From: andy rost <andy.rost@noaa.gov>
To: Joachim Wieland <joe@mcknight.de>
Cc: pgsql-interfaces@postgresql.org
Subject: Re: Using FETCH ALL with descriptor areas
Date: Wed, 02 Aug 2006 13:07:34 -0500
Message-ID: <44D0E9E6.1010009@noaa.gov> (raw)
In-Reply-To: <20060801073948.GA2236@mcknight.de>
References: <44CA74FA.5010305@noaa.gov>
<20060801073948.GA2236@mcknight.de>
Worked like a charm. And its fast. Thanks Joachim
Joachim Wieland wrote:
> On Fri, Jul 28, 2006 at 03:35:06PM -0500, andy rost wrote:
>
>>Is it possible, in ECPG, to use FETCH ALL with descriptor areas? If so,
>>can anyone provide a simple example. If not, does anyone have a get
>>around. We've found FETCH NEXT to be pretty expensive when selecting
>>even a modest number of tuples.
>
>
> I don't know if it is what you're looking for nor if it is faster at all but
> I attach an example with descriptors and auto-allocation.
>
>
> Joachim
>
>
>
> ------------------------------------------------------------------------
>
> #include <stdio.h>
> exec sql include sqlca;
> #include <stdlib.h>
> exec sql include ../regression;
>
> int main(void)
> {
> exec sql begin declare section;
> int *ip1=0;
> char **cp2=0;
> int *ipointer1=0;
> int *ipointer2=0;
> int colnum;
> exec sql end declare section;
> int i;
>
> ECPGdebug(1, stderr);
>
> exec sql whenever sqlerror do sqlprint();
> exec sql connect to REGRESSDB1;
>
> exec sql create table test (a int, b text);
> exec sql insert into test values (1, 'one');
> exec sql insert into test values (2, 'two');
> exec sql insert into test values (NULL, 'three');
> exec sql insert into test values (4, 'four');
> exec sql insert into test values (5, NULL);
> exec sql insert into test values (NULL, NULL);
>
> exec sql allocate descriptor mydesc;
> exec sql select * into descriptor mydesc from test;
> exec sql get descriptor mydesc :colnum=COUNT;
> exec sql get descriptor mydesc value 1 :ip1=DATA, :ipointer1=INDICATOR;
> exec sql get descriptor mydesc value 2 :cp2=DATA, :ipointer2=INDICATOR;
>
> printf("Result (%d columns):\n", colnum);
> for (i=0;i < sqlca.sqlerrd[2];++i)
> {
> if (ipointer1[i]) printf("NULL, ");
> else printf("%d, ",ip1[i]);
>
> if (ipointer2[i]) printf("NULL, ");
> else printf("'%s', ",cp2[i]);
> printf("\n");
> }
> ECPGfree_auto_mem();
> printf("\n");
>
> exec sql deallocate descriptor mydesc;
> exec sql rollback;
> exec sql disconnect;
> return 0;
> }
--
--------------------------------------------------------------------------------
Andrew Rost
National Operational Hydrologic Remote Sensing Center (NOHRSC)
National Weather Service, NOAA
1735 Lake Dr. West, Chanhassen, MN 55317-8582
Voice: (952)361-6610 x 234
Fax: (952)361-6634
andy.rost@noaa.gov
http://www.nohrsc.noaa.gov
--------------------------------------------------------------------------------
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To: pgsql-interfaces@postgresql.org
Cc: andy.rost@noaa.gov, joe@mcknight.de
Subject: Re: Using FETCH ALL with descriptor areas
In-Reply-To: <44D0E9E6.1010009@noaa.gov>
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