Re: Return values ???

In fact I think there are no so big diference. FOREACH as I understand does the same steps as the programmer when he writes OPEN .. WHILE .. check for NOTDOUND. But, Jonathan, we can't pass any parameters to procedure with FOREACH. Best Regards, Octav On Tue, Aug 10, 1999 at 07:11:58AM -0400, Barnes, Steve (IFMG) wrote: > Jonathan, > > I am curious as to why a FOREACH is considered better than OPEN, WHILE, > FETCH, CLOSE. I always thought that for large numbers of reads, the overhead > of a FOREACH instead of the alternative had performance impacts. This was > the thought a few years ago, and maybe I am behind the times! > > Can you please clarify this for me please. > > Thanks > > Steve > > -----Original Message----- > From: Jonathan Leffler [mailto:jleffler@earthlink.net] > Sent: Monday, August 09, 1999 11:59 PM > To: informix-list@iiug.org > Subject: Re: Return values ??? > > Octav Chiriac wrote: > > [...various variations on PREPARE and DECLARE...] > > OPEN qCursorName USING var1, var2 > > > > WHILE TRUE > > FETCH qCursorName INTO result1, result2 > > IF sqlca.sqlcode == NOTFOUND THEN > > EXIT WHILE > > END IF > > > > -- DO SOMETHING WITH YOUR results > > > > END WHILE > > > > CLOSE qCursorName > > > > FREE ... stuff > > It is much better to use a FOREACH loop because it is more > reliable: > > PREPARE p_stmt FROM "EXECUTE PROCEDURE theprocedure(?,?)" > DECLARE c_stmt FROM p_stmt > > FOREACH c_stmt USING var1, var2 INTO result1, result2 > ...Do Something With Your Results... > END FOREACH > > FREE c_stmt > FREE p_stmt > > Don't forget to release both the statement and the cursor. > And > do use FOREACH rather than ever writing out the loop from > spare > parts (OPEN, WHILE, FETCH, CLOSE). > > This has been available since at latest the 4.14/6.02 > release pair, > and possibly as early as the 4.12/6.00 release pair. > > -- > Jonathan Leffler (jleffler@informix.com, > jleffler@earthlink.net) > Guardian of DBD::Informix v0.60 -- see > http://www.perl.com/CPAN > #include <disclaimer.h> -- Octav Chiriac Phone: (373) 2 22 99 67 NetInfo S.R.L. Fax: (373) 2 21 36 59 Chisinau (373) 2 22 84 88 Moldova, Republic of mailto:com@netinfo-moldova.com

You can pass parameters with FOREACH: FOREACH qCursorName USING var1, var2 INTO result1, result2 DO SOMETHING END FOREACH Octav Chiriac wrote<7op54c$pgr$1@news.xmission.com>... > >In fact I think there are no so big diference. FOREACH as I understand >does the same steps as the programmer when he writes OPEN .. WHILE .. >check for NOTDOUND. >But, Jonathan, we can't pass any parameters to procedure >with FOREACH. > >Best Regards, >Octav > >On Tue, Aug 10, 1999 at 07:11:58AM -0400, Barnes, Steve (IFMG) wrote: >> Jonathan, >> >> I am curious as to why a FOREACH is considered better than OPEN, WHILE, >> FETCH, CLOSE. I always thought that for large numbers of reads, the overhead >> of a FOREACH instead of the alternative had performance impacts. This was >> the thought a few years ago, and maybe I am behind the times! >> >> Can you please clarify this for me please. >> >> Thanks >> >> Steve >> >> -----Original Message----- >> From: Jonathan Leffler [mailto:jleffler@earthlink.net] >> Sent: Monday, August 09, 1999 11:59 PM >> To: informix-list@iiug.org >> Subject: Re: Return values ??? >> >> Octav Chiriac wrote: >> > [...various variations on PREPARE and DECLARE...] >> > OPEN qCursorName USING var1, var2 >> > >> > WHILE TRUE >> > FETCH qCursorName INTO result1, result2 >> > IF sqlca.sqlcode == NOTFOUND THEN >> > EXIT WHILE >> > END IF >> > >> > -- DO SOMETHING WITH YOUR results >> > >> > END WHILE >> > >> > CLOSE qCursorName >> > >> > FREE ... stuff >> >> It is much better to use a FOREACH loop because it is more >> reliable: >> >> PREPARE p_stmt FROM "EXECUTE PROCEDURE theprocedure(?,?)" >> DECLARE c_stmt FROM p_stmt >> >> FOREACH c_stmt USING var1, var2 INTO result1, result2 >> ...Do Something With Your Results... >> END FOREACH >> >> FREE c_stmt >> FREE p_stmt >> >> Don't forget to release both the statement and the cursor. >> And >> do use FOREACH rather than ever writing out the loop from >> spare >> parts (OPEN, WHILE, FETCH, CLOSE). >> >> This has been available since at latest the 4.14/6.02 >> release pair, >> and possibly as early as the 4.12/6.00 release pair. >> >> -- >> Jonathan Leffler (jleffler@informix.com, >> jleffler@earthlink.net) >> Guardian of DBD::Informix v0.60 -- see >> http://www.perl.com/CPAN >> #include <disclaimer.h> > >-- >Octav Chiriac Phone: (373) 2 22 99 67 >NetInfo S.R.L. Fax: (373) 2 21 36 59 >Chisinau (373) 2 22 84 88 >Moldova, Republic of mailto:com@netinfo-moldova.com