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Régis CLUSEAU · Guest

Hi,
Strange behavior of DB2/400, when using an AdoQuery created dynamically.

I have a TDBGrid based on a TADOQuery "QryCand".
When doubleclic on a row, I intend to change the value of a column. But
before, doing so, I must ask in another AdoQuery if I am allowed.

procedure TForm1.DBGrid1DblClick(Sender: TObject);
begin
If AmIAllowed Then Begin
Dm.QryCand.Edit; // DM is the DataModule
If Dm.QryCand.FieldByName('Selected').AsBoolean = True Then
Dm.QryCand.FieldByName('Selected').AsBoolean := False
Else
Dm.QryCand.FieldByName('Selected').AsBoolean := True;
Dm.QryCand.Post;
End;
end;

function AmIAllowed : Boolean;
Var
AQry : TAdoQuery;
SqlCmd : String;
Begin
SqlCmd := 'SELECT * FROM TableXX WHERE yyyy ';
AQry := TADOQuery.Create(Nil);
AQry.Connection := AConnection;
AQry .CursorLocation := clUseClient;
AQry .CursorType := ctStatic;
AQry .Prepared := True;
...
AQry.Open;
If AQry.RecordCount > 0 Then
Result := True
Else
Result := False;
AQry.Close;
AQry.Free; // This Free cause a problem later.

End;

After QryCand.Post, I found in the log of the AS400, an error "Cursor Cx not
opened" with high severity.
The Delphi application is still working perfectely.
If "AQry.Free" is removed. I have no error in the log.

Strange isn't it ?

When an ADO query is freed (after a close), it seems, there is a dialog
between DB2 and the dataset.
Who knows ?
What can I do ?

There is the possibility to create the Query like this
TADOQuery.Create(AOwner) and leave the owner destroy the query when the
owner is freed. But the memory will be used for nothing, untill the end.

--
Régis CLUSEAU
[email]r.cluseau (AT) datasoft (DOT) fr[/email]

Régis CLUSEAU · Guest

I found out that the same problem appears on Visual Basic similar program.

Régis CLUSEAU

"Régis CLUSEAU" <r.cluseau (AT) datasoft (DOT) fr> a écrit dans le message news:
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Mark Smits · Guest

Are you using the Client Access ADO drivers ?

If yes, you may want to try turning on tracing, which will write some
logfiles. From a dos box enter the command cwbzztrc with no parameters
to see all possible options.

I always use the +a parameter. Don't forget to turn it off after you
are done. If you specify no filename with the -tf or -lf parameter the
files are usually written in the folder "My documentsIBMClient
AccessServiceTrace Files".

There is a lot of "garbage" in the tracefiles, that will not help you,
but you might find some clues. For example, you will find the complete
SQL that is sent to the AS400 when you use Post.

And you might see what communications there might be when freeing the
object.

Hope it helps.

Kind regards,
Mark Smits
--

Com-Unit BV, The Netherlands.
The makers of Spider-Road®.

On Thu, 18 Dec 2003 13:44:59 +0100, "Régis CLUSEAU"
<r.cluseau (AT) datasoft (DOT) fr> wrote:

Régis CLUSEAU · Guest

Hi,

In fact I have already used cwbzztrc log. But it does not help very much.
I have also used the IBM SQL performance monitor in order to visualise the
commands reaching DB2.
I discovered that the problem is the same in Visual Basic.
I am sure now that the problem is a bug on IBM side.
Thank-you for helping.

Régis CLUSEAU

"Mark Smits" <Smitsxxx (AT) xxxCom-Unit (DOT) com> a écrit dans le message news:
[email]5qb3uvcsn8p8qhmhfgnl9lde7oqq7b5i83 (AT) 4ax (DOT) com[/email]...