Query: vpc_empty_status

with by_empty as (
  select
    distinct vpc.vpc_id,
    case
      when s.vswitch_id is null then 'empty'
      else 'non-empty'
    end as status
  from
    alicloud_vpc as vpc
    left join alicloud_vpc_vswitch as s on vpc.vpc_id = s.vpc_id
)
select
  status,
  count(*)
from
  by_empty
group by
  status;