1366 - Incorrect integer value: '' for column `mapshopatlogis`.`whos_online`.`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', '31699bd18d977352d87bc868ebdd0f80', '216.73.216.58', '1770679879', '1770679879', '/product_info.php/info/p439_Reliefkarten-Konfigurator.html?refID=2')

[XT SQL Error]