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Re: ECPG and COPY FROM STDIN

From: Niels Laakmann <nielsson(at)grillen23(dot)de>
To: pgsql-interfaces(at)postgresql(dot)org
Subject: Re: ECPG and COPY FROM STDIN
Date: 2006-11-23 13:57:27
Message-ID: 20061123135805.286DA77A78@mail.toxisch.net (view raw or flat)
Thread:
Lists: pgsql-interfaces
Am heiligen Mo, 20 November 2006 06:42:23 -0500
schrieb Sean Davis <sdavis2(at)mail(dot)nih(dot)gov>:

> On Monday 20 November 2006 06:12, Niels Laakmann wrote:
> > Hey List!
> > I have to do a Benchmark-Test in C (ECPG) with and without network.
> > After reading the Performance and COPY Documentation (not correctly), I
> > wanted to Copy a File over the Network by using "COPY FROM 'filename'".
> > After some curious Problems I knew why.
> > Now I read some about "COPY FROM STDIN. But I didn't find an Example.
> > Can someone please give me an Example for that ?
> >
> > Or:
> >
> > Is there another command to insert many tuples from a Client to a
> > Server in an adequate time ?
> 
> How about here:
> 
> http://www.postgresql.org/docs/8.1/interactive/libpq-copy.html

At first thanks for this Tipp. I rewrite my Code to use Libpq now. But
the next Problem comes up:

<snap>
char textbuffer[120];

result = PQexec(connect, "COPY branches (branchid, branchname, balance,
   address) FROM STDIN WITH DELIMITER ',';");

if(PQresultStatus(result) != PGRES_COPY_IN)
   shutdown_conn(1, connect);		//my own error-handling
                                        //function

for(n=0; n < count_tupel; n++) {
   sprintf(textbuffer, "%d,text1,0,text2", n);
   if(PQputCopyData(connect, textbuffer, strlen(textbuffer) + 1) != 1)
      shutdown_conn(1, connect); 
}
   PQputCopyEnd(connect, NULL);
   PQgetResult(connect);
</snap>

If count_tupel is 1, one Tupel is inserted to the relation. If
count_tupel is greater than 1. No Tupel is inserted and I got the
Error-Message: "extra data after last expected column".
What are we doing wrong ? - Is there something wrong as I discard the
buffer ? - A Null-Termination etc. ?

The other thing is, that I've looked for some libpq-copy - examples.
But neither in the postgresql-src nor on some postgres-related
internet-pages, I found one.

Can anyone help ?
- Thanks -

Niels


> 
> Sean
> 

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Next:From: Sean DavisDate: 2006-11-23 15:39:19
Subject: Re: ECPG and COPY FROM STDIN
Previous:From: Dmitry A JackovlevDate: 2006-11-23 08:27:06
Subject: Extrach PGconn* form $dbh (perl)

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