PostgreSQL connection program crash

[Sibyx]

Hi guys,
I'm trying to create connection to Postgre SQL database using libpq library. That's my code:
postgreconn.h"
@#include "libpq-fe.h"
#include <stdio.h>
#include <stdlib.h>
#include <QtCore>
class PostgreConn
{
public:
PostgreConn(QString host, QString port, QString user, QString password, QString database);
void close();
~PostgreConn();
private:
PGconn *conn;
PGresult *res;
};@
postgreconn.cpp:
@#include "postgreconn.h"
PostgreConn::PostgreConn(QString host, QString port, QString user, QString password, QString database)
{
conn = PQconnectdb(QString("hostaddr = '" + host + "' port = '" + port + "' dbname = '" + database + "' user = '" + user + "' password = '" + password + "' connect_timeout = '10'").toAscii().data());
if (PQstatus(conn) != CONNECTION_OK) {
fprintf(stderr, "Connection to database failed: %s",PQerrorMessage(conn));
}
else {
qDebug() << "Connected";
}
}

void PostgreConn::close()
{
this->~PostgreConn();
}

PostgreConn::~PostgreConn()
{
PQfinish(conn);
}@
and part of ui constructor:
@qDebug() << "PostgreSQL Inicialization starts";
PostgreConn db("192.168.1.30", "5432", "postgres", "pass", "test");
db.close();@
Now, when I compiled and executed my program, it crushed and I have output:
Starting C:\Users\magia\Qt\DatabaseExporter\debug\DatabaseExporter.exe...
PostgreSQL Inicialization starts
The program has unexpectedly finished.
C:\Users\magia\Qt\DatabaseExporter\debug\DatabaseExporter.exe exited with code -1073740940
I have Windows 7 64bit (if it helps) and I'm using msvc2010 compiler. I don't know where is mistake. Can you help me with it? Thanks for help.

[Sibyx]

Solved, I had bad declaration of object PostgreConn. I fix it:
@qDebug() << "PostgreSQL Inicialization starts";
PostgreConn *db;
db = new PostgreConn("192.168.1.30", "5432", "postgres", "pass", "test");
db->close();@