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', '4sevlmj6nosg4uchl8mo05hj20', '2600:1f28:365:80b0:9d91:fa12:fda7:2c13', '1788793303', '1788793303', '/')

[XT SQL Error]