Oracle query with group - sql

Question

I have a scenario where I need to fetch all the records within an ID for the same source. Given below is my input set of records
ID SOURCE CURR_FLAG TYPE
1 IBM Y P
1 IBM Y OF
1 IBM Y P
2 IBM Y P
2 TCS Y P
3 IBM NULL P
3 IBM NULL P
3 IBM NULL P
4 IBM NULL OF
4 IBM NULL OF
4 IBM Y ON
From the above settings, I need to select all the records with source as IBM within that same ID group.Within the ID group if there is at least one record with a source other than IBM, then I don't want any record from that ID group. Also, we need to fetch only those records where at least one record in that ID group with curr_fl='Y'
In the above scenario even though the ID=3 have a source as IBM, but there is no record with CURR_FL='Y', my query should not fetch the value.In the case of ID=4, it can fetch all the records with ID=4, as one of the records have value='Y'.
Also within the group which has satisfied the above condition, I need one more condition for source_type. if there are records with source_type='P', then I need to fetch only that record.If there are no records with P, then I will search for source_type='OF' else source_type='ON'
I have written a query as given below.But it's running for long and not fetching any results. Is there any better way to modify this query
select
ID,
SOURCE,
CURR_FL,
TYPE
from TABLE a
where
not exists(select 1 from TABLE B where a.ID = B.ID and source <> 'IBM')
and exists(select 1 from TABLE C where a.ID = C.ID and CURR_FL = 'Y') and
(TYPE, ID) IN (
select case type when 1 then 'P' when 2 then 'OF' else 'ON' END TYPE,ID from
(select ID,
max(priority) keep (dense_rank first order by priority asc) as type
from ( select ID,TYPE,
case TYPE
when 'P' then 1
when 'OF' then 2
when 'ON' then 3
end as priority
from TABLE where ID
in(select ID from TABLE where CURR_FL='Y') AND SOURCE='IBM')
group by ID))

Answer 1

I think you can just do a single aggregation over your table by ID and check for the yes flag as well as assert that no non IBM source appears. I do this in a CTE below, and then join back to your original table to return full matching records.
WITH cte AS (
SELECT
ID,
CASE WHEN SUM(CASE WHEN TYPE = 'P' THEN 1 ELSE 0 END) > 0
THEN 1
WHEN SUM(CASE WHEN TYPE = 'OF' THEN 1 ELSE 0 END) > 0
THEN 2
WHEN SUM(CASE WHEN TYPE = 'ON' THEN 1 ELSE 0 END) > 0
THEN 3 ELSE 4 END AS p_type
FROM yourTable
GROUP BY ID
HAVING
SUM(CASE WHEN CURR_FLAG = 'Y' THEN 1 ELSE 0 END) > 0 AND
SUM(CASE WHEN SOURCE <> 'IBM' THEN 1 ELSE 0 END) = 0
)
SELECT t1.*
FROM yourTable t1
INNER JOIN cte t2
ON t1.ID = t2.ID
WHERE
t2.p_type = 1 AND t1.TYPE = 'P' OR
t2.p_type = 2 AND t1.TYPE = 'OF' OR
t2.p_type = 3 AND t1.TYPE = 'ON';