TMSQuery.Open corrupts memory

[Saupg]

Hello!

I try to upgrade my project from SDAC v5 to newest version (6.10).
I have very many strange exceptions about "Communication link failure", "... wrong TDS protocol ...", "... wrong format ..." and various "access violations" after it. Sometimes process freezes.

I try to debug this problem and found that "TMSQuery.Open" corrupts memory for some big SQL-queries (with using "Common table expressions", "OUTER\CROSS APPLY" and many joins).

And i can reproduce this problem in small projects!

I use Delphi XE and SQL Server 2005 SP4:

Code: Select all

Microsoft SQL Server 2005 - 9.00.5292.00 (X64) 
Apr 13 2011 15:43:31 
Copyright (c) 1988-2005 Microsoft Corporation
Developer Edition (64-bit) on Windows NT 5.2 (Build 3790: Service Pack 2)

Table for test query must have more then 1 column and primary key with more than 1 column:

Code: Select all

CREATE TABLE [dbo].[SDAC_BUG](
  ID SMALLINT NOT NULL,
  ID_PARENT SMALLINT NOT NULL
  CONSTRAINT [PK_SDAC_BUG] PRIMARY KEY (ID, ID_PARENT)
)

I use TMSConnection and TMSQuery with default properties.
I spent a lot of time to find a simple query for example:

Code: Select all

procedure TForm1.Button1Click(Sender: TObject);
const
  qTest =
    'WITH TEST (ID) AS ( ' +
    '  SELECT A.ID FROM SDAC_BUG A ' +
    '  LEFT JOIN SDAC_BUG B ON 1 = 2 ' +
    ') ' +
    'SELECT T.ID FROM SYS.OBJECTS GP ' +
    'LEFT JOIN TEST T ON 1 = 2';
begin
  MSConnection1.Open;
  MSQuery1.SQL.Text := qTest;
  MSQuery1.Open; // <--- Exception!
  MSConnection1.Close;
end;

With this query i have error: "Exception class EOLEDBError with message 'Ошибка протокола в потоке TDS'.".

If i change "LEFT JOIN" to "FULL JOIN" in last row, i have error: "Exception class EOLEDBError with message 'Соединение больше нельзя использовать, так как ответ сервера на выполнявшуюся ранее инструкцию имел неправильный формат.'".

If i change it to "INNER JOIN" or create table's primary key only for one column - i haven't any errors.

Please help!

[azyk]

Thank you for the information. We have reproduced the problem with access violation and fixed it.
To return the old behavior, you should set the TMSQuery.Options.UniqueRecords option to False.

[Saupg]

It's great, thank you!!!

[ismet]

Hi,
I also have this problem. When it is published?
Thanks,
Ismet Celebi

[azyk]

Hi,

If you want to get this fix, provide your e-mail address and license number to andreyz*devart*com and we will send you a custom build.

[ismet]

Hi Andrey,
I sent information
Thanks a lot.
Ismet

[ismet]

Hi,
Recently I sent you my license information.
But you still have not sent me acustom build.

Can you send me?

Thanks a lot.

Ismet Celebi

[azyk]

Hi,

We sent a custom build to your email.