mysqli::$thread_id

(PHP 5, PHP 7)

Returns the thread ID for the current connection

int mysqli_thread_id ( mysqli $link )

Object oriented style

int $mysqli->thread_id;

Procedural style

The mysqli_thread_id() function returns the thread ID for the current connection which can then be killed using the mysqli_kill() function. If the connection is lost and you reconnect with mysqli_ping(), the thread ID will be other. Therefore you should get the thread ID only when you need it.

Note:

The thread ID is assigned on a connection-by-connection basis. Hence, if the connection is broken and then re-established a new thread ID will be assigned.

To kill a running query you can use the SQL command KILL QUERY processid.

Parameters:

link

Procedural style only: A link identifier returned by mysqli_connect() or mysqli_init()

Returns:

Returns the Thread ID for the current connection.

Examples:

$mysqli->thread_id example

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();
}

/* determine our thread id */
$thread_id = $mysqli->thread_id;

/* Kill connection */
$mysqli->kill($thread_id);

/* This should produce an error */
if (!$mysqli->query("CREATE TABLE myCity LIKE City")) {
    printf("Error: %s\n", $mysqli->error);
    exit;
}

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

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();
}

/* determine our thread id */
$thread_id = mysqli_thread_id($link);

/* Kill connection */
mysqli_kill($link, $thread_id);

/* This should produce an error */
if (!mysqli_query($link, "CREATE TABLE myCity LIKE City")) {
    printf("Error: %s\n", mysqli_error($link));
    exit;
}

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

The above examples will output:

Error: MySQL server has gone away