In LINQ to SQL, DataContext object keeps track of all the items that are updated, deleted or inserted into the database.
GetChangeSet() method.using (var db = new CustomerDataContext(@"Data Source=(localdb)\ProjectsV13;Initial Catalog=CustomerDB;"))
{
    var addedCustomer = new Customer()
    {
        FirstName = "Maria",
        LastName = "Anders",
        Address = "Obere Str. 57",
    };
    db.Customers.InsertOnSubmit(addedCustomer);
    var deletedCustomer = db.Customers
        .Where(c => c.CustomerId == 105)
        .FirstOrDefault();
    db.Customers.DeleteOnSubmit(deletedCustomer);
    var updatedCustomer = db.Customers
        .Where(c => c.FirstName == "Elizabeth")
        .FirstOrDefault();
    updatedCustomer.Address = "Obere Str. 59";
    var changeSet = db.GetChangeSet();
    Console.WriteLine("Total changes : {0}", changeSet);
    db.SubmitChanges();
}