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', '2c4hjjqindcmr1jrl6lkj0f2e2', '216.73.216.141', '1751418809', '1751418809', '/product_info.php?info=p11_Fan-for-decorations.html&XTCsid=7c604026da355cfd6a094c68b431572d')

[XT SQL Error]