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', 'i9r5q680f6kqoco3kgl5m789l2', '216.73.216.130', '1760836328', '1760836328', '/shop_content.php?XTCsid=0045c82a20eb26c176bef1fc0ba16df3&coID=2')

[XT SQL Error]