Re: Using FETCH ALL with descriptor areas

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(dot)rost(at)noaa(dot)gov
http://www.nohrsc.noaa.gov
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