1366 - Incorrect integer value: '' for column `hollen`.`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, http_referer) values ('', 'Guest', 'h4lmtidtk3e9qc64bkohe00en7', '35.172.233.215', '1597179640', '1597179640', '/Produkte/Deutsch/Das-Feuerbohnenzelt::2222.html', 'Keiner/None')

[XT SQL Error]