text: #ifndef __DATABASE_SERVICE_HPP_
  #define __DATABASE_SERVICE_HPP_
  
  #include<vector>
  #include<memory>
  
  namespace zpr {
  
  class DatabaseService {
      public:
          virtual std::unique_ptr<std::vector<std::string>> doWork(const std::string query) = 0;
  };
  
  class ForeignKeyViolationException : public std::exception {};
  
  }
  
  #endif //__DATABASE_SERVICE_HPP_