(PHP 5)
mysqli::ping -- mysqli_ping — Pings a server connection, or tries to reconnect if the connection has gone down
Object oriented style (method):
Procedural style:
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.
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.
如果成功则返回 TRUE，失败则返回 FALSE。
Example #1 Object oriented style
<?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();
?>
Example #2 Procedural style
<?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);
?>
上例将输出：
Our connection is ok!