/// <summary>
/// Inserts new rating and calculates rating for the movie. There is no changing of this data, therefore only insert exists.
/// </summary>
/// <param name="rating"></param>
/// <returns></returns>
public decimal InsertMovieRating(Rating rating)
{
rating.Movie = null;
movieDB.Rating.Add(rating);
movieDB.SaveChanges();
Dictionary <int, int> ratings = movieDB.SqlQuery <int, int>(System.Data.CommandType.Text, "SELECT SUM(Rating) as Rating,COUNT(MovieID) as Movies FROM Rating WHERE MovieID = " + rating.MovieId, "Rating", "Movies") as Dictionary <int, int>;
Movie movie = movieDB.Movie.Find(rating.MovieId);
movie.Rating = (decimal)ratings.FirstOrDefault().Key / (decimal)ratings.FirstOrDefault().Value;
movieDB.Entry(movie).State = EntityState.Modified;
movieDB.SaveChanges();
return(movie.Rating);
}