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', 'vtnufr9il14bked3d0kvi7su23', '216.73.216.80', '1751325031', '1751325031', '/shop_content.php?coID=7&XTCsid=705a3b68bece48fd9b67e5e30d623e8e')

[XT SQL Error]