1366 - Incorrect integer value: '' for column `CP_as15`.`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', 'mmhj3g4mb6mpj8il6j4skk3nv7', '3.142.248.196', '1739000948', '1739000948', '/index.php?XTCsid=u26kusssenv9nf8n7cr2rtvfn3&cat=c1084_Fromm-Werkzeug-Akku.html')

[XT SQL Error]