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', '4ede17180f9d7de8fa77eac2ae2e1246', '34.229.24.100', '1563485055', '1563485055', '/shop_content.php/coID/9/product/SSL-Security')

[XT SQL Error]