You could also try the database abstraction layer I use on my site. T'was originally wirtten by Frank Kromman (I added the MySQL, PostgreSQL, error debugging support, and API documentation). You'd need to write the Oracle extension, but that wouldn't be all that hard. The layer currently supports:
- MySQL
- PostgreSQL
- Frontbase
- MS SQL Server
- all db's covered by the ODBC functions
You can download it from: http://www.mithril.ca/code/php/lib_db_abstraction.php
HTH.
-geoff