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', 'mqfjlkdsh7964c9i0pl9d0bkf3', '3.235.101.50', '1601421734', '1601421734', '/index.php?cat=c58_Das-Erste--Tatort---Dinge--die-noch-zu-tun-sind----Blaubeerblau.html&XTCsid=2d4qg7ftupcpr3opjmmv969b12')

[XT SQL Error]