How to Commit transaction even the trigger fails?

Question

Hi Everyone,
I got a situation here, i have two tables and a trigger. A main table and a log table. Whenever  a change happens in the main transaction ,   a log details will be inserted into the log table.
Am using sql server 2000 and "For insert,update,delete" in one trigger. 
I am in need of commiting the original transaction even if the trigger fails. I mean the main table is so important for me, so all the transaction should commit in the main table no matter if some transactions details missed in the log table.
I tried with
begin try
-- statement
end try
begin catch
commit transaction
end catch.
But it doesnt works. My insert fails whenever the trigger fails. i want the transaction should continue even if the trigger fails...
Pls suggest me how to do it.. Thanx for your help

Answer 1

If the trigger action is optional, it should not be in a trigger. The idea of a trigger is that it is part of the statement, so if the trigger fails, the statement fails.
As for what your alternatives are, it depends on which version on SQL Server you are using. You first say SQL 2000, but then you discuss TRY CATCH which was added in SQL 2005.
What always works is to have a separate process that scans the main table for changes and the update the log. It can be difficult to identify the changes, though. It helps if you are on SQL 2008 where you can use Change Tracking.
Another solution is to put a message on a Service Broker queue in the trigger, and then you have an activation procedure where you perform the operation with the log table. Of course, the SEND operation may fail, and you are back on square one. But it may
be less likely that this fails than producing the log operation if this is complex and fragile.
Also, a possibility is to add this statement to the trigger:
SET XACT_ABORT OFF
In this case, some errors in the trigger will not cause the statement to fail. More precisely, not errors that under normal circumstances terminates only the current statement, for instance PK violations, NOT NULL errors. There are still
plenty of errors that always aborts the batch and rolls back the open transaction. For instance, conversion errors often rolls back the transaction. Note that SET XACT_ABORT only has effect in SQL 2005 or later.
Erland Sommarskog, SQL Server MVP, [email protected]