Question

I am building a simple auction application. I need auctions to start and end at certain times. Should the page that displays the open auctions just run a query to find all auctions where current time is after the start time and before the end time? Or would it bet better to have a script that sets a “active” column to True? If this is the case would I have to have some type of cronjob setup?

Answer 1

No cron and no “active” column is required. Just list auctions using something like:

select *
from auctions
where
    start < now()
    and end > now()

When user is placing a bid use the following:

update auctions set
    bid = $bid,
    highest_bidder = $bidding_user_id
where
    id = $this_auction_id
    and start < now()
    and end > now()
    and bid < $bid

Then check if query has affected a row. If yes – bid is successful, current user is highest bidder. If no – bid is too low or auction has finished. You can figure out that later by fetching auction row again and checking bidder id.