QPSQL unable to COPY large files

[david_qt]

Hello.
I'm trying to make a function for create a large table from file using COPY.
My function create the *.csv file properly.
After, my function generate the query, who calls to a postgres function that uses COPY command.

This is the postgres function:

CREATE OR REPLACE FUNCTION importar_copy(
    _nombretabla character varying,
    _ruta character varying)
  RETURNS boolean AS
$BODY$
DECLARE
texto text;
BEGIN
	texto = FORMAT ('COPY %I FROM %s DELIMITER %s NULL AS ''NULL''', _nombretabla, quote_literal(_ruta), quote_literal(chr(9)));
	execute (texto);
	raise notice '%',texto;
	return true;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;

Well, it's very curious (and very annoying) to see that looks as if the query executed from my application isn't not able to read so a large file, and looks as if it stop to read in any point of the file.
I think that the file and the query is OK because if I copy the query generate in Qt and I run it in pgAdmin, there are no problem.

This is the snippet of Qt where I buid the file and after I try to execute the query:

QTextStream tConceptos;
QFile file;
 if (tipo == SIMPLIFICADO)
 {
     file.setFileName("conceptos.csv");
     file.open(QIODevice::WriteOnly | QIODevice::Text);
     tConceptos.setDevice(&file);
     tConceptos.setCodec("UTF-8");
 }
---------------
(feeding the QTextStream)
tConceptos<<"field"<<"\t"<<"field"<<"\t"<<......."\n";
----------------
 QString cadenaimportar = "SELECT importar_copy('" + tabla + "','/path/conceptos.csv',)";
 QSqlQuery consulta(db);
 if(consulta.prepare(cadenaimportar))
 {
     consulta.exec();
 }
qDebug()<<consulta.lastError()<<"--"<<consulta.lastQuery();
file.close();

I would like to know if I am doing anything wrong, or it is a limitation of Qt (QPSQL driver?) because I think that itsn't a problem of the csv files or queries, because I can execute the same queries without problems in pgAdmin.

[david_qt]

Well, I have discovered my problem.
I was trying to read the file before closing it:

QString cadenaimportar = "SELECT importar_copy('" + tabla + "','/path/conceptos.csv',)";
 ......
file.close();

And it would be:

file.close();
 QString cadenaimportar = "SELECT importar_copy('" + tabla + "','/path/conceptos.csv',)";
 QSqlQuery consulta(db);
 if(consulta.prepare(cadenaimportar))
 {
     consulta.exec();
 }
qDebug()<<consulta.lastError()<<"--"<<consulta.lastQuery();