public static bool AddStudent(Student student)
        {
            var query = Query.EQ("StuNo", student.StuNo);

            if (collection.Find(query).Count() > 0) return false;
            else
            {
                collection.Insert<Student>(student);
                return true;
            }
        }
        public static void Update(Student student)
        {
            var option = new DocumentSerializationOptions(false);
            option.SerializeIdFirst = false;

            collection.Update(new QueryDocument { { "_id", student.Id } },
                new UpdateDocument { { "$set",
                                         new BsonDocument {
                                         {"StuNo", student.StuNo },
                                         {"Name", student.Name},
                                         {"Major", student.Major},
                                         {"Class", student.Class}}
                                         }});
        }