Find parent id when all children share the same value - sql

Question

I have some data that looks a little like this
Table C
id | end_time
-------------
1 '2019-01-01'
2 '2020-01-01'
3 '2019-07-01'
Table F
id | parent_id
12 | 1
13 | 1
21 | 2
22 | 2
31 | 3
32 | 3
33 | 3
34 | 3
Table oui
rel_id | Product Version
1 '2'
12 '2'
13 '1'
2 '1'
21 '2'
22 '1'
3 '2'
31 '1'
32 '1'
33 '1'
34 '1'
Data relationship:
c.id = f.parent_id
c.id or f.id = oui.rel_id
What I'm trying to find is where the rel_id for C in table oui is the parent's product version is 2, but ALL children are version 1.
I found a similar question over here: Find ID of parent where all children exactly match but couldn't quite adapt it to this use case.
Expected result:
c.id
----
3
Reasoning: Both c.id 1/2 have children which have at least 1 item in product version 2.

Answer 1

Try this below logic-
DEMO HERE
SELECT ID FROM C
WHERE ID NOT IN
(
SELECT C.ID
FROM C
INNER JOIN F ON C.id = F.parent_id
INNER JOIN oui ON F.ID = Oui.rel_id
WHERE C.ID = CAST(oui.Product_Version AS INT)
-- by default your column "Product Version" should be INT in table oui
)
The issue you mentioned in the below comment, you can try this opposite conversion as below-
SELECT ID FROM C
WHERE ID NOT IN
(
SELECT C.ID
FROM C
INNER JOIN F ON C.id = F.parent_id
INNER JOIN oui ON F.ID = Oui.rel_id
WHERE CAST(C.ID AS VARCHAR) = oui.Product_Version
)

Answer 2

You want to get C entries with product version = 2 for which exists F entries with product version = 1 and not exist F entries with product version <> 1.
I don't know why there is a separate table OUI at all. One would expect the product version to be a mere column in the tables C and F instead.
So, let's use two with clauses to get to better tables :-)
with better_c as (select c.*, oui.product_version from c join oui on oui.rel_id = c.id)
, better_f as (select f.*, oui.product_version from f join oui on oui.rel_id = f.id)
The real query can then be written with INTERSECT and EXECPT:
with ...
select id from better_c where product_version = 2
intersect
select parent_id from better_f where product_version = 1
except
select parent_id from better_f where product_version <> 1;
The same with [NOT] EXISTS:
with ...
select id
from better_c
where product_version = 2
and exists
(select null from better_f where product_version = 1 and parent_id = better_c.id)
and not exists
(select parent_id from better_f where product_version <> 1 and parent_id = better_c.id);
The same with [NOT] IN:
with ...
select id
from better_c
where product_version = 2
and id in (select parent_id from better_f where product_version = 1)
and id not in (select parent_id from better_f where product_version <> 1);

Answer 3

Try This:
select
t1.id
from c "t1"
inner join oui "t2" on t2.rel_id=t1.id
where t2.product_version='2' -- product_version for Parent
and
(select
count(*)
from f "t3"
inner join oui t4 on t4.rel_id=t3.id
where t4.product_version !='1' -- product_version for Child
and t3.parent_id=t1.id
)=0
Note: Above query will work perfectly if the ID in table C and ID in table F is not same and rel_id column in table oui is having unique values.