public async Task <IActionResult> OnPostAsync(int id)
        {
            if (!ModelState.IsValid)
            {
                return(Page());
            }


            try
            {
                Enrollment newRecord = new Enrollment();
                newRecord.CourseId  = id;
                newRecord.StudentId = Enrollment.StudentId;

                _context.Enrollment.Add(newRecord);
                await _context.SaveChangesAsync();

                return(RedirectToPage("/Courses/Index"));
            }
            catch (Exception)
            {
                ViewData["error"] = ERROR_MESSAGE;
                return(Page());
            }
        }
        public async Task <IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return(Page());
            }

            _context.Attach(Course).State = EntityState.Modified;

            try
            {
                await _context.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!CourseExists(Course.Id))
                {
                    return(NotFound());
                }
                else
                {
                    throw;
                }
            }

            return(RedirectToPage("./Index"));
        }
        public async Task <IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return(Page());
            }
            _context.Student.Add(Student);
            await _context.SaveChangesAsync();

            return(RedirectToPage("./Index"));
        }
        public async Task <IActionResult> OnPostAsync(int?id)
        {
            if (id == null)
            {
                return(NotFound());
            }

            Course = await _context.Course.FindAsync(id);

            if (Course != null)
            {
                _context.Course.Remove(Course);
                await _context.SaveChangesAsync();
            }

            return(RedirectToPage("./Index"));
        }