Athena: Reference left-hand row in right-hand subquery? (correlated subquery, CROSS JOIN LATERAL)

0

I have a usecase where I need to support recursive relationship fetching, with a possible LIMIT clause on each depth of relationship.

Something like:

SELECT ... FROM artists LIMIT 5
for artist in artists:

    SELECT ... FROM albums WHERE artist_id = artist.id LIMIT 3
    for album in albums:

        SELECT ... FROM tracks WHERE album_id = albums.id LIMIT 2

In Postgres/MySQL etc, you can do this with LATERAL/CROSS APPLY.

select *
from
  lateral (
    select ...
    from `Artist`
    limit 5
  ) as `Artist`,

  lateral (
    select ...
    from `Album`
    where `Artist`.`ArtistId` = `Album`.`ArtistId`
    limit 3
  ) as `Album`

Athena says that it supports CROSS JOIN LATERAL:

However if you try to use this with a correlated subquery, it wigs out Is there any way to emulate the behavior of LATERAL/CROSS APPLY with the variant of SQL that Athena V2 supports?

  • Enter image description here
질문됨 2년 전67회 조회
답변 없음

로그인하지 않았습니다. 로그인해야 답변을 게시할 수 있습니다.

좋은 답변은 질문에 명확하게 답하고 건설적인 피드백을 제공하며 질문자의 전문적인 성장을 장려합니다.

질문 답변하기에 대한 가이드라인

관련 콘텐츠