* @brief Returns the variant as a double if the variant has userType() QMetaType::Double, QMetaType::Float, QMetaType::Bool, QMetaType::QByteArray, QM

* @brief Returns the variant as an int if the variant has userType() QMetaType::Int, QMetaType::Bool, QMetaType::QByteArray, QMetaType::QChar, QMetaTy

< @brief // Executte the query

* @brief toJson Convert the model data (its property name and value pairs) in JSON format * @return QJsonObject: A JSON version of the model

* @brief Returns the variant as a long long int if the variant has userType() QMetaType::LongLong, QMetaType::Bool, QMetaType::QByteArray, QMetaType::

* @brief Returns the variant as a QString if the variant has userType() QMetaType::QString, QMetaType::Bool, QMetaType::QByteArray, QMetaType::QChar,

* @brief Destructor */