Establishes a persistent connection to a MySQL server.
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'.
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'
The username. Default value is the name of the user that owns the server process.
The password. Default value is an empty password.
The client_flags parameter can be a combination
of the following constants:
LOAD DATA LOCAL handling),
|4.3.0||Added the client_flags parameter.|
|3.0.10||Added support for ":/path/to/socket" with server.|
|3.0.0||Added support for ":port" with server.|
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.
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.
You can suppress the error message on failure by prepending a @ to the function name.