Using Natural Joins.sql
SQL>
SQL>
SQL> CREATE TABLE Room (
2 RoomID INT NOT NULL PRIMARY KEY,
3 Comments VARCHAR(50),
4 Capacity INT);
Table created.
SQL> INSERT INTO Room (RoomID,Comments,Capacity) VALUES (1,'Main hall',500);
1 row created.
SQL> INSERT INTO Room (RoomID,Comments,Capacity) VALUES (2,'Science Department',200);
1 row created.
SQL> INSERT INTO Room (RoomID,Comments,Capacity) VALUES (3,'Science Room 1',100);
1 row created.
SQL> INSERT INTO Room (RoomID,Comments,Capacity) VALUES (4,'Languages Block',300);
1 row created.
SQL> INSERT INTO Room (RoomID,Comments,Capacity) VALUES (5,'Languages Room 1',75);
1 row created.
SQL>
SQL>
SQL>
SQL> CREATE TABLE Class (
2 ClassID INT NOT NULL PRIMARY KEY,
3 CourseID INT NOT NULL,
4 InstructorID INT NOT NULL,
5 RoomID INT NOT NULL,
6 Time VARCHAR(50));
Table created.
SQL> INSERT INTO Class (ClassID,CourseID,InstructorID,RoomID,Time) VALUES (1,1,1,6,'Mon 09:00-11:00');
1 row created.
SQL> INSERT INTO Class (ClassID,CourseID,InstructorID,RoomID,Time) VALUES (2,2,1,5,'Mon 11:00-12:00, Thu 09:00-11:00');
1 row created.
SQL> INSERT INTO Class (ClassID,CourseID,InstructorID,RoomID,Time) VALUES (3,3,2,3,'Mon 14:00-16:00');
1 row created.
SQL> INSERT INTO Class (ClassID,CourseID,InstructorID,RoomID,Time) VALUES (4,4,3,2,'Tue 10:00-12:00, Thu 14:00-15:00');
1 row created.
SQL> INSERT INTO Class (ClassID,CourseID,InstructorID,RoomID,Time) VALUES (5,5,2,9,'Tue 14:00-16:00');
1 row created.
SQL>
SQL> SELECT Class.ClassID,
2 Class.CourseID,
3 Class.Time,
4 Room.Comments AS RoomName
5 FROM Class NATURAL JOIN Room
6 ORDER BY ClassID;
CLASSID COURSEID TIME
---------- ---------- --------------------------------------------------
ROOMNAME
--------------------------------------------------
2 2 Mon 11:00-12:00, Thu 09:00-11:00
Languages Room 1
3 3 Mon 14:00-16:00
Science Room 1
4 4 Tue 10:00-12:00, Thu 14:00-15:00
Science Department
3 rows selected.
SQL>
SQL>
SQL> drop table room;
Table dropped.
SQL> drop table class;
Table dropped.
SQL>
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