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SQL>
SQL> CREATE TABLE SAT (
2 StudentID INT NOT NULL,
3 ExamID INT NOT NULL,
4 Mark INT,
5 IfPassed SMALLINT,
6 Comments VARCHAR(255),
7 CONSTRAINT PK_SAT PRIMARY KEY (StudentID, ExamID));
Table created.
SQL>
SQL>
SQL> INSERT INTO SAT (StudentID,ExamID,Mark,IfPassed,Comments) VALUES (1,1,55,1,'Satisfactory');
1 row created.
SQL> INSERT INTO SAT (StudentID,ExamID,Mark,IfPassed,Comments) VALUES (1,2,73,1,'Good result');
1 row created.
SQL> INSERT INTO SAT (StudentID,ExamID,Mark,IfPassed,Comments) VALUES (2,3,44,1,'Hard');
1 row created.
SQL> INSERT INTO SAT (StudentID,ExamID,Mark,IfPassed,Comments) VALUES (2,5,39,0,'Simple');
1 row created.
SQL> INSERT INTO SAT (StudentID,ExamID,Mark,IfPassed) VALUES (2,6,63,1);
1 row created.
SQL>
SQL>
SQL> SELECT StudentID, AverageMark FROM (
2 SELECT StudentID, AVG(Mark) AS AverageMark
3 FROM SAT
4 GROUP BY StudentID
5 ORDER BY AverageMark DESC
6 )
7 WHERE ROWNUM <= 5;
STUDENTID AVERAGEMARK
---------- -----------
1 64
2 48.6666667
2 rows selected.
SQL>
SQL> drop table SAT;
Table dropped.
SQL>
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