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', '8t4fq1eb7u07o630127l2b0a96', '216.73.216.47', '1758118496', '1758118496', '/product_info.php?info=p493_Futterdaempfer-Gr--160--Liter-vollverzinkt.html')

[XT SQL Error]