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CREATE TRIGGER TRG_Tasks_UI ON Tasks FOR INSERT,UPDATE
AS
SET XACT_ABORT, NOCOUNT ON
--Ignore zero row updates, inserts
IF NOT EXISTS (SELECT * FROM INSERTED) RETURN;
BEGIN TRY
INSERT TasksHistory
(col1, col2, ...)
SELECT
I.*
FROM
INSERTED I
LEFT JOIN
DELETED D ON I.key = D.Key
WHERE
D.Key IS NULL --insert only
OR -- need null handling here
I.col1 <> D.col1 OR I.col2 <> D.col2 OR ...;
END TRY
BEGIN CATCH
IF XACT_STATE() <> 0 ROLLBACK TRANSACTION
RAISERROR [rethrow caught error using @ErrorNumber, @ErrorMessage, etc]
END CATCH
GO