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', '35c6ca60b5fba1067094d3a216fa9c63', '18.119.107.161', '1713904426', '1713904426', '/redirect.php?action=product&id=6')

[XT SQL Error]