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', 'ae72c956c8bb5a7d8375325ce4509b5b', '18.191.240.243', '1714136476', '1714136476', '/redirect.php?action=product&id=12')

[XT SQL Error]