PHP Manual
MySQL Functions
Open a persistent connection to a MySQL server

mysql_pconnect

(PHP 4, PHP 5)

mysql_pconnect — Open a persistent connection to a MySQL server

Warning

This extension was deprecated in PHP 5.5.0, and it was removed in PHP 7.0.0. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide. Alternatives to this function include:

mysqli_connect() with p: host prefix
PDO::__construct() with PDO::ATTR_PERSISTENT as a driver option

Description

mysql_pconnect(
    string $server = ini_get("mysql.default_host"),
    string $username = ini_get("mysql.default_user"),
    string $password = ini_get("mysql.default_password"),
    int $client_flags = 0
): resource

Establishes a persistent connection to a MySQL server.

mysql_pconnect() acts very much like mysql_connect() with two major differences.

First, when connecting, the function would first try to find a (persistent) link that's already open with the same host, username and password. If one is found, an identifier for it will be returned instead of opening a new connection.

Second, the connection to the SQL server will not be closed when the execution of the script ends. Instead, the link will remain open for future use (mysql_close() will not close links established by mysql_pconnect()).

This type of link is therefore called 'persistent'.

Parameters

server

The MySQL server. It can also include a port number. e.g. "hostname:port" or a path to a local socket e.g. ":/path/to/socket" for the localhost.

If the PHP directive mysql.default_host is undefined (default), then the default value is 'localhost:3306'

username

The username. Default value is the name of the user that owns the server process.

password

The password. Default value is an empty password.

client_flags

The client_flags parameter can be a combination of the following constants: 128 (enable LOAD DATA LOCAL handling), MYSQL_CLIENT_SSL, MYSQL_CLIENT_COMPRESS, MYSQL_CLIENT_IGNORE_SPACE or MYSQL_CLIENT_INTERACTIVE.

Return Values

Returns a MySQL persistent link identifier on success, or false on failure.

Notes

Note:
Note, that these kind of links only work if you are using a module version of PHP. See the Persistent Database Connections section for more information.

Warning

Using persistent connections can require a bit of tuning of your Apache and MySQL configurations to ensure that you do not exceed the number of connections allowed by MySQL.