The property 'name' is part of the object's key information and cannot be modified. Entity Framework

Question

I am trying to update a record and I get this error message after the context.SaveChanges();

The property \'name\' is part of the object\

Answer 1

Same happened to me today. I set new entity's ID with the old record's ID and the error is gone.

//This checks whether there's a record with same specific data.
var kayitVarMi = _db.Sorgu.FirstOrDefault(a => a.Serial == sorgu.Serial);

                if (kayitVarMi != null) // If there's
                {
                    sorgu.Id = kayitVarMi.Id; //This one does the trick
                    _db.Entry(kayitVarMi).CurrentValues.SetValues(sorgu);
                }
                else // If not
                {
                    _db.Sorgu.Add(sorgu);
                }

                // This whole block is in a transaction scope so I just check recordability.
                if (_db.SaveChanges() > 0)
                {
                    _sorguKaydedildiMi = true;
                }