public IActionResult EditLesson(CreateLessonView model) { USOSContext context = this.initContext(); Lesson editLesson = context.Lesson.Find(model.lessonID); if (model.lectureID != null) { editLesson.lecture = context.Lecture.Find(Convert.ToInt32(model.lectureID)); } if (model.lecturerID != null) { editLesson.lecturer = _userManager.FindByNameAsync(model.lecturerID).Result; } var select = context.LessonsGroup.Where(x => x.lesson.ID == model.lessonID).Select(x => new LessonsGroup(x)); context.LessonsGroup.RemoveRange(select); if (model.group != null) { foreach (int g in model.group) { Group group = context.Group.Find(g); LessonsGroup newLessonGroup = new LessonsGroup(); newLessonGroup.group = group; newLessonGroup.lesson = editLesson; context.LessonsGroup.Add(newLessonGroup); } } context.Entry(editLesson.lecturer).State = EntityState.Unchanged; context.SaveChanges(); return(RedirectToAction("Lessons", "Admin")); }