(PHP 4 = 4.3.0) mysql_thread_id() returns the current thread ID. If the connection is lost and you reconnect with mysql_ping(), the thread ID will change. This means you should not get the thread ID and store it for later. You should get it when you need it. δΎ‹ 1 mysql_thread_id() example The above example would produce the following output: See also: mysql_ping(), mysql_list_processes().