1366 - Incorrect integer value: '' for column `agentur`.`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', '6vrl11p9r0v9b2ttv0c8rm0c40', '3.235.101.50', '1601423138', '1601423138', '/index.php?cat=c93_Markus-Lanz---Januar-2013.html&XTCsid=l56nbturorq4sho45n10a33330')

[XT SQL Error]