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', 'f4e19c81a98c5b77fa4a17780651975c', '34.229.24.100', '1563485498', '1563485498', '/shop_content.php/coID/3/content/Conditions-of-Use')

[XT SQL Error]