Mysql query help !!! trying to select random user

Hi
my problem is the following:
I'm trying to select a random user..
so people can click "view random user profile"

as my provider is running older version of mysql i couldn't use the sort by rand() option.. but i found something that worked...

$radnomuser = $DB_site->query("SELECT *, userid*0+rand() as randomizer FROM user order by randomizer LIMIT 1");

works fine but:
How can I prevent that when user clicks "next random profile"
(such a button is put in the profile)

that he gets the same one or the ones he just viewed before...
would appreciate help very much!

(its driving me crazy!!! )

[Gimp]

try this

PHP Code:

if ($x != $xold){

$radnomuser = $DB_site->query("SELECT * FROM user WHERE userid = '$x'");

$xold = $x;
} else {
$numofusers// should be the total number of users u have i dont feel like writing here how to get em

$x = rand($numofusers);  

} 

[derfelix]

thanks for your help...

$x = rand($numofusers);
i had already thought of something similar.. the only problem is when you usernumbers in between that are empty...
i meen like
users: 1,2,3,4,5,8,12,14
users 6,7,9,10,11,13 have been deleted for whatever reason...
then the problem starts...

but the $xold = $x; part is great.. ill start testing immediately

[Gimp]

hmm yea that migh be a problem but heres the fix

PHP Code:

if ($x != $xold){

$uid = $DB_site->query("SELECT id FROM user WHERE userid = '$x'");

if (affected($uid)){
$radnomuser = $DB_site->query("SELECT * FROM user WHERE userid = '$x'");

$xold = $x;
} else {
$x = rand($numofusers);  
}
} else {
$numofusers// should be the total number of users u have i dont feel like writing here how to get em

$x = rand($numofusers);  

} 

[derfelix]

Well i tried to implement this..(yes i know how to get the number of users)

but the problem persists...

i think the problem lies else where..
i have to randomize the usernumbers and NOT the number of users

maybe my example was not clear enough:

- I have 5 users in db..users 1,2,5,12,11 and 13
actually i have to get the number of resultrows...
which are resultrows 1 to 5

- then i randomize the numbers 1 to 5 reslut: 3
it is not usernumber 3 i want to get (he doesn't exist by the way) but the third resultrow.

that is problem number 1

now to problem number 2:

supposed i solved that, if i randomize everytime i click a random profile, i can get if i do it 5 times:
rows: 1,3,3,4,1 which i dont want..
i want to be able to get:
1,5,3,4,2 for example... and the next time i do it 3,4,2,5,1 (for example)
i'm not so much interested in the exact code (i should be able to find it) but rather in the way to do it...
the code above

$radnomuser = $DB_site->query("SELECT *, userid*0+rand() as randomizer FROM user order by randomizer LIMIT 1");

works fine to give me ONE random profile.. (even in php3)
but it with 5 users for example it gives me at least 2 users twice in 5 goes... (which is normal when you randomly draw 5 objects out of bag)
any ideas?????
plz!!!