"Query opening was canceled during data fetching"

Discussion of open issues, suggestions and bugs regarding SDAC (SQL Server Data Access Components) for Delphi, C++Builder, Lazarus (and FPC)
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bryn.ball
Posts: 9
Joined: Mon 08 Dec 2014 03:32

"Query opening was canceled during data fetching"

Post by bryn.ball » Wed 06 Feb 2019 23:07

Can anyone shed light on how I can accurately identify what activity within my application could be causing the error message "Query opening was canceled during data fetching" to appear.

I am using Change Notification in my Delphi application and from time to time this message appears. I have the source code version of SDAC but that always traces back to an alternate thread and when I breakpoint the OnChange event of the MSChangeNotification component it does not correspond to any code in the event.

The issue appears to be connected with the timing between commit statements and I suspect it has a lot to do with the number of entries that need to be processed in the notification queue but as I am inexperienced in these matters I would like to understand the process better.

Also, is there a way I can initiate the processing of messages that may be in the notification queue rather than waiting for the notification queue thread to apply them?

Any help you can provide would be greatly appreciated.

Bryn

Stellar
Devart Team
Posts: 334
Joined: Tue 03 Oct 2017 11:00

Re: "Query opening was canceled during data fetching"

Post by Stellar » Tue 12 Feb 2019 15:34

The The "Query opening was canceled during data fetching" exception may occur before the fetch of the data block if the fetch was canceled from a different thread, or in the non-blocking mode. This is an internal SDAC exception and it should not be transmitted into the client application. Please, specify the version of SDAC you are using.

bryn.ball
Posts: 9
Joined: Mon 08 Dec 2014 03:32

Re: "Query opening was canceled during data fetching"

Post by bryn.ball » Mon 18 Feb 2019 23:42

Hi Stellar,

Sorry that it has taken a while to get back to you. I overlooked the "Notify me when a reply is posted" option when I posted my question.

I am using SDAC v8.2.9 (Professional with source code in RAD Studio XE7).

Thanks
Bryn

Stellar
Devart Team
Posts: 334
Joined: Tue 03 Oct 2017 11:00

Re: "Query opening was canceled during data fetching"

Post by Stellar » Fri 22 Feb 2019 13:35

Unfortunately, we can't reproduce the issue. To investigate this behavior of SDAC, please compose a small sample demonstrating the issue and send it to us, including database objects creating scripts.
You can send the sample using the contact form at our site: devart.com/company/contactform.html

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