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', 'f309670046de6fb60f99af58c943b341', '18.209.66.87', '1711678936', '1711678936', '/index.php')

[XT SQL Error]