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', 'cfba1b170f201cb599000c894eb01cd4', '3.239.95.36', '1716634071', '1716634071', '/product_info.php/info/p74_Bluetenpollen--200-Gramm-.html')

[XT SQL Error]