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', '572i4tslm2crjh3ur18sh2ecs1', '216.73.216.211', '1762308790', '1762308790', '/product_info.php?info=p610_Stehtisch-warm--Feuertonne--ohne-Ofenrohrhaube-.html')

[XT SQL Error]