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', 'b0o8rhq9pbqheb86pifdo3tk43', '216.73.216.113', '1775369867', '1775369867', '/index.php?XTCsid=cf4692a620e8efffd6d37fae4c1bd5ad')

[XT SQL Error]