VARIANCE

Description

The VARIANCE(expr) function returns the population standard variance of expr. Variance is an essential concept in statistics, which is used to measure the degree of dispersion of a set of data values, that is, the difference between the data value and its mean value. If the variance value is large, the difference between the data values ​​is large; conversely, if the variance value is small, the difference between the data values ​​is slight.

Syntax

1. > VARIANCE(expr)

Arguments

Examples

1. CREATE TABLE t1(PlayerName VARCHAR(100) NOT NULL,RunScored INT NOT NULL,WicketsTaken INT NOT NULL);
2. INSERT INTO t1 VALUES('KL Rahul', 52, 0 ),('Hardik Pandya', 30, 1 ),('Ravindra Jadeja', 18, 2 ),('Washington Sundar', 10, 1),('D Chahar', 11, 2 ),  ('Mitchell Starc', 0, 3);

4. -- Calculate the variance of the RunScored column
5. > SELECT VARIANCE(RunScored) as Pop_Standard_Variance FROM t1;
6. +-----------------------+
7. | Pop_Standard_Variance |
8. +-----------------------+
9. |     284.8055555555555 |
10. +-----------------------+
11. 1 row in set (0.01 sec)

13. -- Calculate the variance of the WicketsTaken column
14. mysql> SELECT VARIANCE(WicketsTaken) as Pop_Std_Var_Wickets FROM t1;
15. +---------------------+
16. | Pop_Std_Var_Wickets |
17. +---------------------+
18. |  0.9166666666666665 |
19. +---------------------+
20. 1 row in set (0.01 sec)