public ProfessorModel GetProfessorUser(string username)
        {
            var queryString = string.Format("SELECT Professor_Name, Professor_ID, username, password FROM Professors WHERE username = '******'", username);
            var professor = new ProfessorModel();

            sqlConnection1.Open();

            var reader = GetDatabaseResults(queryString);

            if (reader.HasRows)
            {
                while (reader.Read())
                {
                    var Professor_Name = reader.GetString(0);
                    var Professor_ID = reader.GetInt32(1);
                    var user = reader.GetString(2);
                    var password = reader.GetString(3);
                    professor = new ProfessorModel { Professor_Name = Professor_Name, Professor_ID = Professor_ID, username = user, password = password};
                }
            }

            sqlConnection1.Close();

            return professor;
        }
        public IEnumerable<ProfessorModel> GetAllProfessors()
        {
            List<ProfessorModel> professors = new List<ProfessorModel>();
            sqlConnection1.Open();
            var reader = GetDatabaseResults("SELECT Professor_Name, Professor_ID FROM Professors");

            if (reader.HasRows)
            {
                while (reader.Read())
                {
                    var Professor_Name = reader.GetString(0);
                    var Professor_ID = reader.GetInt32(1);
                    var professor = new ProfessorModel { Professor_Name = Professor_Name, Professor_ID = Professor_ID };
                    professors.Add(professor);
                }
            }

            sqlConnection1.Close();

            return professors;
        }