Re: PL/pgSQL PERFORM with CTE - Mailing list pgsql-hackers

From Merlin Moncure
Subject Re: PL/pgSQL PERFORM with CTE
Date
Msg-id CAHyXU0zAyGi5Jp-X_NrDCW0c4cxgk3LzFV08qbeq9D_Qf-sUew@mail.gmail.com
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In response to Re: PL/pgSQL PERFORM with CTE  (Pavel Stehule <pavel.stehule@gmail.com>)
List pgsql-hackers
On Tue, Aug 20, 2013 at 7:44 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
>
>
>
> 2013/8/20 Merlin Moncure <mmoncure@gmail.com>
>>
>> On Tue, Aug 20, 2013 at 7:25 AM, Andres Freund <andres@2ndquadrant.com>
>> wrote:
>> > On 2013-08-20 14:15:55 +0200, David E. Wheeler wrote:
>> >> Hi Pavel,
>> >>
>> >> On Aug 20, 2013, at 2:11 PM, Pavel Stehule <pavel.stehule@gmail.com>
>> >> wrote:
>> >>
>> >> >>     david=# DO $$
>> >> >>     david$# BEGIN
>> >> >>     david$#     WITH now AS (SELECT now())
>> >> >>     david$#     PERFORM * from now;
>> >> >>     david$# END;
>> >> >>     david$# $$;
>> >> >>     ERROR:  syntax error at or near "PERFORM"
>> >> >>     LINE 4:     PERFORM * from now;
>> >> >>                 ^
>> >> >> Parser bug in PL/pgSQL, perhaps?
>> >> >
>> >> > no
>> >> >
>> >> > you cannot use a PL/pgSQL statement inside SQL statement.
>> >>
>> >> Well, there ought to be *some* way to tell PL/pgSQL to discard the
>> >> result. Right now I am adding a variable to select into but never otherwise
>> >> use. Inelegant, IMHO. Perhaps I’m missing some other way to do it?
>> >>
>> >> If so, it would help if the hint suggesting the use of PERFORM pointed
>> >> to such alternatives.
>> >
>> > Not that that's elegant but IIRC PERFORM (WITH ...) ought to work. I
>> > don't think the intermingled plpgsql/sql grammars allow a nice way right
>> > now.
>>
>> I think the way forward is to remove the restriction such that data
>> returning queries must be PERFORM'd
>
>
> I disagree, current rule has sense.

Curious what your thinking is there.

merlin



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