I think I would create a lookup table, like this:

CREATE TABLE CodeActions (

Code char(4)

,TheActionvarchar(12)

)

INSERT INTO CodeActions (Code,TheAction)

VALUES

('ISSP','Install'),

('IECO','Install'),

('IECM','Install'),

('IESP','Install'),

('IEHD','Install'),

('ISHD','Install'),

('FRSI','Install'),

('SB42','Service Call'),

('SB4W','Service Call'),

('HD42','Service Call'),

('HD4W','Service Call'),

('SA2C','Service Call'),

('SA2W','Service Call'),

('HD2C','Service Call'),

('HD2W','Service Call'),

('SNCO','Service Call')

That way you don't have to play about with lengthy function definitions, nor rewrite them every time a code changes.

Your function becomes:

ALTER FUNCTION [dbo].[Tester] (@jdt_jty_code varchar(50))

Returns varchar(50)

as

Begin

Return

SELECT

COALESCE(TheAction,'UNKNOWN')

FROM

CodeActions

WHERE

Code = @jdt_jty_code

END

which is so trivial that you probably don't even need a function for it. If you decide to keep it, bear in mind what Chris said about table-valued vs scalar functions. If you're going to use this function on large amounts of data, you'll take a performance hit if you leave it like it is.

John