How to see who is using my Access database over the network?

Question

I actually have 2 questions:

1. How might I see who is using my Access database?

• E.g: There is someone with an Access database opened and it created

Answer 1

Update: Rather than reading and parsing the .ldb/.lacdb file, a better approach would be to use the "User Roster" feature of the Access OLEDB provider as described in the Knowledge Base article

https://support.microsoft.com/en-us/kb/285822

and in the other SO question

Get contents of laccdb file through VBA

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Original answer:

I put together the following a while ago. It looked promising but then I discovered that computers are not immediately removed from the lock file when they disconnect. Instead, Jet/ACE seems to (internally) mark them as inactive: If ComputerA disconnects and then ComputerB connects, ComputerB overwrites ComputerA's entry in the lock file.

Still, it does provide a list of sorts. I'm posting it here in case somebody can offer some suggestions for refinement.

I created two tables in my back-end database:

Table: [CurrentConnections]
computerName  Text(255), Primary Key

Table: [ConnectionLog]
computerName  Text(255), Primary Key
userName      Text(255)

A VBA Module in my back-end database contained the following code to read (a copy of) the lock file and update the [CurrentConnections] table:

Public Sub GetCurrentlyConnectedMachines()
    Dim cdb As DAO.Database, rst As DAO.Recordset
    Dim fso As Object  '' FileSystemObject
    Dim lck As Object  '' ADODB.Stream
    Dim lockFileSpec As String, lockFileExt As String, tempFileSpec As String
    Dim buffer() As Byte

    Set cdb = CurrentDb
    cdb.Execute "DELETE FROM CurrentConnections", dbFailOnError
    Set rst = cdb.OpenRecordset("SELECT computerName FROM CurrentConnections", dbOpenDynaset)

    lockFileSpec = Application.CurrentDb.Name
    If Right(lockFileSpec, 6) = ".accdb" Then
        lockFileExt = ".laccdb"
    Else
        lockFileExt = ".ldb"
    End If
    lockFileSpec = Left(lockFileSpec, InStrRev(lockFileSpec, ".", -1, vbBinaryCompare) - 1) & lockFileExt

    '' ADODB.Stream cannot open the lock file in-place, so copy it to %TEMP%
    Set fso = CreateObject("Scripting.FileSystemObject")  '' New FileSystemObject
    tempFileSpec = fso.GetSpecialFolder(2) & "\" & fso.GetTempName
    fso.CopyFile lockFileSpec, tempFileSpec, True

    Set lck = CreateObject("ADODB.Stream")  '' New ADODB.Stream
    lck.Type = 1  '' adTypeBinary
    lck.Open
    lck.LoadFromFile tempFileSpec
    Do While Not lck.EOS
        buffer = lck.Read(32)
        rst.AddNew
        rst!computerName = DecodeSZ(buffer)
        rst.Update
        buffer = lck.Read(32)  '' skip accessUserId, (almost) always "Admin"
    Loop
    lck.Close
    Set lck = Nothing
    rst.Close
    Set rst = Nothing
    Set cdb = Nothing
    fso.DeleteFile tempFileSpec
    Set fso = Nothing
End Sub

Private Function DecodeSZ(buf() As Byte) As String
    Dim b As Variant, rt As String
    rt = ""
    For Each b In buf
        If b = 0 Then
            Exit For  '' null terminates the string
        End If
        rt = rt & Chr(b)
    Next
    DecodeSZ = rt
End Function

The following code in the Main_Menu form of the front-end database updated the [ConnectionLog] table

Private Sub Form_Load()
    Dim cdb As DAO.Database, rst As DAO.Recordset
    Dim wshNet As Object  '' WshNetwork

    Set wshNet = CreateObject("Wscript.Network")
    Set cdb = CurrentDb
    Set rst = cdb.OpenRecordset("SELECT * FROM ConnectionLog", dbOpenDynaset)
    rst.FindFirst "ComputerName=""" & wshNet.computerName & """"
    If rst.NoMatch Then
        rst.AddNew
        rst!computerName = wshNet.computerName
    Else
        rst.Edit
    End If
    rst!userName = wshNet.userName
    rst.Update
    Set wshNet = Nothing
End Sub

Finally, the following form in the back-end database listed [its best guess at] the current connections

It is a "continuous forms" form whose Record Source is

SELECT CurrentConnections.computerName, ConnectionLog.userName 
FROM CurrentConnections LEFT JOIN ConnectionLog 
    ON CurrentConnections.computerName = ConnectionLog.computerName 
ORDER BY ConnectionLog.userName; 

and the code-behind is simply

Private Sub Form_Load()
    UpdateFormData
End Sub

Private Sub cmdRefresh_Click()
    UpdateFormData
End Sub

Private Sub UpdateFormData()
    GetCurrentlyConnectedMachines
    Me.Requery
End Sub

Answer 2

RE: How might I see who is using my Access database? •E.g: There is someone with an Access database opened and it created the .ldb file, I would like to see a list of who opened that database (it could be more than one person).

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Just happened across this while looking for something else, and I thought I might share what I do for this. Note that this assumes that the host computer (the computer on which the database file resides) uses file sharing to provide access to the file.

You will need to be on the host computer, or have authority to connect to that machine.

click Start right-click My Computer and select Manage

if you're not on the host computer, right-click 'Computer Management' and enter the host's name

Expand 'Shared Folders' and click on 'Open Files' At the right is the list of currently open files with the username for each current user

Answer 3

Easy. Open the .ldb file in notepad (or any text editor) and you can see the machine names.

Answer 4

I agree with Gord's Original answer. I used this code on my database, it seems that there is a way around computers not being taken out of CurrentConnections upon exit of the DB.

I placed this on my main menu form because it is always open until the user exits. I used the unload event on my form to get this to work, and it works awesome! Here is my code

p.s. Ignore SetWarnings I just have that on so the user doesn't have to click through prompts.

Private Sub Form_Unload(Cancel As Integer)
Dim wshNet As Object
Dim deleteSQL As String

Set wshNet = CreateObject("WScript.Network")
        DoCmd.SetWarnings False
        deleteSQL = "DELETE tblCurrentConnections.* " & _
        "FROM tblCurrentConnections WHERE[computerName] = '" & wshNet.computerName & "';"
                DoCmd.RunSQL deleteSQL
        DoCmd.SetWarnings True
End Sub