MySQLi
PHP Manual

mysqli::ping

mysqli_ping

(PHP 5, PHP 7)

mysqli::ping -- mysqli_pingPings a server connection, or tries to reconnect if the connection has gone down

说明

面向对象风格

bool mysqli::ping ( void )

过程化风格

bool mysqli_ping ( mysqli $link )

Checks whether the connection to the server is working. If it has gone down and global option mysqli.reconnect is enabled, an automatic reconnection is attempted.

Note: The php.ini setting mysqli.reconnect is ignored by the mysqlnd driver, so automatic reconnection is never attempted.

This function can be used by clients that remain idle for a long while, to check whether the server has closed the connection and reconnect if necessary.

参数

link

仅以过程化样式:由mysqli_connect()mysqli_init() 返回的链接标识。

返回值

成功时返回 TRUE, 或者在失败时返回 FALSE

范例

Example #1 mysqli::ping() example

面向对象风格

<?php
$mysqli 
= new mysqli("localhost""my_user""my_password""world");

/* check connection */
if ($mysqli->connect_errno) {
    
printf("Connect failed: %s\n"$mysqli->connect_error);
    exit();
}

/* check if server is alive */
if ($mysqli->ping()) {
    
printf ("Our connection is ok!\n");
} else {
    
printf ("Error: %s\n"$mysqli->error);
}

/* close connection */
$mysqli->close();
?>

过程化风格

<?php
$link 
mysqli_connect("localhost""my_user""my_password""world");

/* check connection */
if (mysqli_connect_errno()) {
    
printf("Connect failed: %s\n"mysqli_connect_error());
    exit();
}

/* check if server is alive */
if (mysqli_ping($link)) {
    
printf ("Our connection is ok!\n");
} else {
    
printf ("Error: %s\n"mysqli_error($link));
}

/* close connection */
mysqli_close($link);
?>

以上例程会输出:

Our connection is ok!

MySQLi
PHP Manual