- 20.10.2 MySQL Improved Extension (Mysqli)
- 20.10.2.1 Examples
- 20.10.2.2 Overview
- 20.10.2.3 Installing/Configuring
- 20.10.2.4 The mysqli Extension and Persistent Connections
- 20.10.2.5 Predefined Constants
- 20.10.2.6 The MySQLi Extension Function Summary
- 20.10.2.7 The MySQLi class (MySQLi)
- 20.10.2.8 The MySQLi_STMT class (MySQLi_STMT)
- 20.10.2.9 The MySQLi_Result class (MySQLi_Result)
- 20.10.2.10 The MySQLi_Driver class (MySQLi_Driver)
- 20.10.2.11 The MySQLi_Warning class (MySQLi_Warning)
- 20.10.2.12 Aliases and deprecated Mysqli Functions
[+/-]
Copyright 1997-2008 the PHP Documentation Group.
Copyright 1997-2008 the PHP Documentation Group.
In order to have these functions available, you must compile PHP with support for the mysqli extension.
Note
The mysqli extension is designed to work with MySQL version 4.1.13 or newer, or 5.0.7 or newer. For previous versions, please see the MySQL extension documentation.
Copyright 1997-2008 the PHP Documentation Group.
As of PHP 5.0, MySQL support is no longer enabled by default with the standard PHP distributions. This means PHP needs to be explicitly configured to take advantage of the MySQL extensions.
The common Unix distributions include binary versions of PHP that can be installed. Although these binary versions are typically built with support for MySQL extensions enabled, the extension libraries themselves may need to be installed using an additional package. Check the package manager than comes with your chosen distribution for availability.
Unless your Unix distribution comes with a binary package of PHP
with the mysqli extension available, you will
need to build PHP from source code. 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.
To ensure that the mysqli extension for PHP
is enabled, you will need to configure the PHP source code to
use mysqli. This is achieved by running the
configure script with the option
--with-mysqli=mysql_config_path/mysql_config,
prior to building PHP. This will enable
mysqli and it will use the MySQL Client
Library (libmysql) to communicate with the MySQL Server.
Note
The mysql_config_path represents the
location of the mysql_config program that
comes with MySQL Server.
With versions of PHP 5.3 and newer, you can alternatively use
the new MySQL Native Driver with mysqli. This
gives a number of benefits over using libmysql.
To use MySQL Native Driver with mysqli you
need to configure the PHP source code using the
--with-mysqli=mysqlnd option, prior to building
PHP.
This is the recommended option, as using the MySQL Native Driver 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.
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 (libmysql),
while configuring the mysqli extension to use
the MySQL Native Driver. However, all permutations of extension
and client library are possible.
The following example builds the MySQL extension to use the
MySQL Client Library, and the mysqli and PDO
MYSQL extensions to use the MySQL Native Driver:
Copyright 1997-2008 the PHP Documentation Group.
On Windows, PHP is most commonly installed using the binary
installer. Once PHP has been installed, some configuration is
required to enable mysqli and specify the
client library you want it to use.
As mentioned earlier, 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.
On Windows, for PHP versions 5.3 and newer, the
mysqli extension uses the MySQL Native
Driver by default. This means you don't need to worry
about configuring access to libmysql.dll,
you just need to make sure the extension is enabled in the
php.ini file.
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.
Copyright 1997-2008 the PHP Documentation Group.
The behaviour of these functions is affected by settings in php.ini.
Table 20.7. MySQLi Configuration Options
| Name | Default | Changeable | Changelog |
|---|---|---|---|
| mysqli.allow_persistent | "1" | PHP_INI_SYSTEM | Available since PHP 5.3.0. |
| mysqli.max_persistent | "-1" | PHP_INI_SYSTEM | Available since PHP 5.3.0. |
| mysqli.max_links | "-1" | PHP_INI_SYSTEM | Available since PHP 5.0.0. |
| mysqli.default_port | "3306" | PHP_INI_ALL | Available since PHP 5.0.0. |
| mysqli.default_socket | NULL | PHP_INI_ALL | Available since PHP 5.0.0. |
| mysqli.default_host | NULL | PHP_INI_ALL | Available since PHP 5.0.0. |
| mysqli.default_user | NULL | PHP_INI_ALL | Available since PHP 5.0.0. |
| mysqli.default_pw | NULL | PHP_INI_ALL | Available since PHP 5.0.0. |
| mysqli.reconnect | "0" | PHP_INI_SYSTEM | Available since PHP 4.3.5. |
| mysqli.allow_local_infile | "1" | PHP_INI_SYSTEM | Available since PHP 5.2.4. |
| mysqli.cache_size | "2000" | PHP_INI_SYSTEM | Available since PHP 5.3.0. |
For further details and definitions of the above PHP_INI_* constants, see the chapter on configuration changes.
Here's a short explanation of the configuration directives.
-
mysqli.allow_persistentinteger Enable the ability to create persistent connections using
mysqli_connect.-
mysqli.max_persistentinteger Maximum of persistent connections that can be made. Set to 0 for unlimited.
-
mysqli.max_linksinteger The maximum number of MySQL connections per process.
-
mysqli.default_portinteger The default TCP port number to use when connecting to the database server if no other port is specified. If no default is specified, the port will be obtained from the
MYSQL_TCP_PORTenvironment variable, themysql-tcpentry in/etc/servicesor the compile-timeMYSQL_PORTconstant, in that order. Win32 will only use theMYSQL_PORTconstant.-
mysqli.default_socketstring The default socket name to use when connecting to a local database server if no other socket name is specified.
-
mysqli.default_hoststring The default server host to use when connecting to the database server if no other host is specified. Doesn't apply in safe mode.
-
mysqli.default_userstring The default user name to use when connecting to the database server if no other name is specified. Doesn't apply in safe mode.
-
mysqli.default_pwstring The default password to use when connecting to the database server if no other password is specified. Doesn't apply in safe mode.
-
mysqli.reconnectinteger Automatically reconnect if the connection was lost.
-
mysqli.allow_local_infileinteger -
mysqli.cache_sizeinteger Available only with mysqlnd.
Copyright 1997-2008 the PHP Documentation Group.
This extension has no resource types defined.
User Comments
Add your own comment.