Re: ECPG and COPY TO STDOUT

If I use COPY TO STDOUT in an ECPG program, where does the output go?

If I use COPY TO '/tmp/foo', I get the file created, with the data in
it, but trying COPY TO STDOUT produces no output.

What I'm trying to do is to dump a table's data, and have the resulting
file owned by the application user rather than the dba user.

I would rather to not have to create the file in /tmp, copy contents, rm
/tmp file, if I don't have to.

This is the program I'm using:

#include <stdio.h>

EXEC SQL INCLUDE sqlca;
EXEC SQL WHENEVER SQLERROR sqlprint;

int main()
{

EXEC SQL BEGIN DECLARE SECTION;
char *fname = "/tmp/foo";
EXEC SQL END DECLARE SECTION;

EXEC SQL CONNECT TO test;

/* produces expected file "/tmp/foo" */
EXEC SQL COPY foo TO :fname WITH DELIMITER ',';
printf("copy to /tmp/foo : sqlca.sqlcode = %ld", sqlca.sqlcode);

/* goes nowhere (?) */
EXEC SQL COPY foo TO STDOUT WITH DELIMITER ',';
printf("copy to STDOUT : sqlca.sqlcode = %ld\n", sqlca.sqlcode);

EXEC SQL DISCONNECT;

return 0;
}

--
Edmund Bacon <ebacon(at)onesystem(dot)com>

On Thu, Apr 01, 2004 at 12:22:44PM -0700, Edmund Bacon wrote:
> If I use COPY TO STDOUT in an ECPG program, where does the output go?

Nowhere, it's discarded.

> What I'm trying to do is to dump a table's data, and have the resulting
> file owned by the application user rather than the dba user.

ecpg gets PGRES_COPY_OUT as a result from the execution and just calls
PQendcopy() without reading the data. The same happens btw with
PGRES_COPY_IN. It's working like this since the get-go in the sources I
inherited from Linux Tolke. I guess we could add this to the todo list
as a feature request.

Patches are welcome of course. :-)

Michael
--
Michael Meskes
Email: Michael at Fam-Meskes dot De
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