Can any one suggest me a good framework for working with SQL Server or Oracle.
Have you looked at the SQL Server and Oracle extensions for PHP? This would be the obvious way of working with SQL Server and Oracle from PHP.
You could also try the PDO extension for PHP. It provides a consistent interface for working with different database engines. It has support for both SQL Server and Oracle.
If you are looking for a way to connect to, and modify your database with PHP, something I use and recommend is the ADOdb library ( http://adodb.sourceforge.net/ )
It allows you to abstract the database calls and use common functions for your application that are not database specific. I like this approach as I work on multiple projects that have different database requirements and it allows my code to be more portable, meaning no matter what database I am using, the code never has to change if I want to reuse it.
It also helps with code consistency across projects, and over time will help you maintain those apps more efficiently as they using a "standard" way of doing things.