#include <QtCore>
#include <QtSql>

void createTable(QSqlDatabase *pDb) {
   if (pDb) {
      QSqlQuery createTable("CREATE TABLE TESTTABLE (ID NUMBER(10) NOT NULL, EventDate DATE)");
      if (createTable.exec())
         qDebug() << "Successfully created table.";
      else
         qDebug() << "Failed to create table.";
   }
}

void insertRecords(QSqlDatabase *pDb, const QDateTime &dt) {
   if (pDb) {
      for (int i = 0; i < 5; i++) {
         QSqlQuery insertQuery;
         insertQuery.prepare("INSERT INTO TESTTABLE VALUES (?, ?)");
         insertQuery.bindValue(0, i);
         insertQuery.bindValue(1, dt);
         if (insertQuery.exec())        
            qDebug() << "Successfully inserted record.";
         else
            qDebug() << "Failed to insert record.";
      }
   }
}

void findRecords(QSqlDatabase *pDb, const QDateTime &startDate, const QDateTime &endDate) {
   QSqlQuery query;
   query.prepare("SELECT * FROM TESTTABLE WHERE EventDate >= ? AND EventDate <= ?");
   query.addBindValue(startDate);
   query.addBindValue(endDate);
   if (query.exec()) {
      int count = 0;
      while (query.next()) {
         qDebug() << "Found record: " << query.value(0).toString();
         count++;
      }

      if (count == 0)
         qDebug() << "No results found.";
   }
}

int main(int argc, char ** argv) {
   QSqlDatabase db = QSqlDatabase::addDatabase("QOCI");
   db.setHostName("<HOST>"); // change to oracle 10g host
   db.setPort(1521); // port
   db.setDatabaseName("<SID>"); // SID
   db.setUserName("<USERNAME>");
   db.setPassword("<PASSWORD>");
   if (db.open()) {
      QDateTime currentDate = QDateTime::currentDateTime();
      QDateTime endDate = currentDate.addDays(1);
      createTable(&db);
      insertRecords(&db, currentDate.toUTC());

      // 1st attempt, query for records in between the two date times. Will return 0 records.
      QDateTime startDate = currentDate.addSecs(-60); // query start date 1 minute before current time
      findRecords(&db, startDate.toUTC(), endDate.toUTC());
      
      // 2nd attempt, query for records in between the two date times but set start date 1 hour back. Will return 5 records.
      QDateTime startDate2 = startDate.addSecs(-3600); // query start date 1 hour before original start date
      findRecords(&db, startDate2.toUTC(), endDate.toUTC());
   }

   return 0;
}