STDDEV_POP
Aggregate function.
The STDDEV_POP() function returns the population standard deviation(the square root of VAR_POP()) of an expression.
提示
STD() or STDDEV() can also be used, which are equivalent but not standard SQL.
警告
NULL values are not counted.
Syntax
STDDEV_POP(expression)
STDDEV(expression)
STD(expression)
Arguments
Arguments | Description |
---|---|
expression | Any numerical expression |
Return Type
double
Examples
提示
numbers(N) – A table for test with the single number
column (UInt64) that contains integers from 0 to N-1.
SELECT STDDEV_POP(number) FROM numbers(10000);
+--------------------+
| STDDEV_POP(number) |
+--------------------+
| 2886.751331514372 |
+--------------------+
SELECT STDDEV(number) FROM numbers(1000);
+--------------------+
| STDDEV(number) |
+--------------------+
| 288.67499025720946 |
+--------------------+
SELECT STD(number) FROM numbers(100);
+-------------------+
| STD(number) |
+-------------------+
| 28.86607004772212 |
+-------------------+