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', 'mlskt1hhhmm3m3ch6np3cn8o16', '3.236.118.225', '1620908121', '1620908121', '/')

[XT SQL Error]