Question

Imagine we have a simple table

create table a (id serial, data text);

and the following function:

create or replace function f()
returns SETOF int As
$BODY$
DECLARE
  l_arr int[];
BEGIN

  insert into a(data) 
  values ('a') 
  returning array_agg(data) into l_arr; --THIS DOES NOT WORK

  RETURN l_arr;

END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE SECURITY DEFINER
  COST 100

How one may gather inserted values into an array in the same SQL statement?

Answer 1

It appears, that it is possible to use RETURN QUERY without intermediate array:

create or replace function f()
returns SETOF int As
$BODY$
BEGIN
  RETURN QUERY
  insert into a(data) 
  values ('a') 
  returning id;
END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE SECURITY DEFINER
  COST 100