SQL Server QUOTENAME() Function

Return a Unicode string with bracket delimiters (default):

SELECT QUOTENAME('abcdef');

Definition and Usage

The QUOTENAME() function returns a Unicode string with delimiters added to make the string a valid SQL Server delimited identifier.

QUOTENAME(string, quote_char)

Parameter	Description
string	Required. A string of Unicode character data. Limited to 128 characters
quote_char	Optional. A one-character string to use as the delimiter. Can be a single quotation mark ( ' ), a left or right bracket ( [] ), a double quotation mark ( " ), a left or right parenthesis ( () ), a greater than or less than sign ( >< ), a left or right brace ( {} ) or a backtick ( ` ). If quote_char is not specified, brackets are used.

Works in:	SQL Server (starting with 2008), Azure SQL Database, Azure SQL Data Warehouse, Parallel Data Warehouse

Return a Unicode string with parenthesis delimiters:

SELECT QUOTENAME('abcdef', '()');