Stddevw_pop Function
The stddevw_pop function returns the weighted standard deviation of the population for a set of values.
The syntax of the stddevw_pop function is
stddevw_pop(x[,w])
x are the values for which the standard deviation of the population
shall be calculated.
Null values are ignored.
If the number of
values is zero, the function returns null.
w are the weights.
If no value is provided the weight is assumed to be 1.
Example
SELECT country, stddevw_pop(price) FROM sales GROUP BY country;