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', '3e7fa12428dae836f8a64e4f59d36e4b', '34.229.24.100', '1563485223', '1563485223', '/shop_content.php/coID/2/content/Privacy-Notice')

[XT SQL Error]