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', 'asv6grqqnatv71e2vq4r3hk7n4', '216.73.216.80', '1751320260', '1751320260', '/index.php?XTCsid=ee72fd127966305e536831aa3802aefb')

[XT SQL Error]