On Wed, 9 Dec 2020 at 10:21, electrotype <electrot...@gmail.com> wrote:
> So I'm curious. Why does order matter ? > > Dave Cramer > www.postgres.rocks > > > When you have to save multiple new entities with subentities. > > You first save all the parent entities in a single SQL batch insert, you > get the generated ids, then insert all the subentities in another single > SQL batch insert. To know which "parent id" to use for a given subentity of > the second query, you need a way to associate a generated id with the > correct parent entity. The order of the parents in their batch, and the > order of the generated ids, is the only straighforward way. > > I know all this could be made into a single SQL query, without having to > associate the generated ids to the parents manually. But sometimes you have > to fight *really *hard agains your framework or JDBC itself to write such > more complex query, where two batch inserts are very natural. > Fair enough, however the spec does not say anything about the order. In fact it doesn't even say which keys will be returned. I don't think we can make any guarantees here. Dave
