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How to use PQconsumeInput and PQisBusy correctly ?
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* How to use PQconsumeInput and PQisBusy correctly ?
@ 2005-03-13 15:56  Rodrigo Moreno <rodrigo.miguel@terra.com.br>
  0 siblings, 1 reply; 2+ messages in thread

From: Rodrigo Moreno @ 2005-03-13 15:56 UTC (permalink / raw)
  To: pgsql-interfaces

Hi all,

What's the right way to use pqconsumeinput and pqisbusy ?

The below code could be used to do that ? 

Thanks a Lot
Rodrigo Moreno


PS: Please don't worry if some code is wrong, I do not test this code yeat.


void query(PGconn *conn, const char *stmt)
{
    PGresult    *res;
    int         nFields;
    int         i,j;
    int         send;

    send = PQsendQuery(conn, stmt);
    
    if (PQconsumeInput(conn))
    {
        while (PQisBusy(conn))
        {
            printf(".");
            sleep(500);
            PQconsumeInput(conn);
        }
        
        res = PQgetResult(conn);            
            
        if (PQresultStatus(res) != PGRES_TUPLES_OK)
        {
            fprintf(stderr, "failed: %s", PQerrorMessage(conn));
            PQclear(res);
            exit_nicely(conn);
        }
        
        nFields = PQnfields(res);
        
        for (i = 0; i < nFields; i++)
            printf("%-15s", PQfname(res, i));
                
        printf("\n\n");
        
        for (i = 0; i < PQntuples(res); i++)
        {
            for (j = 0; j < nFields; j++)
                printf("%-15s", PQgetvalue(res, i, j));
                
            printf("\n");
        }
        
        PQclear(res);
    }        
}





^ permalink  raw  reply  [nested|flat] 2+ messages in thread

* Re: How to use PQconsumeInput and PQisBusy correctly ?
@ 2005-03-13 18:54  Tom Lane <tgl@sss.pgh.pa.us>
  parent: Rodrigo Moreno <rodrigo.miguel@terra.com.br>
  0 siblings, 0 replies; 2+ messages in thread

From: Tom Lane @ 2005-03-13 18:54 UTC (permalink / raw)
  To: Rodrigo Moreno <rodrigo.miguel@terra.com.br>; +Cc: pgsql-interfaces

"Rodrigo Moreno" <rodrigo.miguel@terra.com.br> writes:
> What's the right way to use pqconsumeinput and pqisbusy ?
> The below code could be used to do that ? 

It would work but it seems rather pointless; the only reason you would
use those functions is if you have something else useful to do while
waiting for the query result ... and this program structure isn't
very conducive to doing other stuff while waiting.  Usually you'd want
to have a main loop that can dispatch handling of various events, one
of them being checking for an available query result.

The whole thing is a bit of a stone-age technique anyway; if you were
thinking of starting a new program today you'd probably use threads in
preference to an event loop.

			regards, tom lane



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2005-03-13 15:56 How to use PQconsumeInput and PQisBusy correctly ? Rodrigo Moreno <rodrigo.miguel@terra.com.br>
2005-03-13 18:54 ` Tom Lane <tgl@sss.pgh.pa.us>

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