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Hi Team,

I've found a problem with CLOB fields in Unicode Oracle database which causes access violation when closing a Delphi VCL application. This problem appeared first in ODAC version 9.7.26. You can easily reproduce the AV with these steps:

1. 1. You need an Oracle database with AL32UTF8 character set and a table with at least one CLOB field.

1. 2. Create a new VCL Forms Application.

1. 3. Place a TOraSession component to the main form. Set the ConnectString property, LoginPrompt to False, Options.UnicodeEnvironment to True and Options.UseUnicode to True.

1. 4. Place a TOraQuery component and connect to the TOraSession. Use the OraQuery Editor to generate the Update SQLs for the table. The CLOB fields should be in the Update Fields!

1. 5. Place this code in the main form’s OnShow event:

1. Code: Select all

   procedure TForm1.FormShow(Sender: TObject);
   begin
     OraSession1.Connect;
   
     OraQuery1.Open;
   
     OraQuery1.Edit;
     OraQuery1.Post;
   
     OraQuery1.Close;
   
     OraSession1.Disconnect;
   end;

If you run the application an close it you will get the access violation in unit OraClasses!

if you remove the “OraSession1.Disconnect;” statement from the code there will be no AV when closing the application.

Best regards,

Balázs Miereisz
WINFORM Kft.

We will investigate the work of ODAC with CLOB fields and inform you about the results as soon as possible

Thank you for your information. We reproduced the issue and fixed it. Unfortunately, this fix was not included in the latest ODAC 9.7.28 build (21-Nov-2016). As a workaround we can send you a night build. For it provide us your license number and IDE version