Unary Operators - Negative

Article
05/23/2023

Applies to: SQL Server Azure SQL Database Azure SQL Managed Instance Azure Synapse Analytics Analytics Platform System (PDW) SQL analytics endpoint in Microsoft Fabric Warehouse in Microsoft Fabric

Returns the negative of the value of a numeric expression (a unary operator). Unary operators perform an operation on only one expression of any one of the data types of the numeric data type category.

Operator	Meaning
+ (Positive)	Numeric value is positive.
- (Negative)	Numeric value is negative.
~ (Bitwise NOT)	Returns the ones complement of the number.

The + (Positive) and - (Negative) operators can be used on any expression of any one of the data types of the numeric data type category. The ~ (Bitwise NOT) operator can be used only on expressions of any one of the data types of the integer data type category.

Transact-SQL syntax conventions

Syntax

- numeric_expression

Note

To view Transact-SQL syntax for SQL Server 2014 (12.x) and earlier versions, see Previous versions documentation.

Arguments

numeric_expression
Is any valid expression of any one of the data types of the numeric data type category, except the date and time category.

Result Types

Returns the data type of numeric_expression, except that an unsigned tinyint expression is promoted to a signed smallint result.

Examples

A. Setting a variable to a negative value

The following example sets a variable to a negative value.

USE tempdb;  
GO  
DECLARE @MyNumber DECIMAL(10,2);  
SET @MyNumber = -123.45;  
SELECT @MyNumber AS NegativeValue;  
GO

Here is the result set.

NegativeValue  
---------------------------------------  
-123.45  
  
(1 row(s) affected)

B. Changing a variable to a negative value

The following example changes a variable to a negative value.

USE tempdb;  
GO  
DECLARE @Num1 INT;  
SET @Num1 = 5;  
SELECT @Num1 AS VariableValue, -@Num1 AS NegativeValue;  
GO

Here is the result set.

VariableValue NegativeValue  
------------- -------------  
5             -5  
  
(1 row(s) affected)

Examples: Azure Synapse Analytics and Analytics Platform System (PDW)

C. Returning the negative of a positive constant

The following example returns the negative of a positive constant.

USE ssawPDW;  
  
SELECT TOP (1) - 17 FROM DimEmployee;

Returns

-17

D. Returning the positive of a negative constant

The following example returns the positive of a negative constant.

USE ssawPDW;  
  
SELECT TOP (1) - ( - 17) FROM DimEmployee;