How do I use the CONCAT function in SQL Server 2008 R2?

Solution 1:

Just for completeness - in SQL 2008 you would use the plus + operator to perform string concatenation.

Take a look at the MSDN reference with sample code. Starting with SQL 2012, you may wish to use the new CONCAT function.

Solution 2:

CONCAT is new to SQL Server 2012. The link you gave makes this clear, it is not a function on Previous Versions, including 2008 R2.

That it is part of SQL Server 2012 can be seen in the document tree:

SQL Server 2012  
Product Documentation  
Books Online for SQL Server 2012  
Database Engine  
  Transact-SQL Reference (Database Engine)  
    Built-in Functions (Transact-SQL)  
      String Functions (Transact-SQL)

EDIT Martin Smith helpfully points out that SQL Server provides an implementation of ODBC's CONCAT function.

Solution 3:

I suggest you cast all columns before you concat them

cast('data1' as varchar) + cast('data2' as varchar) + cast('data3' as varchar)

This should work for you.

Solution 4:

CONCAT, as stated, is not supported prior to SQL Server 2012. However you can concatenate simply using the + operator as suggested. But beware, this operator will throw an error if the first operand is a number since it thinks will be adding and not concatenating. To resolve this issue just add '' in front. For example

someNumber + 'someString' + .... + lastVariableToConcatenate

will raise an error BUT '' + someNumber + 'someString' + ...... will work just fine.

Also, if there are two numbers to be concatenated make sure you add a '' between them, like so

.... + someNumber + '' + someOtherNumber + .....

Solution 5:

NULL safe drop in replacement approximations for SQL Server 2012 CONCAT function

SQL Server 2012:

SELECT CONCAT(data1, data2)

PRE SQL 2012 (Two Solutions):

SELECT {fn CONCAT(ISNULL(data1, ''), ISNULL(data2, ''))}

SELECT ISNULL(CAST(data1 AS varchar(MAX)), '') + ISNULL(CAST(data2 AS varchar(MAX)), '')

These two solutions collate several excellent answers and caveats raised by other posters including @Martin Smith, @Svish and @vasin1987.

These options add NULL to '' (empty string) casting for safe NULL handling while accounting for the varying behaviour of the + operator pertaining to specific operands.

Note the ODBC Scaler Function solution is limited to 2 arguments whereas the + operator approach is scalable to many arguments as needed.

Note also the potential issue identified by @Swifty regarding the default varchar size here remedied by varchar(MAX).