MySQL Functions
PHP Manual

mysql_ping

(PHP 4 >= 4.3.0, PHP 5)

mysql_pingPing a server connection or reconnect if there is no connection

Description

bool mysql_ping ([ resource $link_identifier = NULL ] )

Checks whether or not the connection to the server is working. If it has gone down, an automatic reconnection is attempted. This function can be used by scripts that remain idle for a long while, to check whether or not the server has closed the connection and reconnect if necessary.

Note:

Automatic reconnection is disabled by default in versions of MySQL >= 5.0.3.

Parameters

link_identifier

The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect() is assumed. If no such link is found, it will try to create one as if mysql_connect() was called with no arguments. If no connection is found or established, an E_WARNING level error is generated.

Return Values

Returns TRUE if the connection to the server MySQL server is working, otherwise FALSE.

Examples

Example #1 A mysql_ping() example

<?php
set_time_limit
(0);

$conn mysql_connect('localhost''mysqluser''mypass');
$db   mysql_select_db('mydb');

/* Assuming this query will take a long time */
$result mysql_query($sql);
if (!
$result) {
    echo 
'Query #1 failed, exiting.';
    exit;
}

/* Make sure the connection is still alive, if not, try to reconnect */
if (!mysql_ping($conn)) {
    echo 
'Lost connection, exiting after query #1';
    exit;
}
mysql_free_result($result);

/* So the connection is still alive, let's run another query */
$result2 mysql_query($sql2);
?>

See Also


MySQL Functions
PHP Manual