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', 'ej0j00me6nssf72a9frqr0qdp0', '216.73.216.113', '1752883991', '1752883991', '/product_info.php?info=p5_Large-Garland-33-feet.html&XTCsid=0308d34f52db367f9a7068f51bec2a23')

[XT SQL Error]