# dbx Functions

## Introduction

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.

> Note: This extension has been moved to the » PECL repository and is no longer bundled with PHP as of PHP 5.1.0.

## Requirements

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, the following databases are supported, but others will follow:

- FrontBase (available from PHP 4.1.0).
- Microsoft SQL Server
- MySQL
- ODBC
- PostgreSQL
- Sybase-CT (available from PHP 4.2.0).
- Oracle (oci8) (available from PHP 4.3.0).
- SQLite (PHP 5).

Documentation for adding additional database support to dbx can be found at » http://www.guidance.nl/php/dbx/doc/.

## Installation

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.

## Runtime Configuration

The behaviour of these functions is affected by settings in php.ini.

DBX Configuration Options
Name | Default | Changeable | Changelog
--- | --- | --- | ---
dbx.colnames_case | "unchanged" | PHP_INI_SYSTEM | Available since PHP 4.3.0. Removed in PHP 5.1.0.

For further details and definitions of the PHP_INI_* constants, see the php.ini directives.

Here's a short explanation of the configuration directives.

`dbx.colnames_case` string

  Columns names can be returned "unchanged" or converted to "uppercase" or "lowercase". This directive can be overridden with a flag to dbx_query().

## Resource Types

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 holds the result of a query.

## Predefined Constants

The constants below are defined by this extension, and will only be available when the extension has either been compiled into PHP or dynamically loaded at runtime.

`DBX_MYSQL` (integer)
`DBX_ODBC` (integer)
`DBX_PGSQL` (integer)
`DBX_MSSQL` (integer)
`DBX_FBSQL` (integer)
`DBX_OCI8` (integer) (available from PHP 4.3.0)
`DBX_SYBASECT` (integer)
`DBX_SQLITE` (integer) (PHP 5)
`DBX_PERSISTENT` (integer)
`DBX_RESULT_INFO` (integer)
`DBX_RESULT_INDEX` (integer)
`DBX_RESULT_ASSOC` (integer)
`DBX_RESULT_UNBUFFERED` (integer) (PHP 5)
`DBX_COLNAMES_UNCHANGED` (integer) (available from PHP 4.3.0)
`DBX_COLNAMES_UPPERCASE` (integer) (available from PHP 4.3.0)
`DBX_COLNAMES_LOWERCASE` (integer) (available from PHP 4.3.0)
`DBX_CMP_NATIVE` (integer)
`DBX_CMP_TEXT` (integer)
`DBX_CMP_NUMBER` (integer)
`DBX_CMP_ASC` (integer)
`DBX_CMP_DESC` (integer)

## Table of Contents

- dbx_close — Close an open connection/database
- dbx_compare — Compare two rows for sorting purposes
- dbx_connect — Open a connection/database
- dbx_error — Report the error message of the latest function call in the module
- dbx_escape_string — Escape a string so it can safely be used in an sql-statement
- dbx_fetch_row — Fetches rows from a query-result that had the DBX_RESULT_UNBUFFERED flag set
- dbx_query — Send a query and fetch all results (if any)
- dbx_sort — Sort a result from a dbx_query by a custom sort function