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', 'h3jtf2d8qc5pnkrtb3aoaujkp4', '18.207.106.142', '1600701094', '1600701094', '/index.php?cat=c19_Hotel-Atlantic-Kempinski-Hamburg---Generalueberholt.html&XTCsid=2d4qg7ftupcpr3opjmmv969b12')

[XT SQL Error]