How auction websites work? [closed]

开发者_如何转开发 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 11 years ago.

I simply wonder how auction websites lite ebay work?

The main thing I wonder about is how the technical part of the auction works when placing bids.

For example, what happens if two people place a bid exactly at the same second?

What programming lang is used, and preferred? (I preferr PHP if it works good)

Does auction sites require server cron jobs in order to detect ending times of bids?

I would appreciate a good article on this.

Also, in terms of safety, what should one watch out for when making an auction site compared to making a regular classifieds website (which I have made already)?

Thanks

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Not really a question for here I guess, but here's the answer.

First come first go, the page that loads the fastest will get the bid and the other will be notified that his/her bid is too low.

Programming language doesn't mather, ASP, PHP, everything will work if you programm it the right way. Cronjobs are not needed, if there's a datetime field in the database you are able to check the current time against the end time and thus allowing a bid or not (and for viewing all auctions this is used to display an auction or not). However, you could use a cronjob that scans your database for ended auctions and perhaps archive them in another table to keep your active auction database clean (same for all bid-logs etc)

Im not sure what you WOULDN'T do for safety,.. if your sending peoples data across the website, you might consider an SSL certificate to secure their personal details. And ofcourse all default security like checking values, integers, escaping database values etc.

Also, there are a lot of sites making use of jQuery/javascript right now. This way you can see the auction live. It's nothing more than having a javascript function running on an interval making a request to a PHP file which fetches the current bid/bid end and perhaps other information and displaying it every X second(s) to the screen.