# Unary Operators - Negative

**THIS TOPIC APPLIES TO:**SQL Server (starting with 2008)Azure SQL DatabaseAzure SQL Data Warehouse Parallel Data Warehouse

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

```
-- Syntax for SQL Server, Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse
- numeric_expression
```

## 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 SQL Data Warehouse and Parallel Data Warehouse

### 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;
```

Returns

```
17
```

### E. Returning the negative of a column

The following example returns the negative of the `BaseRate`

value for each employee in the `dimEmployee`

table.

```
USE ssawPDW;
SELECT - BaseRate FROM DimEmployee;
```

## See Also

Data Types (Transact-SQL)

Expressions (Transact-SQL)

Operators (Transact-SQL)