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Message-ID: <4DE79F23.3060204@esilo.com>
Date: Thu, 02 Jun 2011 10:33:07 -0400
From: Andrew Chernow <ac@esilo.com>
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To: Pavel Golub <pavel@gf.microolap.com>
CC: Pavel Golub <pavel@microolap.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>,
	pgsql-interfaces@postgresql.org
Subject: Re: PQdeleteTuple function in libpq
References: <147534417.20110601184310@gf.microolap.com>
	<4DE6A5B7.2070700@esilo.com>
	<707574086.20110602112826@gf.microolap.com>
	<4DE79A58.4010608@esilo.com>
In-Reply-To: <4DE79A58.4010608@esilo.com>
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>> AC> IMHO, this should be handled by the application. You could track
>> tuples
>> AC> removed in an int[] or copy the result set into an application
>> defined
>> AC> array of C structures. I've always been under the impression that
>> AC> PGresult objects are immutable once delivered to the application.
>>
>>
>> Andrew, why we have PQmakeEmptyPGresult, PQcopyResult,
>> PQsetResultAttrs, PQsetvalue and PQresultAlloc in this case? Of course
>> there's no big deal with their absence but let's be consistent.
>>
>
> I'm not entirely sure what you are trying to do, but can't you use
> PQmakeEmptyPGresult, PQsetResultAttrs and PQsetvalue to construct a
> result that excludes the tuples you don't want followed by a
> PQclear(initial_result)?
>

Actually the best solution would be to call PQcopyResult with all 
PG_COPYRES_XXX flags enabled except PG_COPYRES_TUPLES.  Now call 
PQsetvalue for each tuple you want to add.

-- 
Andrew Chernow
eSilo, LLC
global backup
http://www.esilo.com/