Rotating links page

[Anon]

Hello. I'm using the code below to run a query that generates a links page. I write the results out to a file so I can use crontab to run the query only every 24 hours, rather than every time a surfer hits the page. The timing works great, but I have one last detail I’m struggling with.

My question: How do I rotate this list so everyone gets an equal shot at being at the top? I suspect I should use the ID field as a marker of some sort, but I'm not sure how. I would like the query to take the current ID, count down 10 sites, place the new marker there and list that site as #1. 24 hours later take that site, move down 10 more etc.

$list = fopen("/home/aspen2/public_html/include/list.php", "w");

fwrite($list, "<TABLE BORDER=1><TR><TH>SITE TITLE</TH><TH>SITE DESCRIPTION</TH><TH>IN</TH><TH>OUT</TH><TH>DATE</TH></TR>");

while ($row = mysql_fetch_array($sql_result)) {
fwrite($list, "<TR><TD><A HREF=\"$row[SITE_URL]\">$row[SITE_TITLE]</A></TD><TD>$row[SITE_DESC]</TD><TD>$row[SITE_IN]</TD><TD>$row[SITE_OUT]</TD><TD>$row[SITE_TIMESTAMP]</TD></TR>");
}

fwrite($list, "</TABLE>");

fclose($list);

If anyone has any ideas about the best way to rotate my list, please share them.

Thanks!
Rich S

[Anon]

1. How static is the list of links in your text file? And how
   many link are there in total? In other words, are you adding
   fewer than 10 links a day, and how frequently will each
   link get redisplayed?

2. You need to worry about the total number of links
   being an exact multiple of 10, in which case the same
   pattern will appear each time through the list.

3. As far as storing the "marker" you can just write a number
   to a separate file. Also, you might be better off reading
   the entire file into an array; this will be easier to program
   than to open the file, read and discard n-1 lines, then
   read and display 10 lines...

[Anon]

I created a table in a MySQL to store the links and I expect fewer than 10/day. From previous experience, I'm guessing the list will hover around 200 links.

I would make sure the number of links is not exactly divisible by 10, but do you think it would be more fair to use ORDER BY RAND() to pick a random row?

Thanks for the input!
Rich S

[Anon]

If you want 10 random rows out of the 200+ in your database, then use

SELECT * FROM your_table ORDER BY RAND() LIMIT 10;

The ORDER BY RAND() only works in 3.23 if I remember right.

---John Holmes...

[Anon]

Hey John, you're right about 3.23, which I don't have, so I ended up using the following code Garret posted in tips:

select id, id*0+rand() as randomizer from your_table order by randomizer;

Everything’s working fine now!

Thanks,
Rich S