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', 'u6clvmdssqfqec396mkf6gu4i6', '216.73.216.220', '1764902704', '1764902704', '/product_info.php?info=p610_Stehtisch-warm--Feuertonne--ohne-Ofenrohrhaube-.html')

[XT SQL Error]