Q: integrating Databases in wordpress I was wondering if you guys can help me out.
We are developing a new forum component on our website. 
The forum is being created with PHP and MySQL and we want to integrate it with Wordpress.
The Problem is, that we don't want to create a whole new Register Forum because this will force the user to create TWO accounts (one for the site and one for the forum) and this is not user friendly.
So if you know a way to use the wordpress website user database with an outside database it will be great.
Another option is to create a whole new data base but then we force the users out of the commenting section on the Wordpress website. So if is there away to create a new Database that will allow them to use the same account for the website and for the forum that will be fantastic.
I hope someone here know how to merge the two data bases please help me out.
Thanks!

A: The Wordpress database schema is documented here.
http://codex.wordpress.org/Database_Description
In particular, the user table is here.
http://codex.wordpress.org/Database_Description#Table:_wp_users
Wordpress is open source, so you can look at its code to see how it authenticates itself to its database. Your application will need to do the same thing.
If you'll have your application on the same domain as the Wordpress system you're sharing users with, you may be able to figure out how to use the Wordpress user-authentication browser cookies to implement a single signon scheme.  
http://codex.wordpress.org/WordPress_Cookies
The Wordpress developers have created a forum system called bbpress.  You could consider using it or forking it. It has user-level integration.
http://bbpress.org/
Wordpress has its own stackExchange site at http://wordpress.stackexchange.com
