Most efficient way of fetching 1,000 records from MySQL ?

Hello, In my script I have generated an array of 1,000 userIDs for example. Now for I need to fetch each user's record and I am wondering what is the best way to go about it: 1) 1000 sql queries // code is sort of pseudo for clarity foreach($users as $userID) { $user = sql("select * from users where userID = '$userID'"); // bla bla } 2) 1 query $users = sql("select * from users where userID='1' or userID='2' or userID='5' or userID='10'"); I imagine the 2nd one would be a bit of a nightmare for MySQL to parse, if it gets too long? Or am I missing a more efficient 3rd / 4th option? Many thanks in advance for your help. Steve McGill