数组组合无重复

Question

我想从int[]

中进行组合

{2,4,6,7,8,10,13,15,16,18}应该提供以下结果：

2,4,6
2,4,7
2,4,8
...
15,16,18

是否可以在不使用自定义函数的情况下编写仅查询解决方案？

Answer 1

with a as (
    select i
    from unnest (array[2,4,6,7,8,10,13,15,16,18]) s(i)
)
select *
from
    a cross join a b cross join a c
where
    a < b and b < c
order by a, b, c