StDev

2005
2008
2012
2014
2016
2017
2019
2022

2005, 2008, 2012, 2014, 2016, 2017, 2019, 2022

StDev (Standard Deviation) Aggregate Function

Use the StDev function to return the statistical standard deviation for all values in the specified expression.

Syntax

db.fx.StDev({expression})[.Distinct()]

Arguments

expression: – The field expression, composite element, or function result to use in calculating the standard deviation.

Distinct(): – Each unique value is considered while calculating the standard deviation for the population.

Returns

float

Examples

Select Statement

Select the standard deviation of product shipping weights.

float result = db.SelectOne(
        db.fx.StDev(dbo.Product.ShippingWeight)
    )
    .From(dbo.Product)
    .Execute();

Order By Clause

Select the standard deviation of product shipping weights ordered by the standard deviation of product shipping weights descending.

float result = db.SelectOne(
        db.fx.StDev(dbo.Product.ShippingWeight)
    )
    .From(dbo.Product)
    .OrderBy(db.fx.StDev(dbo.Product.ShippingWeight).Desc())
    .Execute();

Having Clause

Select the product categories of all products, grouped by product category type having standard deviation greater than 1.

IEnumerable<ProductCategoryType?> results = db.SelectMany(
        dbo.Product.ProductCategoryType
    )
    .From(dbo.Product)
    .GroupBy(dbo.Product.ProductCategoryType)
    .Having(db.fx.StDev(dbo.Product.ShippingWeight) > 1)
    .Execute();