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', 'hlduurkju6j7urdda901bc4c04', '3.235.101.50', '1601419831', '1601419831', '/index.php?cat=c105_Das-Erste--Rote-Rosen.html&XTCsid=2d4qg7ftupcpr3opjmmv969b12')

[XT SQL Error]