Unary operators - Positive (Transact-SQL)
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
SQL database in Microsoft Fabric
Returns 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 |
|---|---|
| + (Unary positive) | Numeric value is positive. |
| - (Unary 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
Arguments
numeric_expression
Any valid expression of any one of the data types in the numeric data type category, except the datetime and smalldatetime data types.
Return types
Returns the data type of numeric_expression.
Remarks
Although a unary plus can appear before any numeric expression, it performs no operation on the value returned from the expression. Specifically, it doesn't return the positive value of a negative expression. To return positive value of a negative expression, use the ABS function.
Examples
A. Set a variable to a positive value
The following example sets a variable to a positive value.
USE tempdb;
GO
DECLARE @MyNumber DECIMAL(10, 2);
SET @MyNumber = + 123.45;
SELECT @MyNumber AS PositiveValue;
GO
Here's the result set.
PositiveValue
--------------
123.45
B. Use the unary plus operator with a negative value
The following example shows using the unary plus with a negative expression and the ABS function on the same negative expression. The unary plus doesn't affect the expression, but the ABS() function returns the positive value of the expression.
USE tempdb;
GO
DECLARE @Num1 INT;
SET @Num1 = -5;
SELECT + @Num1 AS NegativeValue,
ABS(@Num1) AS PositiveValue;
GO
Here's the result set.
NegativeValue PositiveValue
-------------- --------------
-5 5