numeric_expression

Any valid expression in SQL Server Compact 4.0 of any one of the data types in the numeric data type category, except the datetime data type.

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

The following examples use the Orders table to show how the positive and negative unary operators function. When a positive unary operator is set against a negative value, the returned value is negative (positive_value * negative_value = negative_value). When a negative unary operator is set against a negative value, the returned value is positive (negative_value * negative_value = positive_value).

SELECT (DATEPART(day, Order Date) - DATEPART(day, Shipped Date)) 
FROM Orders 
WHERE OrderID = '10248'
-- Without a unary operator, the value returned is '-12'.

SELECT +(DATEPART(day, Order Date) - DATEPART(day, Shipped Date)) 
FROM Orders 
WHERE OrderID = '10248'
-- With the positive unary operator, the value returned is '-12'.

SELECT -(DATEPART(day, Order Date) - DATEPART(day, Shipped Date)) 
FROM Orders 
WHERE OrderID = '10248'
-- With the negative unary operator, the value returned is '12'.