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', 'namtpei9tmkolrjqkh5da1bvg7', '52.15.201.192', '1738998999', '1738998999', '/index.php?XTCsid=b08vstu7leg8ef8i43caoskln6&cat=c672_Tablet-PC---E-Book-Akku.html')

[XT SQL Error]