How can I connect to all types of databases using php?

I have a little question. I am looking for a mode to connect 开发者_开发百科to all types of databases using php and I don't find anything usefull. For example I am developing a platform and it will be on all kinds of databases like Mysql or PostgreSQL or others.

PHP's PDO extension has many drivers though some (Oracle for example) are marked experimental.

The database adapter class in Zend Framework does a particularly good job at abstracting connection details.

You could also try Doctrine

Use and abstract database library such as http://adodb.sourceforge.net/

Database protocols don't have a standard like HTTP does. To create something like this, you would need to create an implementation for every database. Given the number and diversity of them, this would be very difficult.