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', 'b3c5d956f5c4178188ca8d4bb8eb909f', '34.229.24.100', '1563484647', '1563484647', '/product_info.php/info/p771_T-Shirt-Harro.html')

[XT SQL Error]