Re: create type with %type or %rowtype

On Wednesday, November 18, 2020, Post Gresql <postgresql(at)taljaren(dot)se> wrote:

>
> On 2020-11-18 17:07, Adrian Klaver wrote:
>
>
> \d cell_per
> Foreign table "public.cell_per"
> Column | Type | Collation | Nullable | Default | FDW
> options
> ----------+-------------------+-----------+----------+---------+-------------
>
> category | character varying | | | |
> cell_per | integer | | | |
> Server: test_db
>
> CREATE OR REPLACE FUNCTION public.type_test()
> RETURNS cell_per
> LANGUAGE plpgsql
> AS $function$
> DECLARE
> cp_type cell_per;
> BEGIN
> SELECT INTO cp_type * from cell_per limit 1;
> RETURN cp_type;
> END;
> $function$
>
> select * from type_test();
> category | cell_per
> ------------+----------
> H PREM 3.5 | 18
>
> You can change the RETURNS to RETURNS SETOF and return multiple rows.
>
>
> I might be stupid, but where in the document for create function does it
> say that the return type can be a table?
>
> From the doc for version 13 https://www.postgresql.org/
> docs/13/sql-createfunction.html
> *"rettype*
>
> The return data type (optionally schema-qualified). The return type can be
> a base, composite, or domain type, or can reference the type of a table
> column."
>
>

The word “composite”. Every table has an associated composite type of the
same name.

David J.