VAR_POP

函数说明

VAR_POP() 是一个聚合函数，计算总体方差。与 VARIANCE() 为同义词。

函数语法

1. > VAR_POP(expr)

参数释义

参数 说明
expr 任何数值类型的列的列名

示例

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. -- 计算 RunScored 列的方差
5. mysql> SELECT VAR_POP(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. -- 计算 WicketsTaken 列的方差
14. mysql> SELECT VAR_POP(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)