PHP & SQL online auction site question

Fat

I am building an online auction site using php and sql. I am having some trouble figuring out an efficient way to have auctions end themselves. That is, after a specific time period the auction would be set to "closed" and no more bids allowed.

I'm looking for some pseudo suggestions on how I can do this.

At current I have a sql table field that has "Open/Closed" status, which I query throughout the auction site. In terms of auction duration, it's simply 3, 5, or 7 days and stored in the field auction_duration. What I was thinking of doing is upon the auctions creation using timestamp and now() and store that value in a field called auction_start. From there I can create a function and stick it at the top of my php scripts to subtract a formated auction_duration from the current timestamp, from there comparing the resulting value with the auction_start value. If the auction value is less than or equal to 0 then the auction is over.

What I don't like about this is that it means I have to have that function included all over my site. Is this on the right track on how to do this or is there a better way?

Thanks a bunch for your time,
Chris

cgraz

Just add 3 days or whatever to now() in it's own field called auction_close

in pseudo, now() + 3 days and have it look something like this: 2002/12/26 5:45:21

Then

if (current date >= to closing date) {
// all bids are closed

} else {
// bidding is still open
}

If you have a place hwere people can view current auctions. For ex:

Auction Item Price Auction Open Auction Close
Auction Item2 Price Auction Open Auction Close

(or using ebay as an example: http://listings.ebaymotors.com/aw/plistings/list/category6357/index.html?from=R4)

and you don't want to display closed items

select * from yourtable where currentdate <= auction_close

Then if someone has that particular item bookmarked (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1875505463&category=5336)

And you don't want to allow them to bid, you just run that above if statement. If all bids are closed,
just display text that says bidding is closed and don't allow them to bid.

If it's open, just display as normal.

I've never done this before, this is just the first way that popped into my mind. Does this help?

Cgraz