Comparing 2 lists in Oracle - sql

Question

I have 2 lists which I need to compare. I need to find if at least one element from List A is found in List B. I know IN doesn't work with 2 lists. What are my other options?
Basically something like this :
SELECT
CASE WHEN ('A','B','C') IN ('A','Z','H') THEN 1 ELSE 0 END "FOUND"
FROM DUAL
Would appreciate any help!

Answer 1

You are probably looking for something like this. The WITH clause is there just to simulate your "lists" (whatever you mean by that); they are not really part of the solution. The query you need is just the last three lines (plus the semicolon at the end).
with
first_list (str) as (
select 'A' from dual union all
select 'B' from dual union all
select 'C' from dual
),
second_list(str) as (
select 'A' from dual union all
select 'Z' from dual union all
select 'H' from dual
)
select case when exists (select * from first_list f join second_list s
on f.str = s.str) then 1 else 0 end as found
from dual
;
FOUND
----------
1

Answer 2

In Oracle you can do:
select
count(*) as total_matches
from table(sys.ODCIVarchar2List('A', 'B', 'C')) x,
table(sys.ODCIVarchar2List('A', 'Z', 'H')) y
where x.column_value = y.column_value;

Answer 3

You need to repeat the conditions:
SELECT (CASE WHEN 'A' IN ('A', 'Z', 'H') OR
'B' IN ('A', 'Z', 'H') OR
'C' IN ('A', 'Z', 'H')
THEN 1 ELSE 0
END) as "FOUND"
FROM DUAL

Answer 4

If you are working with collection of String you can try Multiset Operators.
create type coll_of_varchar2 is table of varchar2(4000);
and:
-- check if exits
select * from dual where cardinality (coll_of_varchar2('A','B','C') multiset intersect coll_of_varchar2('A','Z','H')) > 0;
-- list of maching elments
select * from table(coll_of_varchar2('A','B','C') multiset intersect coll_of_varchar2('A','Z','H'));
Additionally:
-- union of elemtns
select * from table(coll_of_varchar2('A','B','C') multiset union distinct coll_of_varchar2('A','Z','H'));
select * from table(coll_of_varchar2('A','B','C') multiset union all coll_of_varchar2('A','Z','H'));
-- eelemnt from col1 not in col2
select * from table(coll_of_varchar2('A','A','B','C') multiset except all coll_of_varchar2('A','Z','H'));
select * from table(coll_of_varchar2('A','A','B','C') multiset except distinct coll_of_varchar2('A','Z','H'));
-- check if col1 is subset col2
select * from dual where coll_of_varchar2('B','A') submultiset coll_of_varchar2('A','Z','H','B');

Answer 5

I am trying to do something very similar but the first list is another field on the same query created with listagg and containing integer numbers like:
LISTAGG(my_first_list,', ') WITHIN GROUP(
ORDER BY
my_id
) my_first_list
and return this with all the other fields that I am already returning
SELECT
CASE WHEN my_first_list IN ('1,2,3') THEN 1 ELSE 0 END "FOUND"
FROM DUAL