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', 'bbc7f2542230642efdc2537e8e400c0d', '216.73.216.251', '1752521680', '1752521680', '/index.php/language/de/refID/2')

[XT SQL Error]