Get distinct name from table

SELECT DISTINCT Name FROM TableName

IF((SELECT COUNT(*) FROM Users WHERE username = @username) > 0)
BEGIN
   -- USER ALREADY EXISTS
END
ELSE
BEGIN
   INSERT INTO Users(username, password)
   VALUES (username, password)
END

SELECT DISTINCT name
FROM TableName

with CTE(Name,Action_ID,dupname) as
            (select Name,Action_ID,ROW_NUMBER() over(partition by Name order by Name) as dupname  from ActionTypeMaster )
            select * from CTE where dupname=1   order by Name