On Thu, Apr 20, 2017 at 3:17 PM, jonathan vanasco <postg...@2xlp.com> wrote:
> postgres doesn't raise an error because example_a__data does have a bar_id > -- but example_a__rollup doesn't and there's no explicit correlation in the > query. > > ​Subqueries can see all columns of the parent. When the subquery actually uses one of them it is called a "correlated subquery". See another recent question on this topic for more details: https://www.postgresql.org/message-id/20160714135233.1410.92538%40wrigleys.postgresql.org Unfortunately at present everyone here seems content answering this on the list semi-frequently instead of updating the docs and/or FAQ section of our wiki. The topic is covered (I think...) but not easily found (I failed to just now...) - and harder when you don't know what to call it in the first place. David J.
