What is the Difference Between these IF statements

Question

Hello
Can someone tell me the difference between these two IF statements.
-- IF STATEMENT 1--
IF v_transcode not in ('A','C','D') THEN
raise_application_error (-20000, 'Error Invalid Transcation Code');
END IF;
-- IF STATEMENT 2 --
IF v_transcode <> 'A' AND v_transcode <> 'C' AND v_transcode <> 'D' THEN          
raise_application_error (-20000, 'Error Invalid Transcation Code');
END IF;
Thanks

Answer 1

Your if condition wherein you do
v_transcode <> 'A' and v_transcode <> 'C' and v_transcode <> 'D'.
I would think this is more better in terms of performance, because if the first clause (v_transcode <> 'A') fails nothing else needs to be evaluated, and it can skip the if condition there itself,
but in case of
v_transcode not in ('A', 'C','D'),
it has to scan through the entire list.
On the other side, if you have just 2 or 3 values to compare this makes sense, otherwise we may have to use the in operator.
--Bhargavi