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', 'tq06u76jv7t16ikqqid01q5so5', '35.175.248.25', '1558962614', '1558962614', '/')

[XT SQL Error]