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', '28ded890db6ab6990b1916da06da885c', '3.15.236.219', '1738734622', '1738734622', '/index.php/cat/c19_Reliefkarten-Digital.html?refID=1')

[XT SQL Error]