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', 'pr2siud2qldjqjr8blc487fg66', '216.73.216.130', '1761208606', '1761208606', '/index.php?XTCsid=d3f81aac1b90a5822d8663a3af39931e&cat=c5_Crockery.html')

[XT SQL Error]