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', '80g4gqmv7jrkocmq89bsknbqv0', '3.21.158.197', '1739000922', '1739000922', '/index.php?XTCsid=u26kusssenv9nf8n7cr2rtvfn3&cat=c197_AEG-Werkzeug-Akku.html')

[XT SQL Error]