1366 - Incorrect integer value: '' for column `dogsdream`.`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', '1c4d7fbe7d65ee2d027574de6ab687fd', '216.73.216.9', '1759386753', '1759386753', '/shop/index.php/cat/c6_Fuer-die--kleinen-.html')

[XT SQL Error]