Visual Basic, DAO questions... DBEngine vs Workspace vs Database

DAO questions... DBEngine vs Workspace vs Database

Author	Message
G. Douce #1 / 4	DAO questions... DBEngine vs Workspace vs Database I am just starting a book on MS Jet DBEngine... This is all new to me. Assume that I dimension the following variables like this: Dim dbe As DBEngine Dim wsp As Workspace Dim dbs As Database I was wondering what the difference was between the following: - dbe.OpenDatabase(dbname) - wsp.OpenDatababe(dbname) Wouldn't you always use the latter. I mean, if you open the database through the DBEngine directly, it would seem as if there wasn't a workspace anymore, just a DBEngine and a Database. But to make things worst for me, My book shows an example such as: - Set dbs = OpenDatabase(dbname) So now it seems I have a database object without a workspace nor a DBEngine object, or at least I don't know how to refer to them. In the example, they didn't dimension a DBEngine nor a Workspace variable, so how could you access these? Any clarity would help... :-) Guy Doucet
Thu, 08 Aug 2002 03:00:00 GMT

Kerry Moorma #2 / 4	DAO questions... DBEngine vs Workspace vs Database Guy, For compatibility with code from earlier versions of VB and DAO, you can use OpenDatabase without explicitly creating Workspace and DBEngine objects. But when you use such a technique, for example: Set dbs = OpenDatabase(dbname) you are always using the default workspace, Workspaces (0), and you are always using the dbengine object, DBEngine. You can still refer to dbengine using DBEngine without explicitly dimensioning an object variable. And you can always refer to the default workspace, Workspaces(0), the zeroeth workspace object in the Workspaces collection. Hope this helps, Kerry Moorman Quote: >I am just starting a book on MS Jet DBEngine... This is all new to me. >Assume that I dimension the following variables like this: > Dim dbe As DBEngine > Dim wsp As Workspace > Dim dbs As Database >I was wondering what the difference was between the following: >- dbe.OpenDatabase(dbname) >- wsp.OpenDatababe(dbname) >Wouldn't you always use the latter. I mean, if you open the database >through the DBEngine directly, it would seem as if there wasn't a >workspace anymore, just a DBEngine and a Database. >But to make things worst for me, My book shows an example such as: >- Set dbs = OpenDatabase(dbname) >So now it seems I have a database object without a workspace nor a >DBEngine object, or at least I don't know how to refer to them. In the >example, they didn't dimension a DBEngine nor a Workspace variable, so >how could you access these? >Any clarity would help... :-) >Guy Doucet
Fri, 09 Aug 2002 03:00:00 GMT

EHJ #3 / 4	DAO questions... DBEngine vs Workspace vs Database As far as the DBEngine and worskpace objects go the explanation is fairly simple. DBengine represents the Jet Database engine installed on your machine. There is only one of these, and it is at the top of the DAO object hierarchy. It contains (among other things) a collection of workspaces. A workspace represents one session. For instance, all transactions (begintrans, committrans, rollback) occur at the workspace level, as do all username/password verifications. All databases are opened up within a workspace; when executing a OpenDatabase against the dbengine object one is actually performing an opendatabase against the default workspace. I'm unfamiliar with the OpenDatabase(dbname) syntax. Perhaps this is archaic? I'd imagine that this would also open a database into the default workspace. You could check this by trying to reference your database through the default workspace( Dbengine.workspaces(0) ) -EHJ
Fri, 09 Aug 2002 03:00:00 GMT

Remi Sabouri #4 / 4	DAO questions... DBEngine vs Workspace vs Database I've been using DAO for a while and I always do Dim db As DAO.Database Set db=DBEngine.OpenDatabase(.......) ....... This saves on code and is good if you want to use ADO also later on. Remi Quote: >I am just starting a book on MS Jet DBEngine... This is all new to me. >Assume that I dimension the following variables like this: > Dim dbe As DBEngine > Dim wsp As Workspace > Dim dbs As Database >I was wondering what the difference was between the following: >- dbe.OpenDatabase(dbname) >- wsp.OpenDatababe(dbname) >Wouldn't you always use the latter. I mean, if you open the database >through the DBEngine directly, it would seem as if there wasn't a >workspace anymore, just a DBEngine and a Database. >But to make things worst for me, My book shows an example such as: >- Set dbs = OpenDatabase(dbname) >So now it seems I have a database object without a workspace nor a >DBEngine object, or at least I don't know how to refer to them. In the >example, they didn't dimension a DBEngine nor a Workspace variable, so >how could you access these? >Any clarity would help... :-) >Guy Doucet
Sat, 10 Aug 2002 03:00:00 GMT

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