I was looking for a CONCAT function in SQL Server 2008 R2. I found the link for this function. But when I use this function, it gives the following error:
Msg 195, Level 15, State 10, Line 7
'CONCAT' is not a recognized built-in function name.
Does the CONCAT function exists in SQL Server 2008 R2?
If not, how do I concatenate strings in SQL Server 2008 R2?
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.