Select Data from multiple databases?

How can i access in t开发者_StackOverflow中文版wo different databases at the same time, i mean can i implement a search from database1 and save for example the id or another information to a database2?

If you have a user account that can access both databases, just prefix the database name:

SELECT database1.table1, database2.table2.....

as far as I know, you can even do JOINs, although I don't know about possible performance implications.

If you do not have a mySQL account that can access both databases, it's not possible.

Yes. PHP has a few MySQL extensions. However, if you're just getting started, look at the MySQL functions for this. Specifically mysql_connect() and mysql_select_db() could be used to create separate connections to different databases or switch between them on the same connection.