When writing SQL procedures, it is really important to handle errors cautiously. Having that in mind will probably save your efforts, time and money. I have been working with MS-SQL 2000 and MS-SQL 2005 (I have not got the opportunity to work with MS-SQL 2008 yet) for many years now and I want to share with you how I handle errors in T-SQL Stored Procedure. This code has been working for many years now without a hitch.

N.B.: As antoher "best pratice", I suggest using only ONE level of TRY … CATCH and only ONE level of TRANSACTION encapsulation, as doing otherwise may not be 100% sure.

    BEGIN TRANSACTION;
    BEGIN TRY

    -- Code in transaction go here

    COMMIT TRANSACTION;

    END TRY BEGIN CATCH

        -- Rollback on error
        ROLLBACK TRANSACTION;

        -- Raise the error with the appropriate message and error severity
        DECLARE @ErrMsg nvarchar(4000), @ErrSeverity int;
        SELECT @ErrMsg = ERROR_MESSAGE(), @ErrSeverity = ERROR_SEVERITY();
        RAISERROR(@ErrMsg, @ErrSeverity, 1);

    END CATCH;

In conclusion, I will just mention that I have been using this code with .NET 2.0 and .NET 3.5 and it works like a charm. The .NET TDS parser throws back a SQLException which is ideal to work with.