In order to have these functions available, you must compile PHP with MySQL support.
Although this MySQL extension is compatible with MySQL 4.1.0 and greater, it doesn't support the extra functionality that these versions provide. For that, use the MySQLi extension.
If you would like to install the mysql extension along with the mysqli extension you have to use the same client library to avoid any conflicts.
--with-mysql is enabled by
default. This default behavior may be disabled with the
--without-mysql configure option. If MySQL
is enabled without specifying the path to the MySQL install
DIR, PHP will use the bundled MySQL client libraries.
Users who run other applications that use MySQL (for
auth-mysql) should not use the
bundled library, but rather specify the path to MySQL's
install directory, like so:
--with-mysql=/path/to/mysql. This will
force PHP to use the client libraries installed by MySQL,
thus avoiding any conflicts.
MySQL is not enabled by default, nor is the MySQL library
bundled with PHP. Read this
FAQ for details on why. Use the
--with-mysql[=DIR] configure option to
include MySQL support. You can download headers
and libraries from http://www.mysql.com/.
The PHP MySQL extension is compiled into PHP.
MySQL is no longer enabled by default, so the
php_mysql.dll DLL must be enabled
php.ini. Also, PHP needs
access to the MySQL client library. A file named
libmysql.dll is included in the Windows
PHP distribution and in order for PHP to talk to MySQL this
file needs to be available to the Windows systems
PATH. See the FAQ titled
do I add my PHP directory to the
Windows" for information on how to do this.
libmysql.dll to the
Windows system directory also works (because the system
directory is by default in the system's
PATH), it's not recommended.
As with enabling any PHP extension (such as
php_mysql.dll), the PHP directive
should be set to the directory where the PHP extensions are
located. See also the
Windows Installation Instructions. An example
extension_dir value for PHP 5 is
If when starting the web server an error similar to the
"Unable to load dynamic
library './php_mysql.dll'", this
libmysql.dll cannot be found by the
Crashes and startup problems of PHP may be encountered when loading this extension in conjunction with the recode extension. See the recode extension for more information.
If you need charsets other than latin (default), you have to install external (not bundled) libmysql with compiled charset support.
The behaviour of these functions is affected by settings in
Table 21.4. MySQL Configuration Options
|mysql.trace_mode||"0"||PHP_INI_ALL||Available since PHP 4.3.0.|
|mysql.default_socket||NULL||PHP_INI_ALL||Available since PHP 4.0.1.|
|mysql.connect_timeout||"60"||PHP_INI_ALL||PHP_INI_SYSTEM in PHP <= 4.3.2. Available since PHP 4.3.0.|
For further details and definitions of the PHP_INI_* modes, see the configuration.changes.modes.
Here's a short explanation of the configuration directives.
Whether to allow persistent connections to MySQL.
The maximum number of persistent MySQL connections per process.
The maximum number of MySQL connections per process, including persistent connections.
Trace mode. When
enabled, warnings for table/index scans, non free result
sets, and SQL-Errors will be displayed. (Introduced in
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_PORT environment variable, the
mysql-tcp entry in
/etc/services or the compile-time
constant, in that order. Win32 will only use the
The default socket name to use when connecting to a local database server if no other socket name is specified.
The default server host to use when connecting to the database server if no other host is specified. Doesn't apply in SQL safe mode.
The default user name to use when connecting to the database server if no other name is specified. Doesn't apply in SQL safe mode.
The default password to use when connecting to the database server if no other password is specified. Doesn't apply in SQL safe mode.
Connect timeout in seconds. On Linux this timeout is also used for waiting for the first answer from the server.
There are two resource types used in the MySQL module. The first one is the link identifier for a database connection, the second a resource which holds the result of a query.