The behaviour of these functions is affected by settings in php.ini.
| 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 preceding PHP_INI_* constants, see the chapter on configuration changes.
Here's a short explanation of the configuration directives.
Enable the ability to create persistent connections using mysqli_connect().
Maximum of persistent connections that can be made. Set to 0 for unlimited.
The maximum number of MySQL connections per process.
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 MYSQL_PORT constant, in that order. Win32 will only use the MYSQL_PORT constant.
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 safe mode.
The default user name to use when connecting to the database server if no other name is specified. Doesn't apply in safe mode.
The default password to use when connecting to the database server if no other password is specified. Doesn't apply in safe mode.
Automatically reconnect if the connection was lost.
Available only with mysqlnd.
Users cannot set MYSQL_OPT_READ_TIMEOUT through an API call or runtime configuration setting. Note that if it were possible there would be differences between how libmysql and streams would interpret the value of MYSQL_OPT_READ_TIMEOUT.