1366 - Incorrect integer value: '' for column `hbl_shop`.`whos_online`.`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', '1ln394p57mop16leqnf1vfqsc5', '216.73.216.50', '1781046287', '1781046287', '/shop_content.php?coID=2')

[XT SQL Error]