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', '89ho0o0ad29jfmloamhk2ost67', '18.97.14.82', '1747097420', '1747097420', '/xtshop/popup_content.php?coID=1')

[XT SQL Error]