing this. If you get an error message, oops, its busy so don't bother. If it is successful then compact it back.

See my Backup, do you trust the users or sysadmins? tips page for more info.

Answer 2

If you have the database with a front end and a back end. You can use the following code on the main form of your front end main navigation form:

Dim sDataFile As String, sDataFileTemp As String, sDataFileBackup As String
Dim s1 As Long, s2 As Long

sDataFile = "C:\MyDataFile.mdb"
sDataFileTemp = "C:\MyDataFileTemp.mdb"
sDataFileBackup = "C:\MyDataFile Backup " & Format(Now, "YYYY-MM-DD HHMMSS") & ".mdb"

DoCmd.Hourglass True

'get file size before compact
Open sDataFile For Binary As #1
s1 = LOF(1)
Close #1

'backup data file
FileCopy sDataFile, sDataFileBackup

'only proceed if data file exists
If Dir(sDataFileBackup vbNormal) <> "" Then

        'compact data file to temp file
        On Error Resume Next
        Kill sDataFileTemp
        On Error GoTo 0
        DBEngine.CompactDatabase sDataFile, sDataFileTemp

        If Dir(sDataFileTemp, vbNormal) <> "" Then
            'delete old data file data file
            Kill sDataFile

            'copy temp file to data file
            FileCopy sDataFileTemp, sDataFile

            'get file size after compact
            Open sDataFile For Binary As #1
            s2 = LOF(1)
            Close #1

            DoCmd.Hourglass False
            MsgBox "Compact complete " & vbCrLf & vbCrLf _
                & "Size before: " & Round(s1 / 1024 / 1024, 2) & "Mb" & vbCrLf _
                & "Size after:    " & Round(s2 / 1024 / 1024, 2) & "Mb", vbInformation
        Else
            DoCmd.Hourglass False
            MsgBox "ERROR: Unable to compact data file"
        End If

Else
        DoCmd.Hourglass False
        MsgBox "ERROR: Unable to backup data file"
End If

DoCmd.Hourglass False

Answer 3

DBEngine.CompactDatabase source, dest

Answer 4

Check out this solution VBA Compact Current Database.

Basically it says this should work

Public Sub CompactDB() 
    CommandBars("Menu Bar").Controls("Tools").Controls ("Database utilities"). _
    Controls("Compact and repair database...").accDoDefaultAction 
End Sub 

Answer 5

Yes it is simple to do.

Sub CompactRepair()
  Dim control As Office.CommandBarControl
  Set control = CommandBars.FindControl( Id:=2071 )
  control.accDoDefaultAction
End Sub

Basically it just finds the "Compact and repair" menuitem and clicks it, programatically.

Answer 6

If you don't wish to use compact on close (eg, because the front-end mdb is a robot program that runs continually), and you don't want to create a separate mdb just for compacting, consider using a cmd file.

I let my robot.mdb check its own size:

FileLen(CurrentDb.Name))

If its size exceeds 1 GB, it creates a cmd file like this ...

Dim f As Integer
Dim Folder As String
Dim Access As String
    'select Access in the correct PF directory (my robot.mdb runs in 32-bit MSAccess, on 32-bit and 64-bit machines)
    If Dir("C:\Program Files (x86)\Microsoft Office\Office\MSACCESS.EXE") > "" Then
        Access = """C:\Program Files (x86)\Microsoft Office\Office\MSACCESS.EXE"""
    Else
        Access = """C:\Program Files\Microsoft Office\Office\MSACCESS.EXE"""
    End If
    Folder = ExtractFileDir(CurrentDb.Name)
    f = FreeFile
    Open Folder & "comrep.cmd" For Output As f
    'wait until robot.mdb closes (ldb file is gone), then compact robot.mdb
    Print #f, ":checkldb1"
    Print #f, "if exist " & Folder & "robot.ldb goto checkldb1"
    Print #f, Access & " " & Folder & "robot.mdb /compact"
    'wait until the robot mdb closes, then start it
    Print #f, ":checkldb2"
    Print #f, "if exist " & Folder & "robot.ldb goto checkldb2"
    Print #f, Access & " " & Folder & "robot.mdb"
    Close f

... launches the cmd file ...

Shell ExtractFileDir(CurrentDb.Name) & "comrep.cmd"

... and shuts down ...

DoCmd.Quit

Next, the cmd file compacts and restarts robot.mdb.