Re: Guidance on INSERT RETURNING order

On 4/11/23 12:47, Federico wrote:
> Hello list,
>
> I have a few clarification questions regarding using insert with returning.
> The use case is SQLAlchemy development, where the orm wants to insert
> a list of rows,
> get back the generated ids, defaults, etc, and match the returned values with
> the original list of orm objects.
>
> The following assumes a table like this
>
> CREATE TABLE t(
> id SERIAL,
> data TEXT -- type here can be anything
> )
>
> On PostgreSQL, since SQLAlchemy version 1.4 (Mar 2021) this operation has used
>
> INSERT INTO t(data) VALUES ('a'), ('b'), ('c') RETURNING id
>
> but we were recently made aware that there is no guarantee on the
> order of the returned columns.

1) Because returned data in SQL is inherently unordered.

2) What would you order by, id or data or both?

> Sorry for the long email,
> Thanks
>
> Federico
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com