检查 arrays 的交点

Question

我的表如下所示：

ID	top_id	name_important	姓名	另一个列
111			[AAA，BBB]	null
222	111	[AAA]		X

我想检查的是top_id和name_important不为空。 并且数组name_important中的值位于基于top_id的数组name中（那些 arrays 可能为空或可能不存在）。 在这种情况下， id 222 和 111 之间存在关系，因为id 222 在top_id列中有 111。 我想返回true或false 。 你可以帮帮我吗？

我想使用 case when 子句，因为我还有其他情况要包括在内，如下所示：

with test as (
  select 111 as id, null as top_id, null as name_important, ["AAA", "BBB"] as name, null as another_column union all
  select 222, 111, ["AAA"], null, X
)

select id,
case when another_column is not null then true
when (question in the topic) then true
else false end result
from test

Answer 1

也许这样的东西可能适合：

with test as (
  select 111 as id, null as top_id, null as name_important, ["AAA", "BBB"] as name, null as another_column union all
  select 222, 111, ["AAA"], null, "X"
)
select 
  id,
  case 
    when another_column is not null then true
    when intersected then true
    else false
  end result
from (
  select test.*, ifnull(intersected, false) as intersected
  from test
  left join (
    select secondary.id, true as intersected
    from (
      select test.id, name
      from test, test.name as name
    ) as main
    join (
      select test.id, test.top_id, name_important
      from test, test.name_important as name_important
    ) as secondary
    on main.id = secondary.top_id and main.name = secondary.name_important
  ) using (id)
)

Answer 2

从您的示例中不清楚您是否需要数组中的所有值都匹配或任何值。 如果你想要任何价值，那么：

with test as (
  select 111 as id, null as top_id, null as name_important, ['AAA', 'BBB'] as name union all
  select 222, 111, ['AAA'], null
)
select t2.*, t1.name
from test t1 join
     test t2
     on t1.top_id = t2.id
where t1.name_important is not null and
      exists (select 1
              from unnest(t2.name) n1 join 
                   unnest(t1.name_important) n2
                   on n2 = n1
             )

如果都需要匹配：

with test as (
  select 111 as id, null as top_id, null as name_important, ['AAA', 'BBB'] as name union all
  select 222, 111, ['AAA'], null
)
select t1.*, t2.name
from test t1 join
     test t2
     on t1.top_id = t2.id
where t1.name_important is not null and
      not exists (select 1
                  from unnest(t1.name_important) n1 left join
                       unnest(t2.name) n2  
                       on n2 = n1
                  where n2 is null
                 );