Suggest SQL query for given use case - sql

Question

Original Table
Id | Time | Status
------------------
1 | 5 | T
1 | 6 | F
2 | 3 | F
1 | 2 | F
2 | 4 | T
3 | 7 | F
2 | 3 | T
3 | 1 | F
4 | 7 | H
4 | 6 | S
4 | 5 | F
4 | 4 | T
5 | 5 | S
5 | 6 | F
Expected Table
Id | Time | Status
------------------
1 | 6 | F
3 | 7 | F
4 | 5 | F
I want all the distinct ids who have status as F but time should be maximum, if for any id status is T for given maximum time then that id should not be picked. Also only those ids should be picked who have at-least one T. For e.g 4 will not be picked at it doesn't have any 'T' as status.
Please help in writing the SQL query.

Answer 1

You can use EXISTS and NOT EXISTS in the WHERE clause:
select t.*
from tablename t
where t.status = 'F'
and exists (select 1 from tablename where id = t.id and status = 'T')
and not exists (
select 1
from tablename
where id = t.id and status in ('F', 'T') and time > t.time
)
See the demo.
Results:
| Id | Time | Status |
| --- | ---- | ------ |
| 1 | 6 | F |
| 4 | 5 | F |

Answer 2

Try the below way -
select * from tablename t
where time = (select max(time) from tablename t1 where t.id=t1.id and Status='F')
and Status='F'

Answer 3

the following should work
select id,max(time) as time,status
from table
where status='F'
group by id,status

Answer 4

select id, max(time), status
from stuff s
where status = 'F'
and id not in (
select id
from stuff s2
where s2.id = s.id
and s2.time > s.time
and s2.status = 'T')
group by id, status;
You can see the Fiddle here.
As I understand it, you want to find the highest time for each ID (max(time)) where the status is F, but only if there isn't a later record where the status is 'T'. The sub query filters out records where there exists a later record where the status is T.

Answer 5

WITH MAX_TIME_ID AS (
SELECT
ID
,MAX(TIME) AS MAX_TIME
GROUP BY
ID
)
SELECT
O.*
FROM
ORIGINAL_TABLE O
INNER JOIN
MAX_TIME_ID MAX
ON
O.ID = MAX.ID
WHERE
O.STATUS = 'F'
The CTE will find the max time for each ID and the inner join with the where clause on the status will select it only if the latest is 'F'.

Answer 6

I would just use window functions:
select t.*
from (select t.*
row_number() over (partition by id order by time desc) as seqnum,
sum(case when status = 'T' then 1 else 0 end) over (partition by id) as num_t
from t
) t
where num_t > 0 and
seqnum = 1 and status = 'F';
There is a another fun way to do this just with aggregation:
select id, max(time) as time, 'F' as status
from t
group by id
having sum(case when status = 'T' then 1 else 0 end) > 0 and
max(time) = max(case when status 'F' then time end);