SQL SERVER 2008R2 Nested Transactions with RAISERROR - sql

Question

We are going through a process of switching from DB2 to SQL Server 2008R2 and I'm a bit unfamiliar with TSQL. Any help getting a better understanding of what is occurring would be nice. We've created a procedure called RethrowError as:
CREATE PROCEDURE RethrowError
AS
BEGIN
-- Return if there is no error information to retrieve.
IF ERROR_NUMBER() IS NULL
RETURN;
PRINT 'yo error';
DECLARE
#ErrorMessage NVARCHAR(4000),
#ErrorNumber INT,
#ErrorSeverity INT,
#ErrorState INT,
#ErrorLine INT,
#ErrorProcedure NVARCHAR(200);
-- Assign variables to error-handling functions that
-- capture information for RAISERROR.
SELECT
#ErrorNumber = ERROR_NUMBER(),
#ErrorSeverity = ERROR_SEVERITY(),
#ErrorState = ERROR_STATE(),
#ErrorLine = ERROR_LINE(),
#ErrorProcedure = ISNULL(ERROR_PROCEDURE(), '-');
-- Build the message string that will contain original
-- error information.
SELECT #ErrorMessage = N'Error %d, Level %d, State %d, Procedure %s, Line %d, ' +
'Message: '+ ERROR_MESSAGE();
PRINT 'yo doin something';
-- Raise an error: msg_str parameter of RAISERROR will contain
-- the original error information.
RAISERROR
(
#ErrorMessage,
#ErrorSeverity,
1,
#ErrorNumber, -- parameter: original error number.
#ErrorSeverity, -- parameter: original error severity.
#ErrorState, -- parameter: original error state.
#ErrorProcedure, -- parameter: original error procedure name.
#ErrorLine -- parameter: original error line number.
);
PRINT 'yo end';
RETURN;
END
GO
The reason we created the procedure is purely to expand on errors in the future without having to touch all the procedures. I've added some PRINT lines for debugging purposes.
My main question is that we have procedure A and on failure it executes RethrowError and I'll see the messages
yo error
yo doin something
yo end
as expected.
CREATE PROCEDURE dbo.A
AS
BEGIN
SET NOCOUNT ON;
DECLARE & SET VARIABLES;
BEGIN TRY
BEGIN TRANSACTION MaintainTarget
DO SOME STUFF
END TRY
BEGIN CATCH
EXEC RethrowError;
IF (XACT_STATE()) = -1
BEGIN
PRINT
N'The transaction is in an uncommittable state. ' +
'Rolling back transaction.'
ROLLBACK TRANSACTION;
END;
IF (XACT_STATE()) = 1
BEGIN
PRINT
N'The transaction is committable. ' +
'Rolling back transaction.'
ROLLBACK TRANSACTION;
END;
RETURN -101;
END CATCH;
RETURN;
END
GO
However, we've created a procedure that executes many procedures and when a nested procedure (ie procedure A being called by procedure B) fails the only messages I see are
yo error
yo doin something
I'm don't quite understand why the last message no longer shows up.
The procedure B is similar to procedure A but with a little difference in the catch.
CREATE PROCEDURE dbo.B
AS
BEGIN
SET NOCOUNT ON;
DECLARE & SET VARIABLES;
BEGIN TRY
DO SOME STUFF
END TRY
BEGIN CATCH
COMMIT;
RETURN -101;
END CATCH;
RETURN;
END
Any help on getting a better understanding what is happening would be appreciated.

Answer 1

I allowed myself to edit your code to mimic the bahaviour, but keep it simple (your job, actually ;).
Your procA works fine, because RethrowError procedure is being called inside CATCH block of procA and everything executes. But in your second case, it all still happens inside TRY block of procB! So CATCH part of procB fires immediately after RAISERROR in RethrowError is called.
This simple example demonstrates this behaviour of TRY-CATCH:
begin try
select 1/0
print 'doesnt show - div error'
end try
begin catch
print 'oops'
select 1/0
print 'this one shows because its in CATCH!'
end catch
And here's your simplified code:
-- "proc B" start
begin try
-- "proc A" start (works fine alone)
begin try
begin tran
select 1/0 --error
end try
begin catch
print 'yo error';
RAISERROR ('RE from RethrowError', 16, 1) --comment this out and see what happens
print 'yo end';
IF (XACT_STATE())=-1 or (XACT_STATE())=1
BEGIN
PRINT N'Rolling back transaction.'
ROLLBACK TRANSACTION;
end
end catch -- "proc A" ends
end try
begin catch
select error_message(), error_severity(), error_state() --
print 'outer catch';
commit;
end catch;
Hope this helps.