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', '80c5cfe1e8bee4e0b352025763dff984', '34.229.24.100', '1563484544', '1563484544', '/index.php/cat/c17_sloggi.html')

[XT SQL Error]