1366 - Incorrect integer value: '' for column `dbbgz2tq`.`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', 'a21e4161d217b9757c3500cacb8206914a1ee179', '34.231.21.83', '1591427607', '1591427607', '/product_info.php?products_id=1404')

[XT SQL Error]