Difference between DBEngine.BeginTrans and DBEngine.Workspaces(0).BeginTrans

Question

In Access, what is the difference between these two statements?

DBEngine.BeginTrans

and

DBEngine.Workspaces(0).BeginTrans

The documentation for both leads to the same place.

Answer 1

My own answer:

It appears that DBEngine.BeginTrans and DBEngine.Workspaces(0).BeginTrans do the same thing because this code works (see below). "Workspaces" is the default member of DBEngine.

Dim db As Database
Set db = CurrentDb

DBEngine.BeginTrans
db.Execute "Update Table1 SET CITY='Newark'"
DBEngine.Workspaces(0).Rollback

Answer 2

Have a look here: DAO Workspace
And then here: DAO Workspace: Opening a Separate Transaction Space

(The links are for MFC, but they're applicable to whatever you're coding in.)

DBEngine.Workspaces(0) is the default workspace. Other workspaces can be created, which let you work with separate sessions; the idea is that BeginTrans and EndTrans apply to the whole workspace, but if you need to do stuff outside that transaction, you can create another workspace and use it independently of your transactions in the first workspace.

Personally, I never had occasion to use more than one workspace when doing DAO in VBA. * shrug *

Answer 3

In the Access application interface, you can only have one database container open at a time. In VBA code, you can open multiple database instances within a Workspace. See the help file documentation for the Workspace.OpenDatabase method (or http://msdn.microsoft.com/en-us/library/bb243164.aspx) for an example where more than one Database is opened in one Workspace.

One would infer that when transactions are supported by all of the underlying Databases that are open in a Workspace, the BeginTrans method of the Workspace would apply across all of the databases. I suspect there be dragons there, but I'm sure it would work with two MDBs inside of one Workspace. When there's only one database open in the Workspace, Workspace.BeginTrans and Database.BeginTrans are indeed the same.

Answer 4

As Spock once said, a difference which makes no difference is no difference...