Description
Calculates the standard deviation of an aggregation of values.
Syntax
StdDev ( n )
Arguments
n is a numeric expression.
Example
Returns the average and standard deviation of each continent's female population.
select Continent, Avg(Pop_Fem) as Average, StdDev(Pop_Fem) as StandardDeviation from countries group by Continent
Remarks
StdDev is an aggregation function which can only be used in an aggregating Select statement. Null values are ignored. If there are only null values supplied in the aggregation, then a null value is returned.