"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Tue, Jun 7, 2022 at 1:30 PM PG Doc comments form <noreply@postgresql.org>
> wrote:
>> It looks like INSERT INTO ... RETURNING allows defining a target for the
>> returned values like SELECT ... INTO does.
> That isn't how it works. RETURNING simply turns INSERT into a result set
> producing SQL Command. And SQL doesn't have a concept of "target"
> (variables) in the sense you are thinking. pg/pgsql does, allowing result
> set data to be placed into variables.
Right. And in fact this *is* documented in the context of pl/pgsql:
https://www.postgresql.org/docs/current/plpgsql-statements.html#PLPGSQL-STATEMENTS-SQL-ONEROW
regards, tom lane