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', 'q8itria5k98hiurato2a1bkat4', '3.227.240.143', '1579500234', '1579500234', '/')

[XT SQL Error]