LINQ-to-SQL CompiledQuery.Compile()与Update,Delete,Insert？

using (var context = new DataContext())
{
    var customer = (from c in context.Customers
                    where c.CustomerID == customerID
                    select c).Single();

    customer.City = "New City";
    context.SubmitChanges();
}

using (var context = new DataContext())
{
    var customer = (from c in context.Customers
                    where c.CustomerID == customerID
                    select c).Single();

    context.Customers.DeleteOnSubmit(customer);
    context.SubmitChanges();
}

using (var context = new DataContext())
{
    var newCustomer = new Customer
    {
        CustomerID = customerID,
        CompanyName = "New Company",
        City = "New City"
    };

    context.Customers.InsertOnSubmit(newCustomer);
    context.SubmitChanges();
}