How To Automate a Secured Access Database Using Visual Basic (192919)

MORE INFORMATION

There are two ways to secure a Microsoft Access database:

• One is to furnish individual MDBs with passwords. Although in DAO, you can use the OpenDatabase method to open such a database without getting a password prompt, there is no method to do so in Access prior to Access 2002. The Application.OpenCurrentDatabase method of Access2002 includes and optional parameter to specify the database password.
  
  
• The second method is to provide a series of usernames and passwords to secure Access itself. The username and password prompt can be avoided in this case by using the Shell command and the GetObject method.

The main problem with using the Shell command to open a secured Access database is that Access does not register itself in the running object table until it has lost focus once. This means that until Access loses focus, it cannot be found with a call to GetObject and automated. The following Visual Basic code demonstrates how to launch a secured Access database and get the running instance of Access so it can be automated.

Step by Step Example

1. Open a new Standard EXE project in Visual Basic. Form1 is created by default.
2. Choose References from the Project menu, check Microsoft Access 8.0 Object Library, and then click OK. For Access 2000, check Microsoft Access 9.0 Object Library. For Access 2002, check Microsoft Access 10.0 Object Library.
3. Add a CommandButton to Form1 and put the following code into Form1's code window:

         Private Declare Sub Sleep Lib "Kernel32" (ByVal dwMS As Long)
   
         Private Sub Command1_Click()
         Dim accObj As Access.application, Msg As String
         Dim application As String, dbs As String, workgroup As String
         Dim user As String, password As String, cTries As Integer
         Dim x
   
         ' This is the default location of Access
         application = "C:\Program Files\Microsoft Office\Office\MSACCESS.EXE"
         ' Use the path and name of a secured MDB on your system
         dbs = "C:\TestDatabase.mdb"
         ' This is the default workgroup
         workgroup = "C:\Windows\System\System.mdw "
         user = "Admin"           ' Use a valid username
         password = "Mypassword"  ' and correct password
    
         x = Shell(application & " " & Chr(34) & dbs & Chr(34) & " /nostartup /user " & user & _
         " /pwd " & password & " /wrkgrp " & Chr(34) & workgroup & Chr(34), vbMinimizedFocus)
   
         On Error GoTo WAITFORACCESS
         Set accObj = GetObject(, "Access.Application")
   
         ' Turn off error handling
         On Error GoTo 0
   
         ' You can now use the accObj reference to automate Access
   
         Msg = "Access is now open. You can click on Microsoft Access "
         Msg = Msg & "in the Taskbar to see that your database is open."
         Msg = Msg & vbCrLf & vbCrLf & "When ready, click OK to close."
         MsgBox Msg, , "Success!"
   
         accObj.CloseCurrentDatabase
         accObj.Quit
   
         Set accObj = Nothing
         MsgBox "All Done!", vbMsgBoxSetForeground
   
         Exit Sub
   
         WAITFORACCESS:               ' <--- This line must be left-aligned.
         ' Access isn't registered in the Running Object Table yet, so call
         ' SetFocus to take focus from Access, wait half a second, and try
         ' again. If you try five times and fail, then something has probably
         ' gone wrong, so warn the user and exit.
         SetFocus
         If cTries < 5 Then
            cTries = cTries + 1
            Sleep 500 ' wait 1/2 seconds
            Resume
         Else
            MsgBox "Access is taking too long. Process ended.", _
               vbMsgBoxSetForeground
         End If
         End Sub
   					

4. Run the project and click on Command1. Your secured MDB will open without prompting you, and a message box will pause the code so that you can verify that your database is actually open. You can then click OK to dismiss the message box and close Access.