VAR (Transact-SQL)
Returns the statistical variance of all values in the specified expression. May be followed by the OVER clause.
Transact-SQL Syntax Conventions
Syntax
VAR ( [ ALL | DISTINCT ] expression )
Arguments
ALL
Applies the function to all values. ALL is the default.DISTINCT
Specifies that each unique value is considered.expression
Is an expression of the exact numeric or approximate numeric data type category, except for the bit data type. Aggregate functions and subqueries are not permitted.
Return Types
float
Remarks
If VAR is used on all items in a SELECT statement, each value in the result set is included in the calculation. VAR can be used with numeric columns only. Null values are ignored.
Examples
The following example returns the variance for all bonus values in the SalesPerson table.
USE AdventureWorks2012;
GO
SELECT VAR(Bonus)
FROM Sales.SalesPerson;
GO