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Cara: Menampilkan ChangeSet

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Anda bisa melihat perubahan yang dilacak dengan DataContext menggunakan GetChangeSet.

Contoh

Contoh berikut ini mengambil pelanggan yang kotanya adalah London, mengubah kota ke Paris, dan mengirimkan perubahan kembali ke database.

Northwnd db = new Northwnd(@"c:\northwnd.mdf");

var custQuery =
    from cust in db.Customers
    where cust.City == "London"
    select cust;

foreach (Customer custObj in custQuery)
{
    Console.WriteLine("CustomerID: {0}", custObj.CustomerID);
    Console.WriteLine("\tOriginal value: {0}", custObj.City);
    custObj.City = "Paris";
    Console.WriteLine("\tUpdated value: {0}", custObj.City);
}

ChangeSet cs = db.GetChangeSet();
Console.Write("Total changes: {0}", cs);
// Freeze the console window.
Console.ReadLine();

db.SubmitChanges();

Dim db As New Northwnd("c:\northwnd.mdf")

Dim custQuery = _
    From cust In db.Customers _
    Where (cust.City = "London") _
    Select cust

For Each custObj As Customer In custQuery
    Console.WriteLine("CustomerID: {0}", custObj.CustomerID)
    Console.WriteLine(vbTab & "Original value: {0}", custObj.City)
    custObj.City = "Paris"
    Console.WriteLine(vbTab & "Updated value: {0}", custObj.City)
Next

Dim cs As ChangeSet = db.GetChangeSet()
Console.Write("Total changes: {0}", cs)
' Freeze the console window.
Console.ReadLine()

db.SubmitChanges()

Output dari kode ini tampak mirip dengan yang berikut ini. Perhatikan bahwa ringkasan di akhir menunjukkan bahwa terdapat delapan perubahan.

CustomerID: AROUT
  Original value: London
  Updated value: Paris
CustomerID: BSBEV
  Original value: London
  Updated value: Paris
CustomerID: CONSH
  Original value: London
  Updated value: Paris
CustomerID: EASTC
  Original value: London
  Updated value: Paris
CustomerID: NORTS
   Original value: London
   Updated value: Paris
CustomerID: PARIS
   Original value: London
   Updated value: Paris
CustomerID: SEVES
   Original value: London
   Updated value: Paris
CustomerID: SPECD
   Original value: London
   Updated value: Paris
Total changes: {Added: 0, Removed: 0, Modified: 8}

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