Workspace Object (DAO)

A Workspace object defines a named session for a user. It contains open databases and provides mechanisms for simultaneous transactions and, in Microsoft Access workspaces, secure workgroup support.

Remarks

A Workspace is a non-persistent object that defines how your application interacts with data by using the Microsoft Access database engine. Use the Workspace object to manage the current session or to start an additional session. In a session, you can open multiple databases or connections, and manage transactions. For example, you can:

• Use the Name, UserName, and Type properties to establish a named session. The session creates a scope in which you can open multiple databases and conduct one instance of nested transactions.

• Use the Close method to terminate a session.

• Use the OpenDatabase method to open one or more existing databases on a Workspace.

• Use the BeginTrans, CommitTrans, and Rollback methods to manage nested transaction processing within a Workspace and use several Workspace objects to conduct multiple, simultaneous, and overlapping transactions.

When you first refer to or use a Workspace object, you automatically create the default workspace, DBEngine.Workspaces(0). The settings of the Name and UserName properties of the default workspace are "#Default Workspace#" and "Admin," respectively. If security is enabled, the UserName property setting is the name of the user who logged on.

When you use transactions, all databases in the specified Workspace are affected— even if multiple Database objects are opened in the Workspace. For example, you use a BeginTrans method, update several records in a database, and then delete records in another database. If you then use the Rollback method, both the update and delete operations are canceled and rolled back. You can create additional Workspace objects to manage transactions independently across Database objects.

You can create Workspace objects with the CreateWorkspace method. After you create a new Workspace object, you must append it to the Workspaces collection if you need to refer to it from the Workspaces collection.

You can use a newly created Workspace object without appending it to the Workspaces collection. However, you must refer to it by the object variable to which you have assigned it.

To refer to a Workspace object in a collection by its ordinal number or by its Name property setting, use any of the following syntax forms:

DBEngine.Workspaces(0)

DBEngine.Workspaces("name")

DBEngine.Workspaces![name]

Note

ODBCDirect workspaces are not supported in Microsoft Access 2010. Use ADO if you want to access external data sources without using the Microsoft Access database engine.

Example

This example creates a new Microsoft Access Workspace object and appends it to the Workspaces collection. It then enumerates the Workspaces collections and the Properties collection of the Workspace object.

Sub WorkspaceX() 
 
   Dim wrkNewAcc As Workspace 
   Dim wrkLoop As Workspace 
   Dim prpLoop As Property 
 
   ' Create a new Microsoft Access workspace. 
   Set wrkNewAcc = CreateWorkspace("NewAccessWorkspace", _ 
      "admin", "", dbUseJet) 
   Workspaces.Append wrkNewAcc 
 
   ' Enumerate the Workspaces collection. 
   For Each wrkLoop In Workspaces 
      With wrkLoop 
         Debug.Print "Properties of " & .Name 
         ' Enumerate the Properties collection of the new 
         ' Workspace object. 
         For Each prpLoop In .Properties 
            On Error Resume Next 
            If prpLoop <> "" Then Debug.Print "  " & _ 
               prpLoop.Name & " = " & prpLoop 
            On Error GoTo 0 
         Next prpLoop 
      End With 
   Next wrkLoop 
 
   wrkNewAcc.Close 
End Sub 
 

This example uses the CreateWorkspace method to create a Microsoft Access workspace. It then lists the properties of theworkspace.

Sub CreateWorkspaceX() 
 
   Dim wrkAcc As Workspace 
   Dim wrkLoop As Workspace 
   Dim prpLoop As Property 
 
 
   DefaultType = dbUseJet 
   ' Create an unnamed Workspace object of the type  
   ' specified by the DefaultType property of DBEngine  
   ' (dbUseJet). 
   Set wrkAcc = CreateWorkspace("", "admin", "") 
 
   ' Enumerate Workspaces collection. 
   Debug.Print "Workspace objects in Workspaces collection:" 
   For Each wrkLoop In Workspaces 
      Debug.Print "  " & wrkLoop.Name 
   Next wrkLoop 
 
   With wrkAcc 
      ' Enumerate Properties collection of Microsoft Access  
      ' workspace. 
      Debug.Print _ 
         "Properties of unnamed Microsoft Access workspace" 
      On Error Resume Next 
      For Each prpLoop In .Properties 
         Debug.Print "  " & prpLoop.Name & " = " & prpLoop 
      Next prpLoop 
      On Error GoTo 0 
   End With 
 
   wrkAcc.Close 
 
End Sub 
 

The following example shows how to use a transaction in a Data Access Objects (DAO) workspace.

Sample code provided by: The Microsoft Access 2010 Programmer’s Reference | About the Contributors

Public Sub TransferFunds()
    Dim wrk As DAO.Workspace
    Dim dbC As DAO.Database
    Dim dbX As DAO.Database
    
    Set wrk = DBEngine(0)
    Set dbC = CurrentDb
    Set dbX = wrk.OpenDatabase("e:\books\acc2007vba\myDB.accdb")
    
    On Error GoTo trans_Err
    
    'Begin the transaction
    
    wrk.BeginTrans
    
    'Withdraw funds from one account table
    dbC.Execute "INSERT INTO tblAccounts ( Amount, Txn, TxnDate ) SELECT -20, 'DEBIT', Date()", dbFailOnError

    'Deposit funds into another account table
    dbX.Execute "INSERT INTO tblAccounts ( Amount, Txn, TxnDate ) SELECT 20, 'CREDIT', Date()", dbFailOnError
    
    'Commit the transaction
    wrk.CommitTrans dbForceOSFlush
    
trans_Exit:
    'Clean up
    wrk.Close
    Set dbC = Nothing
    Set dbX = Nothing
    Set wrk = Nothing
    Exit Sub
    
trans_Err:
    'Roll back the transaction
    wrk.Rollback
    Resume trans_Exit
    
End Sub

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