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', 'fcbi09ursdnoudgjsv4dm364q7', '216.73.216.113', '1775328722', '1775328722', '/product_info.php?XTCsid=ee199fdb171da456469b100b0e4b3f11&info=p18_Fun-Hat.html')

[XT SQL Error]