Re: Return SETOF or array from pl/python - Mailing list pgsql-general

From Joshua D. Drake
Subject Re: Return SETOF or array from pl/python
Date
Msg-id 42D7E576.9050001@commandprompt.com
Whole thread Raw
In response to Return SETOF or array from pl/python  (Peter Fein <pfein@pobox.com>)
Responses Re: Return SETOF or array from pl/python
List pgsql-general
Peter Fein wrote:
> Is it possible to return a SETOF text or a text[] from pl/python?
>
> I've got the following test cases:
>
> CREATE OR REPLACE FUNCTION arf()
> RETURNS text[] LANGUAGE plpythonu AS
> $$return ["one", "two", "three"]$$;
>
> SELECT arf();
>
> ERROR:  missing dimension value
>
> CREATE OR REPLACE FUNCTION arf2()
> RETURNS text[] LANGUAGE plpythonu AS
> $$return '{"one", "two", "three"}'$$;
>
> SELECT arf2();
>
>        arf2
> -----------------
>  {one,two,three}
> (1 row)
>
> CREATE OR REPLACE FUNCTION srf()
> RETURNS SETOF text LANGUAGE plpythonu AS
> $$return ["one", "two", "three"]$$;
>
> SELECT * FROM srf();
>
>             srf
> -------------------------
>  ['one', 'two', 'three']
> (1 row)
>
> SELECT srf();
> Never returns.

I am not an everyday python programmer but I am pretty sure that you are
trying to return a list in arf(). You can't return a list you have to
return the array type which is why arf2 works.

The reasons srf works is because you are just returning text in general
regardless that it is formatting to a list.

Sincerely,

Joshua D. Drake


>
> I can obviously use something like arf2 (manually stringifying w/i
> python) but this seems ugly.  I'd really prefer to return a set, rather
> than an array.
>


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