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', 'fskji2ijecs3j37cm8gitdicf4', '216.73.216.217', '1751510463', '1751510463', '/product_info.php?info=p521_Mischung-fuer-Ziertauben-mit-Popcorn-25kg-OzP.html')

[XT SQL Error]