Return the current thread ID


This extension is deprecated as of PHP 5.5.0, and will be removed in the future. Instead, the MySQLi or PDO_MySQL extension should be used. See also MySQL: choosing an API guide and related FAQ for more information. Alternatives to this function include:

  • mysqli_thread_id


int mysql_thread_id ([ resource $link_identifier = NULL ] )

Retrieves the current thread ID. If the connection is lost, and a reconnect with mysql_ping is executed, the thread ID will change. This means only retrieve the thread ID when needed.



The MySQL connection. If the link identifier is not specified, the last link opened by mysql_connect is assumed. If no such link is found, it will try to create one as if mysql_connect was called with no arguments. If no connection is found or established, an E_WARNING level error is generated.

Return Values

The thread ID on success or FALSE on failure.


Example #1 mysql_thread_id example

$thread_id mysql_thread_id($link);
if (
printf("current thread id is %d\n"$thread_id);

The above example will output something similar to:

current thread id is 73

See Also

  • mysql_ping
  • mysql_list_processes