This does not work with mysqlnd and is marked as wontfix: https://bugs.php.net/bug.php?id=52561
(PHP 5, PHP 7, PHP 8)
mysqli::ping -- mysqli_ping — Pings a server connection, or tries to reconnect if the connection has gone down
Nesne yönelimli kullanım
Yordamsal kullanım
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.
Bilginize: 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.
bağlantı
Sadece yordamsal tarz: mysqli_connect() veya mysqli_init() işlevinden dönen bir mysqli nesnesi.
Eğer mysqli hata bildirimi etkinse (MYSQLI_REPORT_ERROR
)
ve istenen işlem başarısız olursa bir uyarı üretilir. Ek olarak, kip
MYSQLI_REPORT_STRICT
ise bunun yerine
mysqli_sql_exception istisnası oluşur.
Örnek 1 mysqli::ping() example
Nesne yönelimli kullanım
<?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();
?>
Yordamsal kullanım
<?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);
?>
Yukarıdaki örneklerin çıktısı:
Our connection is ok!
This does not work with mysqlnd and is marked as wontfix: https://bugs.php.net/bug.php?id=52561
As jay at grooveshark dot com very helpfully pointed out, the mysqlnd driver which is becoming pretty standard does not obey reconnect commands. If you have a DB wrapper class (which hopefully you do) you can implement your own version of ping() such as:
<?php
class db extends mysqli
{
private $db_host;
private $db_user;
private $db_pass;
private $db_name;
private $persistent;
public function __construct($db_host, $db_user, $db_pass, $db_name, $persistent = true)
{
$this->db_host = $db_host;
$this->db_user = $db_user;
$this->db_pass = $db_pass;
$this->db_name = $db_name;
$this->persistent = $persistent;
parent::init();
parent::options(MYSQLI_OPT_CONNECT_TIMEOUT, 1);
@parent::real_connect(($this->persistent ? 'p:' : '') . $this->db_host, $this->db_user, $this->db_pass, $this->db_name);
if ($this->connect_errno)
die("All DB servers down!\n");
}
public function ping()
{
@parent::query('SELECT LAST_INSERT_ID()');
if ($this->errno == 2006)
$this->__construct($this->db_host, $this->db_user, $this->db_pass, $this->db_name, $this->persistent);
}
...
}
$db = new db(DB_HOST, DB_USER, DB_PASS, DB_NAME);
// Some code that potentially takes a really long time to execute goes here
// Ping for safety to try to gracefully reconnect
$db->ping();
// Now we should be able to run queries again
$db->query('SELECT LAST_INSERT_ID()');
?>
If you wanted you could even put "$this->ping();" at the top of db::query() to avoid any explicit reconnection calls but I wouldn't recommend it due to the (slight) overhead of running the cheap "SELECT LAST_INSERT_ID()" query every time prior to running your real intended query. There are probably even cheaper queries to run in favor of "SELECT LAST_INSERT_ID()" but it was the first that came to mind and is cheap enough for most purposes since you shouldn't be calling ping() a whole bunch anyway.
The behaviour about the option mysqli.reconnect is default set to Off at Debian PHP Packages. So i would recommend to update the first line description about the recommendation at the option mysqli.reconnect. (practice note ;))