sql - 寻找共享相同值的键的最大组合

Question

这是我的表格:

CREATE TABLE ABC(
 key NUMBER(5), 
 val NUMBER(5)
 );

insert into ABC (key, val) values (1,1);
insert into ABC (key, val) values (1,2);
insert into ABC (key, val) values (1,3);
insert into ABC (key, val) values (2,3);
insert into ABC (key, val) values (1,4);
insert into ABC (key, val) values (2,4); 
insert into ABC (key, val) values (2,5);
insert into ABC (key, val) values (3,5);
insert into ABC (key, val) values (1,6);
insert into ABC (key, val) values (2,6);

所需输出:

我想找到共享相同值的最大键对，并将它们列出，在上面的示例中，表中出现的最大键对是(1,2)，它们共享值(3,4， 6)

Answer 1

请尝试如下:

select ab,val from (
select rank() over( order by cnt desc) rn, ab, val ,cnt
from (
select listagg(key,',')  within group(order by val) ab,val, 
count(1) over (partition by (listagg(key,',')  within group(order by val))) cnt
from abc
group by val
having count(*) > 1))
where rn = 1;