1366 - Incorrect integer value: '' for column `mapshopatlogis`.`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', 'c4a8bd7de07b16df09879f7e13f81aa2', '216.73.216.116', '1752277738', '1752277738', '/index.php/cat/c44_3D-Karten.html?refID=1')

[XT SQL Error]