SQL>
SQL> create table registrations
2 ( attendee NUMBER(4)
3 , course VARCHAR2(6)
4 , begindate DATE
5 , evaluation NUMBER(1)) ;
Table created.
SQL>
SQL> insert into registrations values (1, 'SQL',date '1999-04-12',4 );
1 row created.
SQL> insert into registrations values (2, 'SQL',date '1999-12-13',NULL);
1 row created.
SQL> insert into registrations values (3, 'SQL',date '1999-12-13',NULL);
1 row created.
SQL> insert into registrations values (4, 'OAU',date '1999-08-10',4 );
1 row created.
SQL> insert into registrations values (5, 'OAU',date '2000-09-27',5 );
1 row created.
SQL> insert into registrations values (6, 'JAV',date '1999-12-13',2 );
1 row created.
SQL> insert into registrations values (7, 'JAV',date '2000-02-01',4 );
1 row created.
SQL> insert into registrations values (8, 'JAV',date '2001-02-01',5 );
1 row created.
SQL> insert into registrations values (9, 'XML',date '2002-02-03',4 );
1 row created.
SQL> insert into registrations values (10,'XML',date '2003-02-03',5 );
1 row created.
SQL> insert into registrations values (1, 'PLS',date '2004-09-11',NULL);
1 row created.
SQL> insert into registrations values (2, 'PLS',date '2005-09-11',NULL);
1 row created.
SQL> insert into registrations values (3, 'PLS',date '2006-09-11',NULL);
1 row created.
SQL>
SQL> select *
2 from registrations
3 where evaluation not in (1,2,3,NULL);
no rows selected
SQL>
SQL> drop table registrations;
Table dropped.
SQL>