1366 - Incorrect integer value: '' for column `CP_as15`.`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', '6u1g7uqgnu1k2c4q08if561ba2', '18.118.20.13', '1738999902', '1738999902', '/index.php?XTCsid=nj57khd41hu8ciniagj0kmvlc3&cat=c1023_Werkzeugakku-LED-Lampen.html')

[XT SQL Error]