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', 'sift66jbkkmju0re0vt2aepn30', '3.234.208.66', '1582532164', '1582532164', '/shop/index.php')

[XT SQL Error]