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', 'eu8tldgle159h91bbv71kj9h75', '18.218.185.164', '1746784230', '1746784230', '/xtshop/product_info.php?info=p774_.html')

[XT SQL Error]