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', 'pkt16e45e1h5dnooe8b6qj5tm4', '3.145.38.251', '1746772803', '1746772803', '/xtshop/product_info.php?info=p894_.html')

[XT SQL Error]