pg.ddx.io pgsql-docs@postgresql.org mailing list archive
help / color / mirror / Atom feedC/C++ interface
6+ messages / 4 participants
[nested] [flat]
* C/C++ interface
@ 2001-02-13 12:10 Volker Paul <vpaul@dohle.com>
0 siblings, 2 replies; 6+ messages in thread
From: Volker Paul @ 2001-02-13 12:10 UTC (permalink / raw)
To: pgsql-sql@postgresql.org
Hello,
in the C interface documentation there is an example using:
res = PQexec(conn, "DECLARE mycursor CURSOR FOR select * from
pg_database");
if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
{
fprintf(stderr, "DECLARE CURSOR command failed\n");
PQclear(res);
exit_nicely(conn);
}
PQclear(res);
res = PQexec(conn, "FETCH ALL in mycursor");
...etc. So the statements are:
DECLARE mycursor CURSOR FOR select * from pg_database;
FETCH ALL in mycursor;
What's the difference between this and simply doing:
select * from pg_database;
I tried this in psql, the result seemed the same.
What I'm really using, however, is the C++ interface.
Its documentation is not yet complete.
There, too, I tried a version with and without cursor.
The result seems to be the same, but returned int is always 0
for the version without cursor, so I get no information whether
the query succeeded.
Is someone maintaining the C++ interface and its documentation?
Thanks,
Volker Paul
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: C/C++ interface
@ 2001-02-13 14:56 Bruce Momjian <pgman@candle.pha.pa.us>
parent: Volker Paul <vpaul@dohle.com>
1 sibling, 0 replies; 6+ messages in thread
From: Bruce Momjian @ 2001-02-13 14:56 UTC (permalink / raw)
To: Volker Paul <vpaul@dohle.com>; +Cc: pgsql-sql@postgresql.org
Cursors and standard queries are pretty much the same, except the cursor
can control the rows returned.
> Hello,
>
> in the C interface documentation there is an example using:
>
> res = PQexec(conn, "DECLARE mycursor CURSOR FOR select * from
> pg_database");
> if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
> {
> fprintf(stderr, "DECLARE CURSOR command failed\n");
> PQclear(res);
> exit_nicely(conn);
> }
> PQclear(res);
> res = PQexec(conn, "FETCH ALL in mycursor");
>
> ...etc. So the statements are:
>
> DECLARE mycursor CURSOR FOR select * from pg_database;
> FETCH ALL in mycursor;
>
> What's the difference between this and simply doing:
> select * from pg_database;
>
> I tried this in psql, the result seemed the same.
>
> What I'm really using, however, is the C++ interface.
> Its documentation is not yet complete.
> There, too, I tried a version with and without cursor.
> The result seems to be the same, but returned int is always 0
> for the version without cursor, so I get no information whether
> the query succeeded.
>
> Is someone maintaining the C++ interface and its documentation?
>
>
> Thanks,
>
> Volker Paul
>
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: C/C++ interface
@ 2001-02-13 15:02 Tom Lane <tgl@sss.pgh.pa.us>
parent: Volker Paul <vpaul@dohle.com>
1 sibling, 1 reply; 6+ messages in thread
From: Tom Lane @ 2001-02-13 15:02 UTC (permalink / raw)
To: Volker Paul <vpaul@dohle.com>; +Cc: pgsql-sql@postgresql.org
Volker Paul <vpaul@dohle.com> writes:
> Is someone maintaining the C++ interface and its documentation?
Not really. Feel free to step up and lend a hand ...
regards, tom lane
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: C/C++ interface
@ 2001-02-16 08:24 Volker Paul <vpaul@dohle.com>
parent: Tom Lane <tgl@sss.pgh.pa.us>
0 siblings, 2 replies; 6+ messages in thread
From: Volker Paul @ 2001-02-16 08:24 UTC (permalink / raw)
To: Tom Lane <tgl@sss.pgh.pa.us>; +Cc: pgsql-sql@postgresql.org
Tom Lane wrote:
>
> Volker Paul <vpaul@dohle.com> writes:
> > Is someone maintaining the C++ interface and its documentation?
>
> Not really. Feel free to step up and lend a hand ...
I found some functions of the C++ binding library
that are not or scarcely documented, namely:
int GetIsNull(int tup_num, int field_num);
int GetIsNull(int tup_num, const char* field_name);
int GetLine(char* string, int length);
void PutLine(const char* string);
const char* OidStatus();
int EndCopy();
I would like to complete the documentation at these points,
and maybe add some small example C++ programs.
In which form should I write the documentation and where
should I send it?
(I have no possibility at the moment to test SGML documents,
i.e. convert them to HTML.)
Regards,
Volker Paul
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: C/C++ interface
@ 2001-02-16 10:03 dev@archonet.com
parent: Volker Paul <vpaul@dohle.com>
1 sibling, 0 replies; 6+ messages in thread
From: dev@archonet.com @ 2001-02-16 10:03 UTC (permalink / raw)
To: Volker Paul <vpaul@dohle.com>; +Cc: Tom Lane <tgl@sss.pgh.pa.us>; pgsql-sql@postgresql.org
>>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<
On 2/16/01, 8:24:09 AM, Volker Paul <vpaul@dohle.com> wrote regarding Re:
[SQL] C/C++ interface:
> Tom Lane wrote:
> >
> > Volker Paul <vpaul@dohle.com> writes:
> > > Is someone maintaining the C++ interface and its documentation?
> >
> > Not really. Feel free to step up and lend a hand ...
> I would like to complete the documentation at these points,
> and maybe add some small example C++ programs.
> In which form should I write the documentation and where
> should I send it?
> (I have no possibility at the moment to test SGML documents,
> i.e. convert them to HTML.)
> Regards,
> Volker Paul
I believe there are guidelines in the developer's section of the
postgresql.org website - towards the end of the developer's docs.
- Richard Huxton
^ permalink raw reply [nested|flat] 6+ messages in thread
* Re: [SQL] C/C++ interface
@ 2001-02-16 14:40 Bruce Momjian <pgman@candle.pha.pa.us>
parent: Volker Paul <vpaul@dohle.com>
1 sibling, 0 replies; 6+ messages in thread
From: Bruce Momjian @ 2001-02-16 14:40 UTC (permalink / raw)
To: Volker Paul <vpaul@dohle.com>; +Cc: Tom Lane <tgl@sss.pgh.pa.us>; pgsql-docs
There is a libpq++.sgml. If you could send a patch against that, it
would be prefect.
> Tom Lane wrote:
> >
> > Volker Paul <vpaul@dohle.com> writes:
> > > Is someone maintaining the C++ interface and its documentation?
> >
> > Not really. Feel free to step up and lend a hand ...
>
> I found some functions of the C++ binding library
> that are not or scarcely documented, namely:
> int GetIsNull(int tup_num, int field_num);
> int GetIsNull(int tup_num, const char* field_name);
> int GetLine(char* string, int length);
> void PutLine(const char* string);
> const char* OidStatus();
> int EndCopy();
>
> I would like to complete the documentation at these points,
> and maybe add some small example C++ programs.
>
> In which form should I write the documentation and where
> should I send it?
> (I have no possibility at the moment to test SGML documents,
> i.e. convert them to HTML.)
>
> Regards,
>
> Volker Paul
>
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026
^ permalink raw reply [nested|flat] 6+ messages in thread
end of thread, other threads:[~2001-02-16 14:40 UTC | newest]
Thread overview: 6+ messages (download: mbox mbox.gz follow: Atom feed)
-- links below jump to the message on this page --
2001-02-13 12:10 C/C++ interface Volker Paul <vpaul@dohle.com>
2001-02-13 14:56 ` Bruce Momjian <pgman@candle.pha.pa.us>
2001-02-13 15:02 ` Tom Lane <tgl@sss.pgh.pa.us>
2001-02-16 08:24 ` Volker Paul <vpaul@dohle.com>
2001-02-16 10:03 ` dev@archonet.com
2001-02-16 14:40 ` Bruce Momjian <pgman@candle.pha.pa.us>
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