从站点A登录到站点B？

Question

There's one news-portal and its huge (site A). During production backwards, it has been even powered with some sort of a social networking stuff - not yet started, but about to start (soon site B).

Packed together looks great, but in some future there might be a lot of problems with maintaining the database, servers and stuff so I've been asked to separate it as I did. Site A goes on its own domain, site B also - databases are separated.

Now, I need to do the following: when user logs into site B (social site) and arrives to site A (portal) they should be instantly logged in there too (on a site A).

Any ideas how to do this - without duplicating entries to user tables?

EDIT:

Any other ideas instead of auth services? OpenId will just give us one user with 10 accounts, fakes and so on. How about cookie stuff or multi-database queries?

EDIT 2:

Well this is something hot.. unless its not April 1st joke and worth a try: http://www.shawnhogan.com/2005/12/cross-database-join-with-mysql.html

Answer 1

You can use OpenID .

OpenID is an open standard that describes how users can be authenticated in a decentralized manner, eliminating the need for services to provide their own ad hoc systems and allowing users to consolidate their digital identities.

If you want to share some profile information (eg posts or photos) without giving access to your login and password you can use OAuth .

Answer 2

See if my answer here is of any use.

It's pretty simple, and only requires user information to be kept on one side. Where you need some information on the non-database side, you can just pass that information there using values in a query string, alongside the encrypted string.

Answer 3

Can you believe this?

$DB->query("SELECT * FROM table..."); // works of course...

$DB->query("SELECT * FROM another_database.table..."); // WORKS ALSO!

This guy is a miracle:

http://www.shawnhogan.com/2005/12/cross-database-join-with-mysql.html

I don't believe it, so simple at the end!