Problem with paging random results

[RonnyZenn]

hi,

I wrote a script to search the database and page the results.There is no problem upto here. But I want to display in different order each time. I tried to use ORDER BY rand() and it seems working but there are two problems with that,

First, as I cannot follow the order,sometimes same result(s) is diplayed in more than one page.

And the second problem is, when i click on the list to any link and then go back to list, the result list is changed as everytime ORDER BY rand() runs.

As far as I see ORDER BY rand() is not what i am looking for.I thought I could insert SQL results into array and then page the array to follow the order but again how am I gonna pass the array to next pages to follow the order?!

I am a bit mixed-up here. Could be great if someone could help me.

Cheers

[utexas_pjm]

This post assumes you're using MySQL.  The RAND() function takes as an optional argument an integer N which is used to "seed" the random float it returns.  This allows you to return predictable results when passing a constant N to RAND().  So what I would do is use a substring of the user's session_id to seed the RAND function as follows:

[code]
<?php
session_start();
$seed = hexdec(substr(session_id(), 0, 2));
$sql = 'SELECT `foo`, `bar` FROM `table` LIMIT 10 OFFSET 0 ORDER BY RAND('.$seed.')';
// ... etc
?>
[/code] 

Hope this helps.

Best,

Patrick

[utexas_pjm]

The SQL statement should read:

[code]
SELECT `foo`, `bar` FROM `table` ORDER BY RAND('.$seed.') LIMIT 10 OFFSET 0
[/code]

What happened to the moodify post option?

[RonnyZenn]

utexas_pjm, thank you for you answer.This way might be usefull also but as i was in a kind of hurry, i found and used someother technic. I would like to explain it here for other people who may be intereste in future.

What I did is, First I search with RAND() then put all the results into a SESSION, cookie could be used also, then I used session just like array and made pagination thru it.

Thank you again.