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# mysql_ping

(PHP 4 >= 4.3.0, PHP 5)

mysql_ping -- Ping a server connection or reconnect if there is no connection

## Description

bool mysql_ping ( [resource link_identifier] )

mysql_ping() 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. mysql_ping() returns `TRUE` if the connection to the server is working, otherwise `FALSE`.

範例 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_thread_id() and mysql_list_processes().

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