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', 'ga19qj9jgg45o8n50iq3g7kdn6', '18.117.111.63', '1746782990', '1746782990', '/xtshop/index.php?cat=c103_.html')

[XT SQL Error]