STDDEV,STDDEV_POP

description

Syntax

STDDEV(expr)

返回expr表达式的标准差

example

1. MySQL > select stddev(scan_rows) from log_statis group by datetime;
2. +---------------------+
3. | stddev(`scan_rows`) |
4. +---------------------+
5. |  2.3736656687790934 |
6. +---------------------+

8. MySQL > select stddev_pop(scan_rows) from log_statis group by datetime;
9. +-------------------------+
10. | stddev_pop(`scan_rows`) |
11. +-------------------------+
12. |      2.3722760595994914 |
13. +-------------------------+

keywords

STDDEV,STDDEV_POP,POP