public int Delete(Course course)
        {
            string sql = $"delete from Course where CourseId={course.CourseId}";

            return(SQLHelper.ExecuteNonQuery(sql));
        }
        public int Update(Course course)
        {
            string sql = $"update Course set CourseContent='{course.CourseContent}' where CourseId={course.CourseId}";

            return(SQLHelper.ExecuteNonQuery(sql));
        }