[GENERAL] pl/python composite type array as input parameter

[Filipe Pina]

Hello,

I'm building an app in Django and I want to have some functions 
directly in postgres. I'd prefer to use pl/python for the functions as 
it'd look better in Django migration files (python code within python 
code, instead of using PLPGSQL).

But one of the functions I need to create needs to accept an array of 
records.

The example of what I'm trying to do:

CREATE TABLE employee (
 name text,
 salary integer,
 age integer
);

CREATE OR REPLACE FUNCTION testp(e employee)
 RETURNS integer
AS $$
 plpy.notice('type', e.__class__)
$$ LANGUAGE plpythonu;

select testp(
       ('asd',10,10)::employee
       );

CREATE OR REPLACE FUNCTION testp2(es employee[])
 RETURNS integer
AS $$
 for e in es:
   plpy.notice('here', e.__class__)
$$ LANGUAGE plpythonu;

select testp2(
       ARRAY[
       ('asd',10,10)::employee
       ]::employee[]
       );

Running this .sql yelds:

CREATE TABLE
CREATE FUNCTION
psql:nfun.sql:15: NOTICE: ('type', <type 'dict'>)
CONTEXT: PL/Python function "testp"
testp 
-------
     
(1 row)

CREATE FUNCTION
psql:nfun.sql:28: NOTICE: ('here', <type 'str'>)
CONTEXT: PL/Python function "testp2"
testp2 
--------
      
(1 row)

so testp() that receives a single "employee" has the correct cast to 
"employee" and yelds type __dict__ as expected.

testp2() that receives an array of "employee", yelds type __str__ for 
each element of the array...

Should I declare the function some other way?
Is there any way I can force the cast on each element? I found some 
hits on google on *_fromDatum() internal functions but I didn't 
understand how/if I can call them explicitly..

Thanks,
Filipe