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', '4290787c0f6eb68223adf75829bc4760', '18.208.126.232', '1660853231', '1660853231', '/shop/index.php')

[XT SQL Error]