Getting Column Averages
/* mysql> SELECT AVG(Mark) AS AverageMark -> FROM StudentExam -> WHERE StudentID = 10; +-------------+ | AverageMark | +-------------+ | 73.3333 | +-------------+ 1 row in set (0.00 sec) */ /* Create table */ Drop TABLE StudentExam; CREATE TABLE StudentExam ( StudentID INT NOT NULL, Mark INT, Comments VARCHAR(255) )TYPE = InnoDB; /* Insert data */ INSERT INTO StudentExam (StudentID,Mark,Comments) VALUES (10,76,'Java'); INSERT INTO StudentExam (StudentID,Mark,Comments) VALUES (10,65,'C#'); INSERT INTO StudentExam (StudentID,Mark,Comments) VALUES (10,79,'JavaScript'); /* Real command */ SELECT AVG(Mark) AS AverageMark FROM StudentExam WHERE StudentID = 10;
1. | Use AVG and alias | ||
2. | Use AVG and SUM together | ||
3. | Use AVG and compare |