HOW TO：顯示變更集 (LINQ to SQL)
您可以使用 GetChangeSet 來檢視 DataContext 所追蹤的變更。
範例
下列範例會擷取所在城市是 London 的客戶、將城市變更為 Paris，並將變更送回給資料庫。
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()
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();
這個程式碼的輸出會與下列類似。 請注意，結尾的摘要會顯示進行了八項變更。
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}