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', 'h742mgm260v82avu0033n81vo6', '107.22.127.78', '1493220711', '1493220711', '/product_info.php?info=p640_held-Trilogie--Softcover-.html')

[XT SQL Error]