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', '539fd7c0378adea0e0a56184e7e19628', '216.73.216.3', '1766025854', '1766025854', '/shop_content.php/language/de/coID/3/content/Unsere-AGB')

[XT SQL Error]