1366 - Incorrect integer value: '' for column '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', '5o45152b886pp8d5f27qd7d0r5', '216.73.216.185', '1752524596', '1752524596', '/index.php?XTCsid=00627ba1853bf525c018460fff50521f')

[XT SQL Error]