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', '3v439r5j91klnvq2802n1mbks0', '216.73.216.119', '1757950640', '1757950640', '/xtshop/create_account.php')

[XT SQL Error]