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SQL> create table registrations
2 ( attendee NUMBER(4)
3 , course VARCHAR2(6)
4 , begindate DATE
5 , evaluation NUMBER(1)
6 , constraint R_PK primary key (attendee,course,begindate)
7 ) ;
Table created.
SQL>
SQL> insert into registrations values (2,'SQL',date '2009-04-12',4 );
1 row created.
SQL> insert into registrations values (14,'SQL',date '2009-04-12',5 );
1 row created.
SQL> insert into registrations values (6,'SQL',date '2009-04-12',4 );
1 row created.
SQL> insert into registrations values (11,'SQL',date '2009-04-12',2 );
1 row created.
SQL> insert into registrations values (8,'SQL',date '2009-10-04',NULL);
1 row created.
SQL> insert into registrations values (9,'SQL',date '2009-10-04',3 );
1 row created.
SQL> insert into registrations values (13,'SQL',date '2009-10-04',4 );
1 row created.
SQL> insert into registrations values (13,'SQL',date '2009-12-13',NULL);
1 row created.
SQL> insert into registrations values (6,'SQL',date '2009-12-13',NULL);
1 row created.
SQL> insert into registrations values (3,'OAU',date '2009-08-10',4 );
1 row created.
SQL> insert into registrations values (12,'OAU',date '2009-08-10',4 );
1 row created.
SQL> insert into registrations values (13,'OAU',date '2009-08-10',5 );
1 row created.
SQL>
SQL> select attendee, begindate
2 , case evaluation
3 when 1 then 'bad'
4 when 2 then 'mediocre'
5 when 3 then 'ok'
6 when 4 then 'good'
7 when 5 then 'excellent'
8 else 'not filled in'
9 end
10 from registrations
11 where course = 'SQL';
ATTENDEE BEGINDATE CASEEVALUATIO
---------- ---------- -------------
2 12-04-2009 good
14 12-04-2009 excellent
6 12-04-2009 good
11 12-04-2009 mediocre
8 04-10-2009 not filled in
9 04-10-2009 ok
13 04-10-2009 good
13 13-12-2009 not filled in
6 13-12-2009 not filled in
9 rows selected.
SQL>
SQL>
SQL> drop table registrations;
Table dropped.
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