Compound Operators (Transact-SQL)
Applies to: 
SQL Server
Azure SQL Database
Azure SQL Managed Instance
Compound operators execute some operation and set an original value to the result of the operation. For example, if a variable @x equals 35, then @x += 2 takes the original value of @x, add 2 and sets @x to that new value (37).
Transact-SQL provides the following compound operators:
| Operator | Link to more information | Action |
|---|---|---|
| += | += (Add Assignment) (Transact-SQL) | Adds some amount to the original value and sets the original value to the result. |
| -= | -= (Subtract Assignment) (Transact-SQL) | Subtracts some amount from the original value and sets the original value to the result. |
| *= | *= (Multiply Assignment) (Transact-SQL) | Multiplies by an amount and sets the original value to the result. |
| /= | (Divide Assignment) (Transact-SQL) | Divides by an amount and sets the original value to the result. |
| %= | Modulus Assignment (Transact-SQL) | Divides by an amount and sets the original value to the modulo. |
| &= | &= (Bitwise AND Assignment) (Transact-SQL) | Performs a bitwise AND and sets the original value to the result. |
| ^= | ^= (Bitwise Exclusive OR Assignment) (Transact-SQL) | Performs a bitwise exclusive OR and sets the original value to the result. |
| |= | |= (Bitwise OR Assignment) (Transact-SQL) | Performs a bitwise OR and sets the original value to the result. |
Syntax
expression operator expression
Arguments
expression
Is any valid expression of any one of the data types in the numeric category.
Result Types
Returns the data type of the argument with the higher precedence. For more information, see Data Type Precedence (Transact-SQL).
Remarks
For more information, see the topics related to each operator.
Examples
The following examples demonstrate compound operations.
DECLARE @x1 INT = 27;
SET @x1 += 2 ;
SELECT @x1 AS Added_2;
DECLARE @x2 INT = 27;
SET @x2 -= 2 ;
SELECT @x2 AS Subtracted_2;
DECLARE @x3 INT = 27;
SET @x3 *= 2 ;
SELECT @x3 AS Multiplied_by_2;
DECLARE @x4 INT = 27;
SET @x4 /= 2 ;
SELECT @x4 AS Divided_by_2;
DECLARE @x5 INT = 27;
SET @x5 %= 2 ;
SELECT @x5 AS Modulo_of_27_divided_by_2;
DECLARE @x6 INT = 9;
SET @x6 &= 13 ;
SELECT @x6 AS Bitwise_AND;
DECLARE @x7 INT = 27;
SET @x7 ^= 2 ;
SELECT @x7 AS Bitwise_Exclusive_OR;
DECLARE @x8 INT = 27;
SET @x8 |= 2 ;
SELECT @x8 AS Bitwise_OR;