VARIANCE¶
Function Description¶
VARIANCE(expr) is an aggregate function that calculates the population variance. Variance is an important concept in statistics, used to measure the degree of dispersion of a set of data values, i.e. the difference between the data values and their averages. If the variance value is large, it means that the difference between the data values is large; conversely, if the variance value is small, it means that the difference between the data values is small.
Function Syntax¶
> VARIANCE(expr)
Parameter definition¶
Parameters |
Description |
|---|---|
expr |
Column name of any numeric type |
Example¶
CREATE TABLE t1(PlayerName VARCHAR(100) NOT NULL,RunScored INT NOT NULL,WicketsTaken INT NOT NULL);
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);
-- Calculate the variance of the RunScored column
> SELECT VARIANCE(RunScored) as Pop_Standard_Variance FROM t1;
+---------------------------+
| Pop_Standard_Variance |
+---------------------------+
| 284.8055555555555555 |
+---------------------------+
1 row in set (0.01 sec)
-- Calculate the variance of the WicketsTaken column
mysql> SELECT VARIANCE(WicketsTaken) as Pop_Std_Var_Wickets FROM t1;
+--------------------------+
| Pop_Std_Var_Wickets |
+--------------------------+
| 0.9166666666666666666665 |
+--------------------------+
1 row in set (0.01 sec)