Question

look at these two codes

1. First:

   Slide _Slide = DataContext.Slides.SingleOrDefault(rec => rec.Id == _SlideObj.Id);
   _Slide = _SlideObj;            
   DataContext.SaveChanges();
   

2. Second:

   Slide _Slide = DataContext.Slides.SingleOrDefault(rec => rec.Id == _SlideObj.Id);
   _Slide.Title = _SlideObj.Title;
   _Slide.Description = _SlideObj.Description;
   DataContext.SaveChanges();
   

The first code does not update the database but the second updates. Why? How can I change my code to do update operation in first method? (I like to use first method)

Answer 1

There is no update because you didn’t change anything. In the first case, you just changed _Slide to point to a different Slide.