i am trying to select first occurrence of the "Quality" column per each Type (A, B, C, ...etc) 

```
infotable
--------
time   Type   quality
1:00   A      1
1:05   A      1
1:10   A      2
1:13   A      2
1:17   A      3
1:20   B      3
1:22   B      2
1:25   B      2
1:30   B      1

and i want the final result to be like this:
--------------------------
time   Type   quality
1:00   A      1
1:10   A      2
1:17   A      3
1:20   B      3
1:22   B      2
1:30   B      1

```

i tried to do it through multiple CTE but failed to get the correct output

```
with 
  cte_type
as (
  select *,
  row_number() over (partition by type order by time asc ) as rn_type
  from infotable
  ),
  cte_quality
  as (
  select *,
  row_number() over (partition by quality order by time asc ) as rn_quality
  from cte_type
  )
select * from cte_quality
where rn_quality = 1;

```

Any thoughts on how i could get the required result would be really appreciated