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', 'imvm4tb5pg1r3tlsj7cng1ae77', '216.73.216.165', '1752308482', '1752308482', '/index.php?cat=c2_Decoration.html&XTCsid=33509f1bee4ee2cbb673a74e5faae0d4')

[XT SQL Error]