Recommendation / Marrying Up Algorithm in PHP?

Is there something that has been already developed and is Open Sourced?

I'd like to develop a site that is like:

http://www.swap.com/

What I envisage is that a USER A puts in what they have, dvd's, book's, cd's, etc.

USER A then puts in what they are looking开发者_开发知识库 for themselves.

The system then does a check against all the users. It finds that USER B is requesting items thats in USER A's inventory.

So USER A can swap item X for USER B item X.

I just don't want to try (operative word here being try) to reinvent the wheel if its kinda been done before.

Thanks

Hmm... not too hard to code, as dionyziz said it's a very simple SQL query. Since you don't want to recreate anything, I suggest looking into inventory scripts. These are scripts generally used to keep track of a store or business's inventory of items for sale, however if you find one that's designed to manage multiple "stores", then each "user" could be a store with their own "inventory".

A quick search for "open source php inventory script" turned up http://www.phpwares.com/

Not sure if it supports multiple "stores", though.

This can easily be done with an SQL query. SELECT from your whole userbase those items who match your currently logged in user's requests.