SQL 用于在给定条件下选择第二行

Question

A table in snowflake. We have few ref_id's. Each ref_id is associated with n no.of ord_id with corresponding status.

ref_id	ord_id	status
R1	03	Close
R1	01	Active
R1	02	Active
R2	07	null
R2	04	Close
R2	05	Active
R3	08	Close
R3	09	null

I want to have a new column latest_status which will have the status of highest ord_id for each ref_id. One more condition is that if the status is null for highest ord_id and if its second highest ord_id status is Active then latest should have active status.

Expected result:

ref_id	ord_id	status	latest_status
R1	03	Close	Close
R1	02	Active	Close
R1	01	Active	Close
R2	07	null	Active
R2	05	Active	Active
R2	04	Close	Active
R3	09	null	null
R3	08	Close	null

Can someone please help me with the sql for this? I have tried below sql but it is failing for the R2 red_id result.

select distinct ord_id,status, IFF(status is NULL,NTH_VALUE(IFF(status IN ('Active','Renew'),status,null),2)OVER(PARTITION BY ref_id ORDER BY ord_id desc), FIRST_VALUE(status) OVER(PARTITION BY ref_id ORDER BY ord_id DESC))as latest_status from table where ref_id='R2'

Answer 1

Not fully tested and @isolated's question will be something to bear in mind, something like so. I've used a table var @t which will be your source. You dont say what DBMS you are using either, so there will be some short-cuts possible i imagine.

select * ,
(select sts from @t as t3 where t3.ref=t1.ref and t3.ord=
(select max(ord) from @t as t2 where t2.ref=t1.ref) ) as LATEST
from 
@t as t1

Answer 2

I could get it by doing below

select distinct ord_id,status, FIRST_VALUE(IFF(status is NULL, IFF(B.next IN('Active','Renew'),next,null),status))OVER(PARTITION BY A.ref_id ORDER BY ord_id DESC)as latest from table A LEFT JOIN (select distinct ref_id,FIRST_VALUE(status)OVER(PARTITION BY ref_id ORDER BY ord_id desc) as next from table where status is not null)B on A.ref_id = B.ref_id;