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', 'befd98498b3285272d5ea0e67f1fa5d5', '3.237.61.235', '1603442308', '1603442308', '/')

[XT SQL Error]