1366 - Incorrect integer value: '' for column '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', '1699d4a6ba270c00428ccfc09b564658', '3.239.95.36', '1716638222', '1716638222', '/index.php/cat/c3_andere-Bienenprodukte.html')

[XT SQL Error]