OntologyDatabase.h

#ifndef ONTOLOGYDATABASE_H
#define ONTOLOGYDATABASE_H

#include <string>
#include <list>
#include <QtSql>

using namespace std;


const QString DBPATH_ONT = "../../Granular-Extractor/ont_db.sqlite";

class OntologyDatabase
{
private:
    static QSqlDatabase mOntDB;
    vector<string> vectorQuestionQuery(const string &qrStr);   

public:
    OntologyDatabase();
    void InsertionQuery(const string &qrStr);
    void QuestionQuery (const string &qrStr, string& result);  

    ~OntologyDatabase();
}; /* -----  end of class OntologyDatabase  ----- */


/********************************************************************
 *                  Class Implementation of OntologyDatabase  *
 ********************************************************************/


QSqlDatabase OntologyDatabase::mOntDB = QSqlDatabase::addDatabase("QSQLITE", "ONT_DB");

OntologyDatabase::OntologyDatabase()
{
    mOntDB.setDatabaseName (DBPATH_ONT);
        if( !mOntDB.open() ) {
            qDebug() << mOntDB.lastError();
            qFatal( "Failed to connect to database." );
            throw std::invalid_argument("Error: Invalid database");
        }
//        else { qDebug() << "Debug: Database opened." << endl; }
}

void OntologyDatabase::InsertionQuery(const string& qrStr)
{
    QSqlQuery    mLiteQr(this->mOntDB);
    mLiteQr.prepare(qrStr.c_str());
    if( !mLiteQr.exec() ) {
        qDebug() << mLiteQr.lastError();
        throw std::invalid_argument("Invalid query.");
    }
}

void OntologyDatabase::QuestionQuery(const string &qrStr, string& result)  
{
    vector<string> v_result = vectorQuestionQuery (qrStr);
    result = "";
    for(string R : v_result)
      result += (R + ", ");
    result = result.substr (0, result.size () - 2); 
}


vector<string> OntologyDatabase::vectorQuestionQuery(const string &qrStr)
{
    QSqlQuery   mLiteQr(this->mOntDB);
    mLiteQr.prepare (qrStr.c_str ());
    if( !mLiteQr.exec() ) {
        qDebug() << mLiteQr.lastError();
        throw std::invalid_argument("Invalid query.");
    }

    vector<string> resultList;
    while( mLiteQr.next() ) {
         resultList.push_back (mLiteQr.value(0).toString().toStdString());
    }
    return resultList;
}

OntologyDatabase::~OntologyDatabase()
{
}


#endif /* !ONTOLOGYDATABASE_H */