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', '0715dbe6d14e19eabde53d9be9d5e8d9', '18.117.196.184', '1713576618', '1713576618', '/product_info.php/info/p55_Propolistropfen-10-ml-mit-Alkohol.html')

[XT SQL Error]