} // CreateArtistRatingService

        /// <summary>
        /// Edits an Artist Rating
        /// </summary>
        /// <param name="artistRating"></param>
        /// <returns></returns>
        public IHttpActionResult Put(ArtistRatingEdit artistRating)
        {
            if (!ModelState.IsValid)
            {
                return(BadRequest(ModelState));
            }

            var service = CreateArtistRatingService();

            if (!service.UpdateArtistRating(artistRating))
            {
                return(InternalServerError());
            }

            return(Ok());
        } // Put
        } // GetArtistRatingById

        public bool UpdateArtistRating(ArtistRatingEdit model)
        {
            using (var ctx = new ApplicationDbContext())
            {
                var entity =
                    ctx
                    .ArtistRatings
                    .Single(e => e.ArtistRatingId == model.ArtistRatingId && e.OwnerId == _userId);


                entity.Artist.CulumativeRating = entity.Artist.CulumativeRating - entity.ArtistIndividualRating;
                entity.Artist.CulumativeRating = model.ArtistIndividualRating + entity.Artist.CulumativeRating;
                entity.Artist.ArtistRating     = entity.Artist.CulumativeRating / entity.Artist.NumberOfRatings;

                entity.ArtistId = model.ArtistId;
                entity.ArtistIndividualRating = model.ArtistIndividualRating;

                return(ctx.SaveChanges() == 1);
            }
        } // UpdateArtistRating