Group Query for oracle - oracle

Question

I have a scenario where I need to fetch all the records within an ID for the one source along with other 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 CTS NULL P
3 TCS NULL P
4 IBM NULL OF
4 CTS NULL OF
4 TCS Y ON
5 CTS NULL OF
5 TCS Y ON
From the above records, I need to select all the records with source as IBM within that same ID group and other source should be also there for the same ID along with IBM.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=1 have a source as IBM, but there is no record in that particular group with other source.So we shouldn't fetch that record with that ID.
For the record ID=3 have a source as IBM along with other sources, 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' and it have a combination of IBM with other source.For ID 5 it should not fetch as we dont have any IBM record source within that set
Also within the group which has satisfied the above condition, I need one more condition for type. if there are records with type='P', then I need to fetch only that record.If there are no records with P, then I will search for type='OF' else type='ON'
My Expected output is given below
ID SOURCE CURR_FLAG TYPE
2 IBM Y P
2 TCS Y P
4 IBM NULL OF
4 CTS NULL OF
4 TCS Y 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
exists(select 1 from TABLE B where a.ID=B.ID and a.rowid<>B.rowid and B.source<>a.source)
and exists(select 1 from TABLE C where a.ID=C.ID and C.source ='IBM')
and exists(select 1 from TABLE D where a.ID=D.ID and D.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

First, look for the ids. I would recommend:
select id
from t
group by id
having min(source) <> max(source) and -- at least two sources
sum(case when curr_flag = 'Y' then 1 else 0 end) > 0 and -- at least one Y
sum(case when source = 'IBM' then 1 else 0 end) > 0 -- IBM
To get the base rows, you can use in, exists, or join:
select t.*
from t
where id in (select id
from t
group by id
having min(source) <> max(source) and -- at least two sources
sum(case when curr_flag = 'Y' then 1 else 0 end) > 0 and -- at least one Y
sum(case when source = 'IBM' then 1 else 0 end) > 0 -- IBM
);

Answer 2

Using analytic functions you can check that there is at least one IBM in the group, at least one other source apart from IBM in the group, and at least one flag with Y in the group:
with t(id, source, curr_flag, type) as
(
select 1, 'IBM', 'Y', 'P' from dual union all
select 1, 'IBM', 'Y', 'OF' from dual union all
select 1, 'IBM', 'Y', 'P' from dual union all
select 2, 'IBM', 'Y', 'P' from dual union all
select 2, 'TCS', 'Y', 'P' from dual union all
select 3, 'IBM', NULL, 'P' from dual union all
select 3, 'CTS', NULL, 'P' from dual union all
select 3, 'TCS', NULL, 'P' from dual union all
select 4, 'IBM', NULL, 'OF' from dual union all
select 4, 'CTS', NULL, 'OF' from dual union all
select 4, 'TCS', 'Y', 'ON' from dual union all
select 5, 'CTS', NULL, 'OF' from dual union all
select 5, 'TCS', 'Y', 'ON' from dual
)
select id, source, curr_flag, type
from (select id, source, curr_flag, type,
max(case when source = 'IBM' then 1 end) over (partition by id) ibm,
max(case when source != 'IBM' then 1 end) over (partition by id) not_ibm,
max(case when curr_flag = 'Y' then 1 end) over (partition by id) flag_y
from t)
where ibm = 1
and not_ibm = 1
and flag_y = 1
order by id, source;