SQL where field in vs. where field = with multiple ors?

Question

Which of these is better to use in regard to performance? ...in regard to readability / understandability? ...in regard to accepted standards?

SELECT *
FROM Wher         


        

Answer 1

The IN version is much clearer and, since it's a single term, avoids the possibility of missing or incorrectly structured parentheses if you add other terms to the WHERE clause.

In addition, I believe that more SQL implementations will optimize the IN version assuming that an index is available.