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', 'pbme8l8q5ntkpdsrn3e6l861h3', '3.141.7.31', '1747147123', '1747147123', '/product_info.php?info=p634_802004-Deckel-fuer-160-Liter-Elektro-Futterdaempfer.html')

[XT SQL Error]