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', 'cp7d8hurr0jrmv5e5ddk0qdl80', '216.73.216.118', '1761579719', '1761579719', '/shop_content.php?XTCsid=a6fef95dcbdcf765a3c6baf6e1fe0e25&coID=4')

[XT SQL Error]