public bool Edit(Class editClass)
 {
     string sql = "UPDATE " + TBL_CLASSES + " SET "
         + CLASS_NAME + "='" + editClass.name + "' "
         + "WHERE " + CLASS_ID + "=" + editClass.id + ";";
     return _db.ExecuteInsertUpdateDelete(sql);
 }
 public bool Add(Class newClass)
 {
     string sql = "INSERT INTO " + TBL_CLASSES
         + " (" + CLASS_NAME + ") "
         + "VALUES ('" + newClass.name + "');";
     return _db.ExecuteInsertUpdateDelete(sql);
 }
 public Student(long id, String name, double grade, int height, Class class_id)
 {
     this._id = id;
     this._name = name;
     this._grade = grade;
     this._height = height;
     this._class_id = class_id;
 }
 public bool Delete(Class editClass)
 {
     string sql = "DELETE FROM " + TBL_CLASSES
         + " WHERE " + CLASS_ID + "=" + editClass.id + ";";
     return _db.ExecuteInsertUpdateDelete(sql);
 }
        public List<Student> GetStudentsInClass(Class fromClass)
        {
            List<Student> studentsList = new List<Student>();
            String sql = "SELECT * FROM " + TBL_STUDENTS
                + " WHERE " + CLASS_ID + "=" + fromClass.id + ";";
            DataTableReader records = _db.ExecuteSelect(sql);

            while (records.Read())
            {
                studentsList.Add(new Student(
                    Convert.ToInt32(records[STUD_ID]),
                    (String)records[STUD_NAME],
                    Convert.ToDouble(records[STUD_GRADE]),
                    Convert.ToInt32(records[STUD_HEIGHT]),
                    fromClass
                    ));
            }
            records.Close();

            return studentsList;
        }