1366 - Incorrect integer value: '' for column 'customer_id' at row 1

insert into whos_online (customer_id, full_name, session_id, ip_address, time_entry, time_last_click, last_page_url) values ('', 'Guest', 'ep132n1b8p170n81ev44q0ijh5', '216.73.216.130', '1760925583', '1760925583', '/index.php?XTCsid=8d868f90067cee2351b383dfcfd75af4')

[XT SQL Error]