Question

What is the most elegant way to identify an error into transaction? At this time my code is like:

begin transaction tx1
update ....
insert ....
if @@error = 0
   commit
else
   rollback
end

This only catch last operation error, in this case errors on insert but not first operation error, in my case, update errors. How can I improve my code?

Answer 1

Have you looked at TRY/CATCH?

http://msdn.microsoft.com/en-us/library/ms175976.aspx

Of course you’ll still only be able to catch the first error that sent you into CATCH if you do something like this:

BEGIN TRANSACTION; -- not sure why you're using a named transaction

BEGIN TRY
  UPDATE ...
  INSERT ...
  COMMIT TRANSACTION;
END TRY
BEGIN CATCH
  PRINT ERROR_MESSAGE();
  ROLLBACK TRANSACTION;
END CATCH

But you can wrap each operation in its own TRY/CATCH, e.g.

BEGIN TRANSACTION; -- still not sure why you're using a named transaction

BEGIN TRY
  UPDATE ...
  COMMIT TRANSACTION;
END TRY
BEGIN CATCH
  PRINT ERROR_MESSAGE();
  ROLLBACK TRANSACTION;
END CATCH

BEGIN TRANSACTION;

BEGIN TRY
  INSERT ...
  COMMIT TRANSACTION;
END TRY
BEGIN CATCH
  PRINT ERROR_MESSAGE();
  ROLLBACK TRANSACTION;
END CATCH

But then I’m not sure what rules you’d want to follow here… do you want the insert to succeed if the update failed? If you want all actions to succeed or fail as a group then you want the first approach where everything is attempted in one TRY.

Also you should look at Erland Sommarskog’s bible on error handling:

http://www.sommarskog.se/error_handling_2005.html