random image thingy won't work

mashnote

Ok, a while ago i got a piece of code & adapted it a bit to generate random images with php.

this is the code

      <?
        $seed = srand((double) microtime() * 1000); 
        $result = mysql_query("SELECT * FROM mash_banners  ORDER BY RAND($seed) LIMIT 1"); 

       ?>

so i got some images + urls (they're banners) in my db. the strange thing is:
when i try it on my localhost, it works fine. on my website (www.mashnote.net) it seems that only the first entry in my db shows up everytime.

help........?

sijis

in true honesty, i've never deal with srand(), but I thought it was a simple question, that i might be able to answer.

I've noticed that if you try to echo the value of $seed you don't get one! I'm not exactly sure why, but I think i have a reason. I think it is because srand() isn't really suppose to give you a value, it somehow helps the rand() function to get a random value.
now once I added the $random var using rand() i did get an output.
if i removed the $seed var, i still got an output for $random.
I might be missing something, but I didn't notice a correlation between srand() and rand(), which i thought there was one... ?

so it basically comes out that you have to do something like this:

$seed = srand((double) microtime() * 1000); // you can optionally remove this line
// $random = rand(); // any whole positive number, I guess between the max $seed range....
$random = rand(1,20); //values between 1-20
$result = mysql_query("SELECT * FROM mash_banners ORDER BY RAND($random) LIMIT 1");

this should give you something....

my sources: (also check out the user comments)

notice the use of rand() in the example
http://us3.php.net/manual/en/function.srand.php

look for the rand() function.
http://www.mysql.com/doc/en/Mathematical_functions.html

hope that helps.

dv6cougar

actually there's a much easier way to do this...


$result = mysql_query("SELECT * FROM mash_banners ORDER BY rand() LIMIT 1");

you dont' need to make the $random variable, it's already made in mysql and it the rand() function it self works quite well... for an exmaple you can see this gallery of mine

www.tunercarz.com/db/gallery/random.php

hope this helps. 🆒

mashnote

thanx a lot for your replies ! I'll try out your suggestions in a minute, and let you know how it's going 😉

The_Chancer

It depends on the PHP version as to whether you need the srand() function... I believe it is PHP >4.2 where you don't need it anymore...