PHP is a server-side, HTML-embedded scripting language that may be used to create dynamic Web pages. It is available for most operating systems and Web servers, and can access most common databases, including MySQL. PHP may be run as a separate program or compiled as a module for use with a Web server.
PHP provides several different MySQL API extensions:
The PHP documentation assumes PHP 7 and higher is used; functionality specific to PHP 5 and below is not documented.
MySQLi: Stands for “MySQL, Improved”; this extension is available as of PHP 5.0.0. It is intended for use with MySQL 4.1.1 and later. This extension fully supports the authentication protocol used in MySQL 5.0, as well as the Prepared Statements and Multiple Statements APIs. In addition, this extension provides an advanced, object-oriented programming interface.
PDO_MySQL: Not its own API, but instead it's a MySQL driver for the PHP database abstraction layer PDO (PHP Data Objects). The PDO MySQL driver sits in the layer below PDO itself, and provides MySQL-specific functionality. This extension is available as of PHP 5.1.0.
MySQL: Available for PHP versions 4 and 5, this extension is intended for use with MySQL versions prior to MySQL 4.1. This extension does not support the improved authentication protocol used in MySQL 4.1, nor does it support prepared statements or multiple statements. To use this extension with MySQL 4.1, you will likely configure the MySQL server to set the
old_passwordssystem variable to 1 (see Client does not support authentication protocol).Warning
This extension was removed from PHP 5.5.0. All users must migrate to either
mysql_xdevapi. For further information, see Choosing a MySQL Library.
This documentation, and other publications, sometimes uses the
Connector/PHP. This term refers to the
full set of MySQL related functionality in PHP, which includes
the APIs that are described in the preceding discussion, along
core library and all of its plugins.
The PHP distribution and documentation are available from the PHP website.