The dbx module is a database abstraction layer (db 'X', where 'X' is a supported database). The dbx functions allow you to access all supported databases using a single calling convention. The dbx-functions themselves do not interface directly to the databases, but interface to the modules that are used to support these databases.
To be able to use a database with the dbx-module, the module must be either linked or loaded into PHP, and the database module must be supported by the dbx-module. Currently, following databases are supported, but others will follow (soon, I hope :-):
FrontBase (available from PHP 4.1.0).
Sybase-CT (CVS only).
Documentation for adding additional database support to dbx can be found at http://www.guidance.nl/php/dbx/doc/.
In order to have these functions available, you must compile PHP with dbx support by using the --enable-dbx option and all options for the databases that will be used, e.g. for MySQL you must also specify --with-mysql=[DIR]. To get other supported databases to work with the dbx-module refer to their specific documentation.
This extension does not define any configuration directives.
There are two resource types used in the dbx module. The first one is the link-object for a database connection, the second a result-object which helds the result of a query.
These constants are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.