subtract-transact-sql.md

title	- (Subtraction) (Transact-SQL)
description	- (Subtraction) (Transact-SQL)
author	rwestMSFT
ms.author	randolphwest
ms.reviewer
ms.date	03/15/2017
ms.prod	sql
ms.prod_service	database-engine, sql-database, synapse-analytics, pdw
ms.technology	t-sql
ms.topic	reference
ms.custom
f1_keywords	subtract - -_TSQL
helpviewer_keywords	- (subtract) subtract operator (-) minus operator (-) subtracting numbers
dev_langs	TSQL
monikerRange	>= aps-pdw-2016 || = azuresqldb-current || = azure-sqldw-latest || >= sql-server-2016 || >= sql-server-linux-2017 || = azuresqldb-mi-current

- (Subtraction) (Transact-SQL)

[!INCLUDE sql-asdb-asdbmi-asa-pdw]

Subtracts two numbers (an arithmetic subtraction operator). Can also subtract a number, in days, from a date.

Transact-SQL Syntax Conventions

Syntax

expression - expression  

[!INCLUDEsql-server-tsql-previous-offline-documentation]

Arguments

expression
Is any valid expression of any one of the data types of the numeric data type category, except the bit data type. Cannot be used with date, time, datetime2, or datetimeoffset data types.

Result Types

Returns the data type of the argument with the higher precedence. For more information, see Data Type Precedence (Transact-SQL).

Examples

A. Using subtraction in a SELECT statement

The following example calculates the difference in tax rate between the state or province with the highest tax rate and the state or province with the lowest tax rate.

Applies to: [!INCLUDEssNoVersion] and [!INCLUDEssSDS].

-- Uses AdventureWorks  
  
SELECT MAX(TaxRate) - MIN(TaxRate) AS 'Tax Rate Difference'  
FROM Sales.SalesTaxRate  
WHERE StateProvinceID IS NOT NULL;  
GO  

You can change the order of execution by using parentheses. Calculations inside parentheses are evaluated first. If parentheses are nested, the most deeply nested calculation has precedence.

B. Using date subtraction

The following example subtracts a number of days from a datetime date.

Applies to: [!INCLUDEssNoVersion] and [!INCLUDEssSDS].

-- Uses the AdventureWorks sample database
DECLARE @altstartdate DATETIME;  
SET @altstartdate = CONVERT(DATETIME, 'January 10, 1900 3:00 AM', 101);  
SELECT @altstartdate - 1.5 AS 'Subtract Date';  

Here is the result set:

Subtract Date  
-----------------------  
1900-01-08 15:00:00.000  

(1 row(s) affected)

Examples: [!INCLUDEssSDWfull] and [!INCLUDEssPDW]

C: Using subtraction in a SELECT statement

The following example calculates the difference in a base rate between the employee with the highest base rate and the employee with the lowest tax rate, from the dimEmployee table.

-- Uses AdventureWorks  
  
SELECT MAX(BaseRate) - MIN(BaseRate) AS BaseRateDifference  
FROM DimEmployee;  

See Also

-= (Subtraction Assignment) (Transact-SQL)
Compound Operators (Transact-SQL)
Arithmetic Operators (Transact-SQL)
- (Negative) (Transact-SQL)
Data Types (Transact-SQL)
Expressions (Transact-SQL)
Built-in Functions (Transact-SQL)
SELECT (Transact-SQL)