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', '3752d5d76c6cf8c53e669a8704205675', '44.200.249.42', '1711659032', '1711659032', '/index.php')

[XT SQL Error]