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', 'nnisebefdk4uvus0fjo4gv0fe0', '18.118.207.174', '1746762752', '1746762752', '/xtshop/index.php?cat=c16_.html')

[XT SQL Error]