STDDEV Function

Returns the statistical standard deviation of all values in an expression.

Categories: Aggregate
Descriptive Statistics
Alias: STD
Returned data type: DOUBLE

Syntax

STDDEV(expression)

Arguments

expression

specifies any valid SQL expression.

Interaction At least two valid values are required in the column to perform the calculation. Otherwise the function returns a null value.
Data type DOUBLE
See <sql-expression>
FedSQL Expressions

Details

The standard deviation is calculated as the square root of the variance.
Null values and SAS missing values are ignored and are not included in the computation.
You can use an aggregate function to produce a statistical summary of data in the entire table that is listed in the FROM clause or for each group that is specified in a GROUP BY clause. The GROUP BY clause groups data by a specified column or columns. When you use a GROUP BY clause, the aggregate function in the SELECT clause or in a HAVING clause instructs FedSQL in how to summarize the data for each group. FedSQL calculates the aggregate function separately for each group. If GROUP BY is omitted, then all the rows in the table or view are considered to be a single group.

Example

The following statement illustrates the STDDEV function:
Statements
Results
select stddev(AvgHigh) from worldtemps;
7.811414

See Also

SELECT Statement Clauses:
Last updated: February 23, 2017