Entity Framework: “Store update, insert, or delete statement affected an unexpected number of rows (0).” [closed]

Answer 1

I got this same error because part of the PK was a datetime column, and the record being inserted used DateTime.Now as the value for that column. Entity framework would insert the value with millisecond precision, and then look for the value it just inserted also with millisecond precision. However SqlServer had rounded the value to second precision, and thus entity framework was unable to find the millisecond precision value.

The solution was to truncate the milliseconds from DateTime.Now before inserting.

Answer 2

Just make sure table and form both have primary key and edmx updated.

i found that any errors during update were usually because of: - No primary key in Table - No primary key in Edit view/form (e.g. @Html.HiddenFor(m=>m.Id)

Answer 3

    public void Save(object entity)
    {
        using (var transaction = Connection.BeginTransaction())
        {
        try
                {
                    SaveChanges();
                    transaction.Commit();
                }
                catch (OptimisticConcurrencyException)
                {
                    if (ObjectStateManager.GetObjectStateEntry(entity).State == EntityState.Deleted || ObjectStateManager.GetObjectStateEntry(entity).State == EntityState.Modified)
                        this.Refresh(RefreshMode.StoreWins, entity);
                    else if (ObjectStateManager.GetObjectStateEntry(entity).State == EntityState.Added)
                        Detach(entity);
                    AcceptAllChanges(); 
                    transaction.Commit();
                }
        }
    }

Answer 4

  @Html.HiddenFor(model => model.RowVersion)

My rowversion was null, so had to add this to the view which solved my issue

Answer 5

This will also happen if you are trying to insert into a unique constraint situation, ie if you can only have one type of address per employer and you try to insert a second of that same type with the same employer, you will get the same problem.

OR

This could also happen if all of the object properties that were assigned to, they were assigned with the same values as they had before.

        using(var db = new MyContext())
        {
            var address = db.Addresses.FirstOrDefault(x => x.Id == Id);

            address.StreetAddress = StreetAddress; // if you are assigning   
            address.City = City;                   // all of the same values
            address.State = State;                 // as they are
            address.ZipCode = ZipCode;             // in the database    

            db.SaveChanges();           // Then this will throw that exception
        }

Answer 6

I ran into this and it was caused by the entity's ID (key) field not being set. Thus when the context went to save the data, it could not find an ID = 0. Be sure to place a break point in your update statement and verify that the entity's ID has been set.

From Paul Bellora's comment

I had this exact issue, caused by forgetting to include the hidden ID input in the .cshtml edit page