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', 'p7uk6kv0753fbf23v1d0047ib2', '216.73.216.80', '1751324133', '1751324133', '/index.php?cat=c2_Decoration.html&XTCsid=b4e317ab79f3ee4221fe0e84cc3a81a4')

[XT SQL Error]