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', '27d9789d1fa753f2c5b386803f1c69e9', '18.116.88.132', '1736922994', '1736922994', '/shop/index.php')

[XT SQL Error]