pc-system/databasemanager.h

#ifndef DATABASEMANAGER_H
#define DATABASEMANAGER_H
#include <QSqlDatabase>

class DatabaseManager {
   public:
    static DatabaseManager& getInstance();
    QSqlDatabase& getDatabase();

   private:
    DatabaseManager();
    ~DatabaseManager();
    DatabaseManager(const DatabaseManager&) = delete;
    DatabaseManager& operator=(const DatabaseManager&) = delete;
    QSqlDatabase db;
};

#endif  // DATABASEMANAGER_H