In Android Room how can I create and call a custom query

If you are using MVVM architecture with LiveData follow this method.

1. Observe the LiveData List in MoviesActivity.java

final LiveData<List<MoviesData>> viewModelData = moviesViewModel.getMoviesByGenre("comedy");
    viewModelData.observe(this, new Observer<List<MoviesData>>() {
        @Override
        public void onChanged(List<MoviesData> moviesData) {
            //Handle the Movies List here.
        }
    });

2. In MoviesViewModel.java

public LiveData<List<NotificationData>> getMoviesByGenre(String genere) {
    MoviesRepository mRepository = new MoviesRepository(application);
    LiveData<List<MoviesData>> mMoviesData = mRepository.getMoviesByGenre(genere);
    return mMoviesData;
}

3. MoviesRepository.java

private MoviesDao mMoviesDao;

//Initialize.
AppDatabase db = AppDatabase.getAppDatabase(application);
mMoviesDao = db.moviesDao();



public LiveData<List<MoviesData>> getMoviesByGenre(String genere) {
    mMovies = mMoviesDao.findMovieByGenre(genere);
    return mMovies;
}

3. In MoviesDao

@Query("SELECT * FROM movie_table ORDER BY genre")
public LiveData<List<Movies> findMovieByGenre(String genre);

So you can Observe query result in your Activity class' Observe method.