get value comma separated sql server

DECLARE @UserMaster TABLE( 

    UserID INT NOT NULL, 

    UserName varchar(30) NOT NULL 

); 

INSERT INTO @UserMaster VALUES (1,'Rakesh')

INSERT INTO @UserMaster VALUES (2,'Ashish')

INSERT INTO @UserMaster VALUES (3,'Sagar')

SELECT * FROM @UserMaster

DECLARE @CSV VARCHAR(MAX) 

SELECT @CSV = COALESCE(@CSV + ', ', '') + UserName from @UserMaster 

SELECT @CSV AS Result