Problem when inserting data into SQL Compact by ADO.Net Entity Framework

Question

        DatabaseEntities de = new DatabaseEntities();
        Income income = de.Incomes.CreateObject();            
        income.Id = de.Incomes.Max(f => f.Id) + 1;            
        income.Person = Users.SelectedValue.ToString();
        income.Value = value;
        income.Unit = Unit.SelectedValue.ToString();
        income.Description = Desc.Text;
        de.Incomes.AddObject(income);
        de.SaveChanges();           

I have used the code section above to insert an Income object into SQL Compact database after that i have used the following statement to bind data to a DataGridView:

        IncomeGridView.DataSource = de.Incomes;

I saw the new data but after I closed my program I did not see the new data in table. Can anyone explain me?

Answer 1

Possibly this - http://erikej.blogspot.com/2010/05/faq-why-does-my-changes-not-get-saved.html

Answer 2

linh ...may i know which actual path we should try for...the path that our .sdf file copied to debug folder or the path .sdf file originally belongs to?? i have the same problem for few days probably with the code diffrent than urs. when application runs my insert/update works fine, n after closing n re debuging the update values shows too. only problem is that there is no any updates in original table in database. plz sir can u describe me easily bexause im new with mobile application. thank u!