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', 'rng194bf5porjd1rlq5a9ka4b3', '3.236.15.142', '1594641599', '1594641599', '/Sitemap:_:8.html', 'Keiner/None')

[XT SQL Error]