+= (String Concatenation) (Transact-SQL)
Concatenates two strings and sets the string to the result of the operation. For example, if a variable @x equals 'Adventure', then @x += 'Works' takes the original value of @x, adds 'Works' to the string, and sets @x to that new value 'AdventureWorks'.
Syntax
expression += expression
Result Types
Returns the data type that is defined for the variable.
Remarks
SET @v1 += 'expression' is equivalent to SET @v1 = @v1 + 'expression'.
The += operator cannot be used without a variable. For example, the following code will cause an error:
SELECT 'Adventure' += 'Works'
Examples
The following example concatenates using the += operator.
DECLARE @v1 varchar(40);
SET @v1 = 'This is the original.';
SET @v1 += ' More text.';
PRINT @v1;
Here is the result set.
This is the original. More text.