select by either field

[zzz]

I have a table with two possible IDs for a user. Can I run a query to match a user where given var ($key) matches at least one of the columns in user records?

SELECT user
FROM t1
WHERE
(userkey1 = '".$key."')
OR
(userkey2 = '".$key."')

[zzz]

Apparently this is a faster solution:

SELECT user FROM t1 WHERE userkey1 = '".$key."'
UNION
SELECT user FROM t1 WHERE userkey2 = '".$key."'

[bradgrafelman]

One other possibility:

SELECT user FROM t1 WHERE 'foo' IN (userkey1, userkey2)