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', '422927bdea4a76365a5c3149a155449b', '216.73.216.123', '1769422895', '1769422895', '/')

[XT SQL Error]