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', 'u7t8na1caf6oc7rfvffn8437d1', '18.232.51.69', '1586101588', '1586101588', '/', 'Keiner/None')

[XT SQL Error]