I am using QT commercial edition and i installed my OCI driver to access ORACLE db.
Qt Code: 
  1. static int cCount = 0;
  2.  
  3.  
  4.     QSqlError err;
  5.     QSqlDatabase db = QSqlDatabase::addDatabase(driver, QString("Connection%1").arg(++cCount));
  6.     //db.setDatabaseName(dbName);
  7.     db.setHostName(host);
  8.     db.setPort(port);
  9.     if (!db.open(user, passwd)) {
  10.         err = db.lastError();
  11.         db = QSqlDatabase();
  12.         QSqlDatabase::removeDatabase(QString("Connection%1").arg(cCount));
  13.     }
  14. 	else{
  15. 		conName.append(QString::number(cCount,10));
  16. 		  QSqlQuery query;
  17. 		   query.prepare("INSERT INTO person (id, forename, surname) "
  18.                    "VALUES (:id, :forename, :surname)");
  19.      query.bindValue(":id", 10);
  20.      query.bindValue(":forename", "Bart");
  21.      query.bindValue(":surname", "Simpson");
  22. if(!query.exec())//;
  23. 		{
  24. 			QSqlError err1=query.lastError();
  25. 			QMessageBox::information(this,"Hi",err1.text());
  26. 		}
To copy to clipboard, switch view to plain text mode 
This is the method am using to create connection with my Db and immediately executing the sql query.Using above method i am able to connect with oracle Db with OCI driver and while executing sql query i am receiving error,which states that "Driver not loaded Driver not loaded".

what is the problem? can any one help me....

thanks