From: Volker Paul <vpaul@dohle.com>
To: pgsql-sql@postgresql.org
Subject: C/C++ interface
Date: Tue, 13 Feb 2001 13:10:27 +0100
Message-ID: <3A892433.879F40A0@dohle.com> (raw)
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
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To: pgsql-docs@postgresql.org
Cc: vpaul@dohle.com, pgsql-sql@postgresql.org
Subject: Re: C/C++ interface
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