CREATE TABLE HOST (Name VARCHAR2, Host_ID VARCHAR2)
CREATE TABLE party_host (Name VARCHAR2, Host_ID VARCHAR2)

List the names of hosts who did not serve as a host of any party in our record.
SELECT Name FROM HOST WHERE NOT Host_ID IN (SELECT Host_ID FROM party_host)
SELECT "Name" FROM "HOST" WHERE NOT "Host_ID" IN (SELECT "Host_ID" FROM "party_host")