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', 'r62t7hjk23bhc1acimq9gfvmj5', '216.73.217.113', '1782126713', '1782126713', '/xtshop/product_info.php?info=p1119_.html')

[XT SQL Error]