Can you cancel a running OleDB query?

[MJFShark]

Hi all!

I've been testing the TZConnection.AbortOperation method which works great for the supported drivers. I'm also using SQL Server through the OleDB interface, and it doesn't support this method, however I notice it has a "Cancel" method on the statement objects. Is that in any way similar? I tried using it but no luck (I think it doesn't do what I thought it might.) Any info appreciated!

-Mark

[aehimself]

Hi Mark,

I'm glad to hear it works fine for you :) I do believe I saw those too when I implemented the basics of the .AbortOperation logic. See ZDbcConnection.pas:1071:

Code: Select all

function TZAbstractDbcConnection.AbortOperation: Integer;
begin
//  Would this work...?
//  for i := fRegisteredStatements.Count-1 downto 0 do
//   IZStatement(fRegisteredStatements[i]).Cancel;
  Raise EZUnsupportedException.Create(SUnsupportedOperation);
end;

I implemented the "normal" way (telling the server to abort) where I could, but I had no chance to test on others as I have only a MySQL and an MSSQL server at home.

You can try to uncomment those lines and see if it works, I suppose?
But, even if we skip the execution of a statement on client side, either the query will still be running or simply resources will still be locked on the server side until it finishes... so be careful.