Question

I have a SQL Server 2008 R2 stored procedure that runs a few INSERTs and UPDATEs in a TRANSACTION. After each statement, I need to log what just happened before doing the next step.

Here is my code:

BEGIN TRY

    BEGIN TRANSACTION

        INSERT INTO... -- 1st statement
        INSERT INTO MyEventLog (EventDescription) VALUES ('Did Step 1') -- log

        UPDATE... -- 2nd statement
        INSERT INTO MyEventLog (EventDescription) VALUES ('Did Step 2') -- log

    COMMIT TRANSACTION

END TRY

BEGIN CATCH
    IF (@@TRANCOUNT<>0) ROLLBACK TRANSACTION
    EXEC LogError 'I got an error'
END CATCH

Problem is: if there is an error, the transaction rolls back all statements — including the logging which I need. in the event of an error, how do I roll back the transactions but keep the logging.

Answer 1

I was going to ask why you would want to log an event that technically didn’t happen, since the transaction would have been rolled back and the database would be in the state it was in before the transaction. But then it occurred to me that you probably just want to log it in order to know WHERE it failed so you can fix the underlying issue, which is a smart thing to do.

If that is indeed the case, the best thing to do is to rollback the entire transaction as you are currently doing, and to use your LogError SP to log the error message in another table. This is what I use:

CREATE PROCEDURE [dbo].[Error_Handler]
@returnMessage bit = 'False'
WITH EXEC AS CALLER
AS
BEGIN

  DECLARE @number int,
    @severity int,
    @state int,
    @procedure varchar(100),
    @line int,
    @message varchar(4000)

  INSERT INTO Errors (Number,Severity,State,[Procedure],Line,[Message])
  VALUES (
    ERROR_NUMBER(),
    ERROR_SEVERITY(),
    ERROR_STATE(),
    isnull(ERROR_PROCEDURE(),'Ad-Hoc Query'),
    isnull(ERROR_LINE(),0),
    ERROR_MESSAGE())

  IF(@returnMessage = 'True')
  BEGIN
    select *
    from Errors
    where ErrorID = scope_identity()
  END
END

The error message should let you know what went wrong in what table, and that should be enough info to fix the problem.