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', 'gcuu86lparb5qg6rglsl3kl906', '216.73.216.141', '1751428144', '1751428144', '/shop_content.php?coID=8&XTCsid=d0fb6f95a363340d124d7dc76e615e44')

[XT SQL Error]