Random, but equal views

andrewm

Lets say I have 10 banners and I want to display them randomly, but have them each have the same number of views over the long term.

It doesn't appear to be working well with the mySQL RAND() function (sort by RAND() limit 1).

Any recommendations?

andrewm

I've tried looking through PhpAdsNew code, but I can't seem to find the code where they do it.

🙁

laserlight

sometimes you might have to seed RAND(), e.g. RAND(NOW())

conversely you could use PHP's pseudorandom number functions, i.e. rand() and mt_rand()

drawmack

there is an article on this site that explains how to do this.

you add a field to the database named shows and then when a banner shows you increment that field.

then you create a little function like this to retrieve

$sql = "SELECT shows FROM banners";
$query = mysql_query($sql);
$num = mysql_num_rows($query);
$total = 0;
for($i=0;$i<$num;$i++) {
    $total += mysql_result($query,$i,0);
} //end for

$epoch = ceil($total/$num);
if(!$total%$num) {$epoch++;}

$sql = "SELECT id from banners WHERE shows<$epoch ORDER BY rand LIMIT 0,1";

andrewm

Thanks guys. I'll give them a try 🙂

andrewm

Its working perfect!

Thanks drawmack!

drawmack

no problem please mark the thread resolved.

andrewm

Hmmm, looks like I've found a problem with it.

If a banner was to be activated mid day it would appear everytime until its views were even with the other banners (I'm tracking views by day).

I'll let you guys know if I come up with a solution to it.

drawmack

set up the php so that when you insert a new function is catches the banner up but using the query that calculates average views.

andrewm

I'm not sure that I understand you?

Sxooter

Let's say you're inserting a new row, and the column that stores number of views for the previous entered ads is called no_views:

insert into ads (ad_text,no_views) values ('ad text here',select avg(no_views) from ads);

Note if you don't have subselects, you can just use two selects with php in between them.

andrewm

Where would I be without guys like you guys. 🙂

I swear...