[odb-users] Optimistic Concurrency : ROWVERSION exception

[Chew Kok Keng]

Pardon me for the missing subject

________________________________
From: Chew Kok Keng
Sent: Saturday, May 18, 2013 2:01 PM
To: odb-users at codesynthesis.com
Subject:

Hi,

I’m getting the following exception when I tried out ODB optimistic example

First-chance exception at 0x751a812f in driver.exe: Microsoft C++ exception: odb::mssql::database_exception at memory location 0x0015e8ec..

I’ve replaced the 2 lines in person class header with ROWVERSION type. See below.

//#pragma db version
//unsigned long version_;

#pragma db version type("ROWVERSION")
unsigned long long version_;


Here’s the line that the exception occurred.

      try
      {
        db->update (p2); // exception thrown here
      }
      catch (const object_changed&)
      {
        cout << "process 2 version is out of date: " << p2.version () << endl;

        // Reload the object and retry the operation. Note that the second
        // update call cannot throw object_changed since we reloaded the
        // object and are trying to update it in a single transaction.
        //
        db->reload (p2);

        cout << "process 2 version after reload: " << p2.version () << endl;

        p2.age (p2.age () + 1);
        db->update (p2);
      }

I’m uisng VC++ 2008 Express and SQl Server 2008 Express on windows 7 32bits. Could you let me know whether I’m doing anything wrong? or is this a genuine problem in ODB?

Thanks,
Chew