Why It showing error in modifying db in mvc in edit action

Question

I have a confution in my project that when I am modifying the data to db it shows the error that  Store update insert or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=472540 for information on understanding and handling optimistic concurrency exceptions. I am getting the value which I needed in the HttpPost of edit action method the error arise only when saving it to the db controller [HttpPost] [ValidateAntiForgeryToken] public async Task Edit( StudentDetail studentDetail ) { if (ModelState.IsValid) { studentDetail .CashInHand -= studentDetail .CashReceived; studentDetail .Amount += studentDetail .CashReceived; studentDetail .Date = DateTime.Now; studentDetail .cashReceived = null; db.Entry(studentDetail ).State = EntityState.Modified; await db.SaveChangesAsync(); return RedirectToAction(Index); } return View(studentDetail ); } I am getting details in studentDetail. Then Why is that the error showing ???can anyone please help me to find the solution ??

athira k · Answer

I got it correct but can you please tell me why is that happend ?

Ramesh Palanivel · Answer

Hi athira try this code public async Task Edit( StudentDetail studentDetail ) { if (ModelState.IsValid) { StudentDetail _student=db.tablename.where(x=>x.studentId==studentDetail.studentId).singleordefault(); _student.CashInHand -= studentDetail .CashReceived; _student.Amount += studentDetail .CashReceived; _student.Date = DateTime.Now; _student.cashReceived = null; db.SaveChanges(); return RedirectToAction(Index); } return View(studentDetail ); }

athira k · Answer

I have tried that But it will create another row But I dont want to get another row only need is to modify the row

Ramesh Palanivel · Answer

Hi Athira Instead of EntityState.Modified  change EntityState.Added.. It may work!... for Reference  use the below URL. http://stackoverflow.com/questions/1836173/entity-framework-store-update-insert-or-delete-statement-affected-an-unexpec

Why It showing error in modifying db in mvc in edit action

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=472540 for information on understanding and handling optimistic concurrency exceptions."