Insert records in parent-child tables within transaction: error 3155

Question

Guys, I'm completely out of ideas!

2 tables: tAssign, tAssignDetails.

tAssign.ID - PK, tAssignDetails.ID - PK, tAssignDetails.AssignID - FK. Other fields do not matter. It's a little program for planning trainings, assigning them to both trainers and trainees, tracking the process etc.

One very simple piece of code which should add a record about the training to tAssign table and then all the records about attendees to tAssignDetails table. The code is smth like that:

BeginTrans
Set rs = CurrentDb.OpenRecordset("tAssign", dbOpenDynaset, dbSeeChanges)
With rs
.AddNew
!TrainingID = Me.lst_training.Value
... 'field values setting
.Update
.Bookmark = .LastModified
ID = .Fields("ID").Value
.Close
End With
Set rs = CurrentDb.OpenRecordset("tAssignDetails", dbOpenDynaset, dbSeeChanges)
With rs
For i = 0 to UBound(u) 'u is just a string with attendees separated with comma
.AddNew
!AssignID = ID 'bla-bla
.Update ' the error appears here
Next i
.Close
End With
CommitTrans
'error handling with Rollback of course

Immediately after trying to update the first child record the system hangs and run-time error 3155 appears "ODBC--insert on a linked table 'tAssignDetails' failed".

I still can insert manually in table or a single record via VBA, but not within transaction. Ideas?

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 1

Hi Andrey,

Could it be that before the committrans the parent record is not really inserted in the parent table and so you can't add a child.

HTH Paolo

Answer 2

That was my exact same thought. Try removing the BeginTrans and Commit and see what happens

Answer 3

Hi Paolo and ATGNWT,

it shouldn't be so. That's why:

1. It worked as expected a couple of days ago. I've done some minor changes since that time and they have not related to this part of procedure. So I'm really wondering.

2. It is a piece of code. There is another one part of it where I modify the existing record in the parent table and add/delete child records. Again, all fails after trying to add a record. Note, this time the parent record exists.

Additionally, I don't believe that it's impossible to do such a simple action within transaction. 

If we look at this article http://msdn.microsoft.com/en-us/library/office/bb178042(v=office.12).aspx, we can see 3 possible reasons. They are not true for my case. But there is a good comment about possible lock by another user or process. I had a thought about making a real mistake while testing code and stopping the code with neither commited nor rolled back transaction. But I've deleted and recreated tAssignDetails table. Nothing changes.

If no one comes with an idea in the next 12 hours (I have access to this application only at my workplace), I think the next step is trying to move all this logic to the server side, make a stored proced with server side transaction. But who knows, maybe somebody has already faced this situation.

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 4

I have had problems in the past with timing issues with things like this because the records are not inserted immediately. Maybe if you insert a slight delay between these two statements?

End With

Set rs = CurrentDb.OpenRecordset("tAssignDetails", dbOpenDynaset, dbSeeChanges)

Answer 5

BTW, delay related issues often do not appear when yousing step-by-step with F8. And I still continue to see this annoying error. 

At least, now I'm sure it is possible within transaction http://social.msdn.microsoft.com/Forums/en-US/transactsql/thread/d06766c0-6893-4f7c-845f-4f4d5b40f8c8 see Naomi's post.

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 6

Finally, I'm lost. It works extremely well at the server side. It would be rather difficult for me to transfer all the logic from VBA to T-SQL, but if no one has any ideas, I will do it. New knowledge is always useful.

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 7

Hi Andrey

I'm not sure if this works as you do it. You should instantiate an explicit workspace object, in there instantiate an explicit database object and run your transaction in there:

Dim ws as Workspace
Dim db as Database
Set ws = DBEngine.Workspaces(0)
Set db = ws.Databases(0)
ws.BeginTrans
Set rs = db.OpenRecordset(....
'now run your transactions here using the db variable, never use CurrentDB in here!

ws.CommitTrans
set db = nothing
set wb = nothing

Finally you should be aware to always use dbFailOnError Option if you use db.Execute and in addition you should add an error handler that does the rollback if something went wrong.

HTH

Henry

Answer 8

Thanks Henry!

I've been always aware of this full (explicit) type if reference to objects, but haven't faced any issues with my style as of yet. Unfortunately, I did all the changes you recommended, but the result is still the same.

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 9

How does your code look now?

Henry

Answer 10

Also check what errors are in the Errors() Collection, for example:

? Errors(0).Description

Could be you miss something else.

HTH

Henry

Answer 11

Ok, full code of this routine

Private Sub btn_Save_Click() 
Dim i%, rs As DAO.Recordset, ID As Long, u As Variant, caller$, _ 
array1$, array2$, strSQL$, rs_Edit As DAO.Recordset, db As DAO.Database, ws As DAO.Workspace 
On Error GoTo err_lbl 
    caller = getByName("Caller", Nz(Me.OpenArgs)) 
    If caller = "NewDate" And _ 
    (Me.txt_Date.Tag = DateAdd("n", Me.txt_Minutes.Value, DateAdd("h", Me.txt_Hours, Me.txt_Date.Value)) _ 
    And Me.txt_End.Tag = Me.txt_End.Value) Then 
        MsgBox "Change date!!", vbCritical, "MyApp" 
        Exit Sub 
    End If 
    btn_CheckResources_Click 
    If IsConflicted Then 
        MsgBox "Resource conflict detected!", vbCritical, "MyApp" 
        Exit Sub 
    End If 
    Me.lst_ChosenUsers.Requery 
    If IsNull(Me.lst_ChosenUsers.Column(0, 0)) Then 
        MsgBox "choose attendees!", vbExclamation, "MyApp" 
        Exit Sub 
    End If 
    If Me.cmb_Room.Value & vbNullString = vbNullString Then 
        MsgBox "Choose room!", vbExclamation, "MyApp" 
        Exit Sub 
    End If 
    If Me.cmb_Trainer.Value & vbNullString = vbNullString Then 
        MsgBox "Choose trainer!", vbExclamation, "MyApp" 
        Exit Sub 
    End If 
    Set ws = DBEngine.Workspaces(0) 
    Set db = ws.Databases(0) 
    ws.BeginTrans 
    Set rs = db.OpenRecordset("tAssign", dbOpenDynaset, dbSeeChanges) 
    With rs 
        Select Case caller 
        Case "NewDate", "New": 
            .AddNew 
        Case "Edit": 
            .FindFirst "[ID] = " & getByName("AssignId", Nz(Me.OpenArgs)) 
            .Edit 
        End Select 
        !TrainingID = Me.lst_training.Value 
        !BeginDate = DateAdd("n", Me.txt_Minutes.Value, DateAdd("h", Me.txt_Hours, Me.txt_Date.Value)) 
        !EndDate = Me.txt_End.Value 
        !TrainerID = Me.cmb_Trainer.Value 
        !RoomID = Me.cmb_Room.Value 
        !FullStatusID = 1 
        .Update 
        Select Case caller 
        Case "New", "NewDate": 
            .Bookmark = .LastModified 
            ID = .Fields("ID").Value 
        Case "Edit": 
            ID = getByName("AssignId", Nz(Me.OpenArgs)) 
        End Select 
        .Close 
    End With 
    u = Split(Me.txt_UserList.Value, ",") 
    strSQL = "SELECT Login FROM tAssignDetails WHERE AssignID = " & ID 
    Set rs = db.OpenRecordset(strSQL, dbOpenSnapshot) 
    array1 = GetString(rs, , ",", ",") 
    array2 = Replace(Me.txt_UserList.Value, """", vbNullString) 
    rs.Close 
    Set rs = db.OpenRecordset("tAssignDetails", dbOpenDynaset, dbSeeChanges) 
    With rs 
        Select Case caller 
        Case "New", "NewDate": 
            For i = 0 To UBound(u) 
                .AddNew 
                !AssignId = ID 
                !Login = Replace(u(i), """", vbNullString) 
                !StatusID = 1 
                .Update '<--- the process is being locked here 
            Next i 
        Case "Edit": 
            strSQL = "exec bicolumn_symmetric_difference '" & array1 & "','" & array2 & "'" 
            Set rs_Edit = GetPTQ(strSQL, True).OpenRecordset(dbOpenSnapshot) 
            While Not rs_Edit.EOF 
                If Not IsNull(rs_Edit.Fields("Delete").Value) Then 
                    .FindFirst "[Login] = """ & rs_Edit.Fields("Delete").Value & """" 
                    .Delete 
                End If 
                If Not IsNull(rs_Edit.Fields("Add").Value) Then 
                    .AddNew 
                    !AssignId = ID 
                    !Login = rs_Edit.Fields("Add").Value 
                    !StatusID = 1 
                    .Update '<---- or here in Edit scenario 
                End If 
                rs_Edit.MoveNext 
            Wend 
            rs_Edit.Close 
        End Select 
        .Close 
    End With 
    If caller = "NewDate" Then 
        strSQL = "UPDATE tAssign SET [FullStatusID] = 4 WHERE ID = " & getByName("AssignId", Nz(Me.OpenArgs)) 
        db.Execute strSQL, dbFailOnError + dbSeeChanges 
        strSQL = "UPDATE tAssignDetails SET [StatusID] = 4 WHERE AssignID = " & getByName("AssignId", Nz(Me.OpenArgs)) 
        db.Execute strSQL, dbFailOnError + dbSeeChanges '<---BTW, this part works well if I comment the previous .Update statement 
    End If 
    ws.CommitTrans 
    Select Case caller 
    Case "New": 
        MsgBox "bla-bla1", vbInformation, "MyApp" 
    Case "Edit": 
        MsgBox "bla-bla2!", vbInformation, "MyApp" 
    Case "NewDate" 
        MsgBox "bla-bla3!", vbInformation, "MyApp" 
    End Select 
    DoCmd.Close acForm, Me.Name, acSaveNo 
exit_lbl: 
On Error Resume Next 
    rs.Close 
    Exit Sub 
err_lbl: 
    ws.Rollback 
    MsgBox UDM, vbCritical, "MyApp" 
    Resume exit_lbl 
End Sub 

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 12

As for Errors(0) item, I saw it earlier but didn't mention. Nothing interesting - Query timeout expired. Obviously, the table is locked! But why and by which process?

P.S. It's extremely difficult to write all this stuff from my phone, sorry in advance for kinda errors, typos and other strange things on my text. :)

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 13

        !TrainingID = Me.lst_training.Value 
        !BeginDate = DateAdd("n", Me.txt_Minutes.Value, DateAdd("h", Me.txt_Hours, Me.txt_Date.Value)) 
        !EndDate = Me.txt_End.Value 
        !TrainerID = Me.cmb_Trainer.Value 
        !RoomID = Me.cmb_Room.Value 
        !FullStatusID = 1 
        .Update 
        Select Case caller 
        Case "New", "NewDate": 
            .Bookmark = .LastModified 
            ID = .Fields("ID").Value 
        Case "Edit": 
            ID = getByName("AssignId", Nz(Me.OpenArgs)) 
        End Select 
        .Close 

Hi Andrey,

It does not solve your problem, but in my opinion you could simplify your program a little bit, by re-placing the assignment of ID:

        !TrainingID = Me.lst_training.Value 
        !BeginDate = DateAdd("n", Me.txt_Minutes.Value, DateAdd("h", Me.txt_Hours, Me.txt_Date.Value)) 
        !EndDate = Me.txt_End.Value 
        !TrainerID = Me.cmb_Trainer.Value 
        !RoomID = Me.cmb_Room.Value 
        !FullStatusID = 1 
        ID = !ID.Value
        .Update 
        .Close 

Imb.

Answer 14

I see.I had similar problems some time ago.IIRC it was  lock as you guess. Not sure anymore what I did.

I'll try to find it on Monday if you dudn't find a solution yet

Answer 15

Thanks Henry! I will be interesting in the solution anyway, all these "WHILE @@FETCH_STATUS = 0"s drive me crazy. But I've almost finished with making a stored procedure with the same logic. Frankly, VBA seems to be a bit easier for me.

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 16

Hi Andrey

I tried everything but I couldn't get into the same lock situation as you did. I posted my code below, maybe you find a difference in there to your code.

The only reason I can imagine is that you get or hold somehow a lock to your details table from somewhere else, for example from a form. The best way to investigate this issue is to run the SQL Server Management Studio, in there go to the Management and then use the Activity Monitor to examine the Process Info and the Locks. Then go through your code, step by step and check where the lock is established.

Just one simple question: Do your tables have a TimeStamp (RowNumber) column? I've seen many situation where this helped, but not sure if it helps here, too, but sure is a must for all linked tables to Access when you are doing updates to these tables.

If you can't solve it this way then probably the best (and most stable) way to do it is how you did it, using a stored procedure and T-SQL.

Sorry for not being able to help directly but without your data constellation (including tables, indexes) I'm not able to reproduce it.

Henry

Here my code:

Public Function testTransactions(Optional EditID As Variant)
On Error GoTo PROC_ERR
  Dim ws As Workspace
  Dim db As Database
  Dim rs As Recordset
  Dim ID As Long
  Set ws = DBEngine.Workspaces(0)
  Set db = ws.Databases(0)
  ws.BeginTrans
  ' add new master record
  If IsMissing(EditID) Then
    Set rs = db.OpenRecordset("tAssign", dbOpenDynaset, dbSeeChanges)
    rs.AddNew
  Else
    Set rs = db.OpenRecordset("SELECT * FROM tAssign WHERE ID = " & EditID, dbOpenDynaset, dbSeeChanges)
    rs.Edit
  End If
  rs!MasterText = "New Master Text of " & Now()
  rs.Update
  If IsMissing(EditID) Then
    rs.Bookmark = rs.LastModified
    ID = rs!ID
  Else
    ID = EditID
  End If
  rs.Close
  
  ' add detail record to the new master record
  If IsMissing(EditID) Then
    Set rs = db.OpenRecordset("tAssignDetails", dbOpenDynaset, dbSeeChanges)
    rs.AddNew
    rs!assignid = ID
  Else
    Set rs = db.OpenRecordset("SELECT * FROM tAssignDetails WHERE assignID = " & ID, dbOpenDynaset, dbSeeChanges)
    rs.Edit
  End If
  rs!DetailText = "New Detail Text for ID " & ID & " of " & Now()
  rs.Update
  rs.Close
  Set rs = Nothing
  If MsgBox("Commit changes to database?", vbQuestion + vbYesNo) = vbYes Then
    ws.CommitTrans
  Else
    ws.Rollback
  End If
  
PROC_EXIT:
  On Error Resume Next
  Set db = Nothing
  Set ws = Nothing
  Exit Function
  
PROC_ERR:
  MsgBox Err.Description & vbCrLf & Errors(0).Description
  On Error Resume Next
  ws.Rollback
  GoTo PROC_EXIT
  
End Function

tested it in the immediate window using testTransactions without parameter to add records and with the ID of the master record to edit records.

Answer 17

Just some another ideas:

I see you always get a recordset based on the complete table without a WHERE condition. You then jump to the record you want to edit with "FindFirst". This doesn't make sense. You should (as I did in my code) use a WHERE condition instead. It could be,  that with "FindFirst", you establish a lock on the table that later is blocking the update.

Your passthrough query is based on the stored procedure "bicolumn_symetric_difference", correct? I maybe wrong but normally stored procedures are not updateable within Access, so I don't know if this can work at all. Is there any chance that you - instead of using a passthrough query rs_edit use a sql statement that is based on the linked tables instead?

Henry

Answer 18

Hi Henry,

thanks a lot for trying! Here are the results:

1. The fact you can't reproduce the issue proves that it is possible that it worked for me. And the issue really appeared suddenly.

2. I don't see any difference in our codes as well.

3. Timestamp. No, I don't. But I added it to both tables, but still no difference.

4. Where clause in recordsets. Yes, my fault, forgot to change it back while testing. Now I made changes, but still no result.

5. Pass-through query. Maybe the name rs_Edit has mislead you, but this recordset is not being update. It's a kind of helper recordset, it has info about which attendees I should remove from the list and which - add. Symmetric difference is a set of elements which are in either of two sets and not in their intersection (the union without the intersection). It's really easy to make this with SQL (full join) rather than bother with arrays in VBA.

Finally, unfortunately, I have no time to test further and I've already completed the stored proc which I will post later. Was a good lesson of T-SQL for me. :) Thanks anyway for your support! 

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 19

And here is the first part of BINGO!

The issue is file dependent. I created a simple sub which updates 4 records one-by-one in one database in one table. It works immediately in another .mdb, but fails again in my original .accdb.

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 20

The list of settings which do not affect the issue:

1. Decompilation.

2. Default record locking.

3. Record-level locking.

4. Access 2010 Cache features.

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 21

And now the BINGO itself!!! You will never guess. 2 characters which killed my 3 working days!!!

I don't know the reason but the difference was in connection string.

DRIVER={SQL SERVER} - does not work

DRIVER=SQL SERVER -works!

I've been using the first connection string for years for another app and have never faced such issue. Who knows...

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 22

For my great surprise, rewriting this logic to a stored proc took a couple of hours only. For those who is interested in T-SQL realisation, here it is:

/****** Object:  StoredProcedure [dbo].[AssignTraining]    Script Date: 04.02.2013 18:40:43 ******/ 
SET ANSI_NULLS ON 
GO 
SET QUOTED_IDENTIFIER ON 
GO 
-- ============================================= 
-- Author:      Andrey Artemyev 
-- Create date: 2013-02-04 
-- Description:         
-- ============================================= 
ALTER PROCEDURE [dbo].[AssignTraining] 
        -- Add the parameters for the stored procedure here 
        @caller nvarchar(20), 
        @TrainingID int, 
        @BeginDate datetime, 
        @EndDate datetime, 
        @TrainerID nvarchar(8), 
        @RoomID int, 
        @emplist nvarchar(max), 
        @AssignID int 
AS 
BEGIN 
        -- SET NOCOUNT ON added to prevent extra result sets from 
        -- interfering with SELECT statements. 
        SET NOCOUNT ON; 
        DECLARE @T table (id int) 
        DECLARE @diff table ([add] nvarchar(8), [delete] nvarchar(8)) 
        DECLARE @myID int 
        DECLARE @empTable table (login nvarchar(8)) 
        DECLARE @add nvarchar(8) 
        DECLARE @delete nvarchar(8) 
        DECLARE @currEmp nvarchar(8) 
        DECLARE @emplist_old nvarchar(max) = '' 
        BEGIN TRY 
                INSERT INTO @empTable SELECT * FROM dbo.CSV2TempTable(@emplist) 
                BEGIN TRANSACTION T1 
                IF @caller = 'New' OR @caller = 'NewDate' 
                BEGIN 
                        INSERT INTO dbo.tAssign ([TrainingID],[BeginDate],[EndDate],[TrainerID],[RoomID],[FullStatusID]) 
                        OUTPUT inserted.ID INTO @T 
                        VALUES (@TrainingID,@BeginDate,@EndDate,@TrainerID,@RoomID,1) 
                        SELECT @myID = id FROM @T 
                        DECLARE details_cursor CURSOR FOR 
                        SELECT [Login] FROM @empTable 
                        OPEN details_cursor 
                        FETCH NEXT FROM details_cursor INTO @currEmp 
                        WHILE @@FETCH_STATUS = 0 
                        BEGIN 
                                INSERT INTO dbo.tAssignDetails ([AssignID],[Login],[StatusID]) 
                                VALUES (@myID,@currEmp,1) 
                                FETCH NEXT FROM details_cursor INTO @currEmp 
                        END 
                        CLOSE details_cursor 
                        DEALLOCATE details_cursor 
                END 
                IF @caller = 'Edit' 
                BEGIN 
                        SET @myID = @AssignID 
                        UPDATE dbo.tAssign SET [TrainingID]=@TrainingID,[BeginDate]=@BeginDate,[EndDate]=@EndDate, 
                        [TrainerID]=@TrainerID,[RoomID]=@RoomID 
                        WHERE dbo.tAssign.id = @myID 
                        DECLARE array_cursor CURSOR FOR 
                        SELECT Login FROM tAssignDetails WHERE AssignID = @myID 
                        OPEN array_cursor 
                        FETCH NEXT FROM array_cursor INTO @currEmp 
                        WHILE @@FETCH_STATUS = 0 
                        BEGIN 
                                SET @emplist_old = @emplist_old + @currEmp + ',' 
                                FETCH NEXT FROM array_cursor INTO @currEmp 
                        END 
                        CLOSE array_cursor 
                        DEALLOCATE array_cursor 
                        SET @emplist_old = LEFT(@emplist_old,LEN(@emplist_old)-1) 
                        INSERT INTO @diff exec dbo.bicolumn_symmetric_difference @emplist_old, @emplist 
                        DECLARE details_cursor CURSOR FOR 
                        SELECT * FROM @diff 
                        OPEN details_cursor 
                        FETCH NEXT FROM details_cursor into @delete, @add 
                        WHILE @@FETCH_STATUS = 0 
                        BEGIN 
                                IF @delete IS NOT NULL 
                                BEGIN 
                                        DELETE FROM dbo.tAssignDetails 
                                        WHERE [Login] = @delete 
                                        AND [AssignID] = @myID 
                                END 
                                IF @add IS NOT NULL 
                                BEGIN 
                                        INSERT INTO dbo.tAssignDetails (AssignID, [Login], StatusID) 
                                        VALUES(@myID, @add, 1) 
                                END 
                                FETCH NEXT FROM details_cursor into @delete, @add 
                        END 
                        CLOSE details_cursor 
                        DEALLOCATE details_cursor 
                END 
                IF @caller = 'NewDate' 
                   BEGIN 
                        UPDATE dbo.tAssign SET [FullStatusID] = 4, [NewDateRef] = @myID WHERE ID = @AssignID 
                        UPDATE dbo.tAssignDetails SET [StatusID] = 4 WHERE AssignID = @AssignID 
                END 
                COMMIT TRANSACTION T1 
                SELECT 'OK' AS [Result] 
        END TRY 
        BEGIN CATCH 
                SELECT 
                        'ERROR' AS [Result], 
                        ERROR_NUMBER() AS ErrorNumber, 
                        ERROR_SEVERITY() AS ErrorSeverity, 
                        ERROR_STATE() AS ErrorState, 
                        ERROR_PROCEDURE() AS ErrorProcedure, 
                        ERROR_LINE() AS ErrorLine, 
                        ERROR_MESSAGE() AS ErrorMessage; 
                ROLLBACK TRANSACTION T1 
        END CATCH 
END 

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 23

You are dns-less ODBC connections, correct?

Anyway that's strange. This was the only difference in the ODBC connect string? When I look at the documentation {...} should be ok or at least was ok in previous versions. Maybe something changed here.

This newer KB article of MS doesn't include the {}: http://support.microsoft.com/kb/892490

But this KB article does include it: http://support.microsoft.com/kb/147875

Henry

Answer 24

Yes, I see. Are they really different drivers?

And yes, this is the only difference. That's how I found it:

I have a DSN just to quickly link new tables if any. I linked these 2 my tables to another Access 2003. And all was OK. Then I run the Sturtup form which relinks all tables with DSN-less connection and get the same error. DSN has no {}, but my connection string for DSN-less connection has. I change my INI file where this connection string resides by removing {} around SQL Server and it begins to work as expected. I add them again - the same error again. This behaviour is valid for both A2003 and A2010. What's interesting, I used transaction before in this A2003 file with {} in its connection string and had no issues. But all these transactions had no parent-child tables included in UPDATE/INSERT process, as far as I remember. 

---

Andrey V Artemyev | Saint-Petersburg, Russia
Russian blog artemyev.biztoolbox.ru

Answer 25

Hi Andrey

I really don't know the difference using {} or not. I didn't find it in any documentation. Some use it others don't. Same drivers? I don't know. I - same as you did - just become aware of this difference.

Henry