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', 'f0g5of0age5sj8705fksdb93o0', '3.138.170.222', '1746762690', '1746762690', '/xtshop/index.php?cat=c43_.html')

[XT SQL Error]