From: Tom Lane <tgl@sss.pgh.pa.us>
To: Henk Jan Barendregt <henkjan@barendregt.xs4all.nl>
Cc: pgsql-interfaces@postgreSQL.org
Subject: Re: [INTERFACES] [libpq] Return value of int
Date: Sun, 02 May 1999 12:11:56 -0400
Message-ID: <13408.925661516@sss.pgh.pa.us> (raw)
In-Reply-To: <372C1BC4.A71000FD@barendregt.xs4all.nl>
Henk Jan Barendregt <henkjan@barendregt.xs4all.nl> writes:
> How can i use libpq to return an int value when i access an INT or INT4
> value
Use atoi() ... what comes out of libpq is a character string always.
It's up to you to convert it to whatever form you want it in.
Actually, if you are really intent on avoiding the conversion step
you can use a binary cursor and get the data in whatever the backend's
internal format is. However I can't recommend this. I've found by
measurement that the conversion time is insignificant compared to the
rest of the work involved in a query, even for expensive-to-convert
datatypes like DATETIME. And for that trivial savings you expend a
lot of programming effort: you have to know what the backend's internal
format *is*, and you have to be prepared to deal with cross-machine
compatibility issues (maybe the backend is running on a machine with
different endianness than your app is ... how will you even know?),
cross-Postgres-version changes in the internal representation, yadda
yadda. Much better to take the character string.
But if you insist on doing it the hard way, read about DECLARE CURSOR
and FETCH in the manual.
regards, tom lane
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-interfaces@postgresql.org
Cc: tgl@sss.pgh.pa.us, henkjan@barendregt.xs4all.nl
Subject: Re: [INTERFACES] [libpq] Return value of int
In-Reply-To: <13408.925661516@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox