# mysqli::$thread_id

# mysqli_thread_id

(PHP 5, PHP 7)

mysqli::$thread_id -- mysqli_thread_id — Returns the thread ID for the current connection

### Description

Object oriented style

int $mysqli->thread_id;

Procedural style

mysqli_thread_id ( mysqli `$link` ) : int

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()

### Return Values

Returns the Thread ID for the current connection.

### Examples

Example #1 $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

### See Also

- mysqli_kill() - Asks the server to kill a MySQL thread