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PHP mysqli: thread_id() function

mysqli_thread_id() function / mysqli::$thread_id

The mysqli_thread_id() function / mysqli::$thread_id returns the thread ID for the current connection. The connection can then be killed with the mysqli_kill() function.

Note: If the connection is broken and you reconnect, the thread ID will be changed. Therefore; get the thread ID only when you need it.

Syntax:

Object oriented style

int $mysqli->thread_id;

Procedural style

int mysqli_thread_id ( mysqli $link )

Parameter:

Name Description Required/Optional
link A link identifier returned by mysqli_connect() or mysqli_init() Required for procedural style only and Optional for Object oriented style

Usage: Procedural style

mysqli_thread_id(connection);

Parameter:

Name Description Required/Optional
connection Specifies the MySQL connection to use. Required

Return value:

Returns the Thread ID for the current connection.

Version: PHP 5, PHP 7

Example of object oriented style:

<?php
$mysqli = new mysqli("localhost", "user1", "datasoft123", "hr");

/* 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();
?>

Output:

Error: MySQL server has gone away

Example of the Procedural style

<?php
$link = mysqli_connect("localhost", "user1", "datasoft123", "hr");

/* 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);
?>

Output:

Error: MySQL server has gone away

Example:

<?php
$con=mysqli_connect("localhost","user1","datasoft123","hr");
// Check connection
if (mysqli_connect_errno())
  {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
  }

// Get thread id
$t_id=mysqli_thread_id($con);

// Kill connection
mysqli_kill($con,$t_id);
?>

See also

PHP Function Reference

Previous: store_result
Next: thread_safe



PHP: Tips of the Day

var_export(): var_export() dumps a PHP parseable representation of the item.

You can pass true as the second parameter to return the contents into a variable.

Example:

<?php
$myarray = [ "PHP", "Tips" ];
$mystring = "PHP Tips";
$myint = 28;

var_export($myarray);
var_export($mystring);
var_export($myint);
?>

Output:

array (
  0 => 'PHP',
  1 => 'Tips',
)'PHP Tips'28

To put the content into a variable, you can do this:

$array_export = var_export($myarray, true);
$string_export = var_export($mystring, true);
$int_export = var_export($myint, 1); // any `Truthy` value

After that, you can output it like this:

printf('$myarray = %s; %s', $array_export, PHP_EOL);
printf('$mystring = %s; %s', $string_export, PHP_EOL);
printf('$myint = %s; %s', $int_export, PHP_EOL);

Example:

<?php
$myarray = [ "PHP", "Tips" ];
$mystring = "PHP Tips";
$myint = 28;
$array_export = var_export($myarray, true);
$string_export = var_export($mystring, true);
$int_export = var_export($myint, 1);
printf('$myarray = %s; %s', $array_export, PHP_EOL);
printf('$mystring = %s; %s', $string_export, PHP_EOL);
printf('$myint = %s; %s', $int_export, PHP_EOL);
?>

This will produce the following output:

Output:

$myarray = array (
  0 => 'PHP',
  1 => 'Tips',
);
$mystring = 'PHP Tips';
$myint = 28;