1366 - Incorrect integer value: '' for column `usr_web74_1`.`whos_online`.`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', '1trgl1utpm8knrq12g8t3hpll4', '216.73.216.40', '1766139595', '1766139595', '/index.php?cat=c3_Holzschnitzereien.html')

[XT SQL Error]