BetterPHP

My current code is:

[syntax=php]$sql = "SELECT * FROM juarez WHERE categoriesID = 4 ORDER BY RAND() LIMIT 1";[/syntax]

I need to seed the rand value to something that would make it get a new random row EACH hour, each day, and each week.
each sql query goes in different pages. I dont know where to start, can anybody help me please? I want to display a random row in a page in one page, a daily random in another and a weekly random in another. Please help me

Well the RAND() function accepts a seed parameter so you could probably combine it with the date functions

[syntax=sql]ORDER BY RAND(YEAR() * 1000 + WEEK())[/syntax]
for example

Remember that the use of the RAND() function like this is pretty slow for large tables though.