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SQL>
SQL>
SQL> create table registrations
2 ( attendee NUMBER(4)
3 , course VARCHAR2(6)
4 , begindate DATE
5 , evaluation NUMBER(1)) ;
Table created.
SQL>
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 '2000-02-01',5 );
1 row created.
SQL> insert into registrations values (9, 'XML',date '2000-02-03',4 );
1 row created.
SQL> insert into registrations values (10,'XML',date '2000-02-03',5 );
1 row created.
SQL> insert into registrations values (1, 'PLS',date '2000-09-11',NULL);
1 row created.
SQL> insert into registrations values (2, 'PLS',date '2000-09-11',NULL);
1 row created.
SQL> insert into registrations values (3, 'PLS',date '2000-09-11',NULL);
1 row created.
SQL>
SQL>
SQL>
SQL> select r.course, r.begindate
2 , count(r.attendee) as attendees
3 from registrations r
4 group by r.course, r.begindate;
COURSE BEGINDATE ATTENDEES
------ --------- ----------
OAU 27-SEP-00 1
PLS 11-SEP-00 3
SQL 12-APR-99 1
JAV 13-DEC-99 1
SQL 13-DEC-99 2
JAV 01-FEB-00 2
XML 03-FEB-00 2
OAU 10-AUG-99 1
8 rows selected.
SQL>
SQL>
SQL> drop table registrations;
Table dropped.
SQL>
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