PHP/MySQL / Use String to SELECT from Database

Question

I have a string:

 $string = "12,15,22";

Each of these values represents a usrID and I'd like to use these to select the rows associated with the $string.

Something like this:

SELECT usrFirst, usrLast FROM tblusers WHERE usrID = 12 OR 15 OR 22.

Now, the $string changes all the time, and sometimes can be a different number of ID's. Eg., sometimes 3, sometimes 4.

Thanks!

Answer 1

use IN, although it is very slow if you have lots of numbers:

SELECT usrFirst, usrLast FROM tblusers WHERE usrID IN ($string)

W3Schools has more info on IN.

If you have lots of numbers, have a look here for info on how to speed this up.

Answer 2

you can do something like:

SELECT usrFirst, usrLast FROM tblusers WHERE usrID in (12, 15, 22);

Answer 3

you can also do:

$string = str_replace(',',' OR usrID=',$string);
mysql_query('SELECT usrFirst, usrLast FROM tblusers WHERE usrID='.$string);