setting expiry dates in php or mysql

Just asking for advice. when the client registers on the site, I send an email to their email address they provided for validation purposes, in the email they have a link and a validation code, I want to expire this code x-hours after registration, is it better to store the registration timestamp and in the prgramming count the x-hours, or should I also store the expiry 'DATETIME' ?
prowebinteractiveincAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Dave BaldwinFixer of ProblemsCommented:
Doesn't really matter, just pick a method.  I think I would do the arithmetic when they register so I can use a '<' comparison on the expiration DATETIME.
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
nanharbisonCommented:
In my experience, the timestamp is easier to manipulate in arithmetic, and you will be subtracting to see if the number of hours has expired.
0
Ray PaseurCommented:
This article has some ideas about how to use DATETIME values in PHP and MySQL.
http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/PHP/A_201-Handling-date-and-time-in-PHP-and-MySQL.html

I would store the ISO-8601 DATETIME string of the expiration in their row of the table.  I find this easier to read than an integer.  If they have three hours to confirm the registration, you might do something like this:
$expiry = date('c', strtotime('now + 3 hours));

Your confirmation query would look something like this:
UPDATE userTable SET confirmed='Y' WHERE key='$key' AND expiry >= NOW

If they fail to confirm, this sort of thing would remove the entry from the table.
DELETE FROM userTable WHERE confirmed<>'Y' AND expiry < NOW
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
PHP

From novice to tech pro — start learning today.