Row_Number Function in sql server

Hi All,

I have a douts about ROW_NUMBER() funcction using sql server, i have a two sample query like below, My problem is my fist query is working fine because its avoiding duplicate datas, compare to my actual table data But my second query is not avoiding duplicate values as well as my SN number always showing 1 but i want to show my SN number should be autoincrement. So how can i achieve this solution, please help me.

My Actual table data is:

id ---- ajson1 ajson1 ajson3 ajson4

query 1:

select DISTINCT id from json order by id asc OUTPUT: id ----- ajson1 ajson3 ajson4

query 2:

SELECT (SELECT DISTINCT ROW_NUMBER() OVER(ORDER BY id ASC)) AS SN, id FROM json

OUTPUT: SN id -- ----- 1 ajson1 1 ajson1 1 ajson3 1 ajson4

thanks in advance