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', '1fdc7ec5c3c9aa2c2792bee9452a75cc', '34.229.24.100', '1563486457', '1563486457', '/product_info.php/info/p689_Hip-Slip-365.html')

[XT SQL Error]