Using Analytic Functions: AVG(Mark) OVER (ORDER BY StudentID, Mark)
SQL>
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>
SQL> SELECT StudentID, Mark, AVG(Mark) OVER
2 (ORDER BY StudentID, Mark) Running_Average
3 FROM SAT
4 ORDER BY StudentID, Mark;
STUDENTID MARK RUNNING_AVERAGE
---------- ---------- ---------------
1 55 55
1 73 64
2 39 55.6666667
2 44 52.75
2 63 54.8
5 rows selected.
SQL>
SQL>
SQL>
SQL>
SQL> drop table SAT;
Table dropped.
Related examples in the same category