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', 'k5ll4e4tn6165vpffavbpsj8e0', '18.191.97.68', '1746980229', '1746980229', '/xtshop/product_info.php?info=p404_.html')

[XT SQL Error]