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', 'ffa3d4cd7eee0b5a1e238de107938b53', '54.227.97.219', '1638975953', '1638975953', '/')

[XT SQL Error]