public bool DeleteReview(Review review)
 {
     if (databasehandler.DeleteReview(review.ID))
         return true;
     else
         return false;
 }
 // Methodes
 public bool AddReview(Review review)
 {
     if (databasehandler.AddReview(review))
         return true;
     else
         return false;
 }
 public bool DeleteReview(Review review)
 {
     if (reviewhandler.DeleteReview(review))
     {
         return true;
     }else
     {
         return false;
     }
 }
 public bool AddReview(Review review)
 {
     throw new NotImplementedException();
 }
        /// <summary>
        /// Adds a review to the database
        /// </summary>
        /// <param name="newreview"></param>
        /// <returns></returns>
        public bool AddReview(Review newreview)
        {
            try
            {
                Connect();
                cmd = new OracleCommand();
                cmd.Connection = con;
                cmd.CommandText =
                    "Insert into TREVIEW(BEOORDELING, OPMERKINGEN, VRIJWILLIGERID, HULPVRAAGID) VALUES (:NewRating, :NewComments, :NewVolunteer, :NewQuestion)";
                cmd.Parameters.Add("NewRating", newreview.Rating);
                cmd.Parameters.Add("NewComments", newreview.Comments);
                cmd.Parameters.Add("NewVolunteer", newreview.VolunteerID);
                cmd.Parameters.Add("NewQuestion", newreview.QuestionID);

                cmd.ExecuteNonQuery();
                return true;
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
                return false;
            }
            finally
            {
                Disconnect();
            }
        }