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', 'a0028c071613c51064bf7e664ff014ce', '44.206.227.65', '1711673891', '1711673891', '/product_info.php/info/p23_Ingwer-im-Honig.html')

[XT SQL Error]