The mysqli extension was introduced with PHP version
5.0.0. The MySQL Native Driver was included in PHP version 5.3.0.
The common Unix distributions include binary versions of PHP that can be installed. Although these binary versions are typically built with support for the MySQL extensions, the extension libraries themselves may need to be installed using an additional package. Check the package manager that comes with your chosen distribution for availability.
For example, on Ubuntu the php5-mysql package installs
the ext/mysql, ext/mysqli, and pdo_mysql PHP extensions. On CentOS,
the php-mysql package also installs these three
PHP extensions.
Alternatively, you can compile this extension yourself. Building PHP from source allows you to specify the MySQL extensions you want to use, as well as your choice of client library for each extension.
The MySQL Native Driver is the recommended client library option, as it results in improved performance and gives access to features not available when using the MySQL Client Library. Refer to What is PHP's MySQL Native Driver? for a brief overview of the advantages of MySQL Native Driver.
The /path/to/mysql_config represents the location of
the mysql_config program that comes with MySQL
Server.
| PHP Version | Default | Configure Options: mysqlnd | Configure Options: libmysqlclient |
Changelog |
|---|---|---|---|---|
| 5.4.x and above | mysqlnd | --with-mysqli | --with-mysqli=/path/to/mysql_config | mysqlnd is the default |
| 5.3.x | libmysqlclient | --with-mysqli=mysqlnd | --with-mysqli=/path/to/mysql_config | mysqlnd is supported |
| 5.0.x, 5.1.x, 5.2.x | libmysqlclient | Not Available | --with-mysqli=/path/to/mysql_config | mysqlnd is not supported |
Note that it is possible to freely mix MySQL extensions and client
libraries. For example, it is possible to enable the MySQL extension
to use the MySQL Client Library (libmysqlclient), while configuring the
mysqli extension to use the MySQL Native Driver.
However, all permutations of extension and client library are
possible.
On Windows, PHP is most commonly installed using the binary installer.
On Windows, for PHP versions 5.3 and newer, the
mysqli extension is enabled and
uses the MySQL Native Driver by default. This means you don't need to
worry about configuring access
to libmysql.dll.
On these old unsupported PHP versions (PHP 5.2 reached EOL on '6 Jan 2011'),
additional configuration procedures are
required to enable mysqli and specify the client
library you want it to use.
The mysqli extension is not
enabled by default, so the php_mysqli.dll DLL
must be enabled inside of php.ini. In order to do this you need to
find the php.ini file (typically located in
c:\php), and make sure you remove the comment
(semi-colon) from the start of the line
extension=php_mysqli.dll, in the section marked
[PHP_MYSQLI].
Also, if you want to use the MySQL Client Library with
mysqli, you need to make sure PHP can access the
client library file. The MySQL Client Library is included as a file
named libmysql.dll in the Windows PHP
distribution. This file needs to be available in the Windows system's
PATH environment variable, so that it can be
successfully loaded. See the FAQ titled
"How do I add my PHP
directory to the PATH on Windows" for information on how to do
this. Copying libmysql.dll to the Windows system
directory (typically c:\Windows\system) also
works, as the system directory is by default in the system's
PATH. However, this practice is strongly discouraged.
As with enabling any PHP extension (such as
php_mysqli.dll), the PHP directive
extension_dir should be set
to the directory where the PHP extensions are located. See also the
Manual Windows Installation
Instructions. An example extension_dir
value for PHP 5 is c:\php\ext.
Note:
If when starting the web server an error similar to the following occurs:
"Unable to load dynamic library './php_mysqli.dll'", this is because php_mysqli.dll and/or libmysql.dll cannot be found by the system.