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STDDEV,STDDEV_POP

STDDEV,STDDEV_POP

description

Syntax

STDDEV(expr)

返回expr表达式的标准差

example

MySQL > select stddev(scan_rows) from log_statis group by datetime;
+---------------------+
| stddev(`scan_rows`) |
+---------------------+
| 2.3736656687790934 |
+---------------------+

MySQL > select stddev_pop(scan_rows) from log_statis group by datetime;
+-------------------------+
| stddev_pop(`scan_rows`) |
+-------------------------+
| 2.3722760595994914 |
+-------------------------+

keywords

STDDEV,STDDEV_POP,POP