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

athira k

9y4.8k.NET

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 ??

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athira k9y ago
I got it correct but can you please tell me why is that happend ?
Ramesh Palanivel9y ago
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 k9y ago
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 Palanivel9y ago
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