Moving to -general (and please start a new thread instead of hijacking an existing one). On Thu, Nov 02, 2006 at 01:14:22PM -0500, louis gonzales wrote: > Hello all, > Is there an existing mechanism is postgresql that can automatically > increment/decrement on a daily basis w/out user interaction? The use > case I'm considering is where a student is in some type of contract with > an instructor of some sort, and that contract puts a time limit on the > student requiring her to pay a fee by a certain day. IF that day comes > to pass - or a certain number of days elapse - and that payment > requirement hasn't been met, I want to trigger a function. > > The one requirement I want to impose is, that no end user of the DB > application, needs to do anything to set the trigger, other than the > initialization of making the student of this type. > > An example would be: > Day1 - Application user(typically the instructor) creates a profile for > a new student - John Doe, which sets a 30 day time limit for John Doe to > pay $100.00 > Day2 -> Day31 - John Doe didn't make the payment > Day 31 - Trigger of event occurs when the instructor logs in. > > Basically on Day 1 when John Doe's profile was created, I want a > decrement counter to occur daily on his profile(some attribute/timer) > and nothing should happen until day 31 when he doesn't pay. While you could setup a cron job to decrement some counter every day, I think that's not the best approach. Instead, I'd run a query once a day that finds all students that are past-due and takes some kind of action. -- Jim Nasby jim@xxxxxxxxx EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
