방법: 엔터티 추가, 수정 및 삭제(WCF Data Services)
WCF Data Services 클라이언트 라이브러리를 사용하면 DataServiceContext에서 개체에 동등한 작업을 수행하여 데이터 서비스의 엔터티 데이터를 만들고 업데이트 및 삭제할 수 있습니다. 자세한 내용은 데이터 서비스 업데이트(WCF Data Services)를 참조하십시오.
이 항목의 예제에서는 Northwind 샘플 데이터 서비스 및 자동 생성된 클라이언트 데이터 서비스 클래스를 사용합니다. 이 서비스 및 클라이언트 데이터 클래스는 WCF Data Services 퀵 스타트를 완료하면 만들어집니다.
예
다음 예제에서는 새 개체 인스턴스를 만든 다음 DataServiceContext의 AddObject 메서드를 호출하여 컨텍스트의 항목을 만듭니다. SaveChanges 메서드를 호출하면 HTTP POST 메시지가 데이터 서비스로 전송됩니다.
' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)
' Create the new product.
Dim newProduct = _
Product.CreateProduct(0, "White Tea - loose", False)
' Set property values.
newProduct.QuantityPerUnit = "120gm bags"
newProduct.ReorderLevel = 5
newProduct.UnitPrice = 5.2D
Try
' Add the new product to the Products entity set.
context.AddToProducts(newProduct)
' Send the insert to the data service.
context.SaveChanges()
Console.WriteLine("New product added with ID {0}.", newProduct.ProductID)
Catch ex As DataServiceRequestException
Throw New ApplicationException( _
"An error occurred when saving changes.", ex)
// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);
// Create the new product.
Product newProduct =
Product.CreateProduct(0, "White Tea - loose", false);
// Set property values.
newProduct.QuantityPerUnit = "120gm bags";
newProduct.ReorderLevel = 5;
newProduct.UnitPrice = 5.2M;
try
{
// Add the new product to the Products entity set.
context.AddToProducts(newProduct);
// Send the insert to the data service.
DataServiceResponse response = context.SaveChanges();
// Enumerate the returned responses.
foreach (ChangeOperationResponse change in response)
{
// Get the descriptor for the entity.
EntityDescriptor descriptor = change.Descriptor as EntityDescriptor;
if (descriptor != null)
{
Product addedProduct = descriptor.Entity as Product;
if (addedProduct != null)
{
Console.WriteLine("New product added with ID {0}.",
addedProduct.ProductID);
}
}
}
}
catch (DataServiceRequestException ex)
{
throw new ApplicationException(
"An error occurred when saving changes.", ex);
}
다음 예제에서는 기존 개체를 검색하고 수정한 다음 DataServiceContext의 UpdateObject 메서드를 호출하여 컨텍스트의 항목을 업데이트됨으로 표시합니다. SaveChanges 메서드를 호출하면 HTTP MERGE 메시지가 데이터 서비스로 전송됩니다.
Dim customerId = "ALFKI"
' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)
' Get a customer to modify using the supplied ID.
Dim customerToChange = (From customer In context.Customers _
Where customer.CustomerID = customerId _
Select customer).Single()
' Change some property values.
customerToChange.CompanyName = "Alfreds Futterkiste"
customerToChange.ContactName = "Maria Anders"
customerToChange.ContactTitle = "Sales Representative"
Try
' Mark the customer as updated.
context.UpdateObject(customerToChange)
' Send the update to the data service.
context.SaveChanges()
Catch ex As DataServiceRequestException
Throw New ApplicationException( _
"An error occurred when saving changes.", ex)
End Try
string customerId = "ALFKI";
// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);
// Get a customer to modify using the supplied ID.
var customerToChange = (from customer in context.Customers
where customer.CustomerID == customerId
select customer).Single();
// Change some property values.
customerToChange.CompanyName = "Alfreds Futterkiste";
customerToChange.ContactName = "Maria Anders";
customerToChange.ContactTitle = "Sales Representative";
try
{
// Mark the customer as updated.
context.UpdateObject(customerToChange);
// Send the update to the data service.
context.SaveChanges();
}
catch (DataServiceRequestException ex)
{
throw new ApplicationException(
"An error occurred when saving changes.", ex);
}
다음 예제에서는 DataServiceContext의 DeleteObject 메서드를 호출하여 컨텍스트의 항목을 삭제됨으로 표시합니다. SaveChanges 메서드를 호출하면 HTTP DELETE 메시지가 데이터 서비스로 전송됩니다.
' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)
Try
' Get the product to delete, by product ID.
Dim deletedProduct = (From product In context.Products _
Where product.ProductID = productID _
Select product).Single()
' Mark the product for deletion.
context.DeleteObject(deletedProduct)
' Send the delete to the data service.
context.SaveChanges()
' Handle the error that occurs when the delete operation fails,
' which can happen when there are entities with existing
' relationships to the product being deleted.
Catch ex As DataServiceRequestException
Throw New ApplicationException( _
"An error occurred when saving changes.", ex)
End Try
// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);
try
{
// Get the product to delete, by product ID.
var deletedProduct = (from product in context.Products
where product.ProductID == productID
select product).Single();
// Mark the product for deletion.
context.DeleteObject(deletedProduct);
// Send the delete to the data service.
context.SaveChanges();
}
// Handle the error that occurs when the delete operation fails,
// which can happen when there are entities with existing
// relationships to the product being deleted.
catch (DataServiceRequestException ex)
{
throw new ApplicationException(
"An error occurred when saving changes.", ex);
}
다음 예제에서는 새 개체 인스턴스를 만든 다음 DataServiceContext의 AddRelatedObject 메서드를 호출하여 관련 주문에 대한 링크와 함께 컨텍스트의 항목을 만듭니다. SaveChanges 메서드를 호출하면 HTTP POST 메시지가 데이터 서비스로 전송됩니다.
Dim productId = 25
Dim customerId = "ALFKI"
Dim newItem As Order_Detail = Nothing
' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)
Try
' Get the specific product.
Dim selectedProduct = (From product In context.Products _
Where product.ProductID = productId _
Select product).Single()
' Get the specific customer.
Dim cust = (From customer In context.Customers.Expand("Orders") _
Where customer.CustomerID = customerId _
Select customer).Single()
' Get the first order.
Dim order = cust.Orders.FirstOrDefault()
' Create a new order detail for the specific product.
newItem = Order_Detail.CreateOrder_Detail( _
order.OrderID, selectedProduct.ProductID, 10, 5, 0)
' Add the new item with a link to the related order.
context.AddRelatedObject(order, "Order_Details", newItem)
' Add the new order detail to the collection, and
' set the reference to the product.
order.Order_Details.Add(newItem)
newItem.Order = order
newItem.Product = selectedProduct
' Send the changes to the data service.
Dim response As DataServiceResponse = context.SaveChanges()
' Enumerate the returned responses.
For Each change As ChangeOperationResponse In response
' Get the descriptor for the entity.
Dim descriptor = TryCast(change.Descriptor, EntityDescriptor)
If Not descriptor Is Nothing Then
If TypeOf descriptor.Entity Is Order_Detail Then
Dim addedItem = TryCast(descriptor.Entity, Order_Detail)
If Not addedItem Is Nothing Then
Console.WriteLine("New {0} item added to order {1}.", _
addedItem.Product.ProductName, addedItem.OrderID.ToString())
End If
End If
End If
Next
Catch ex As DataServiceQueryException
Throw New ApplicationException( _
"An error occurred when saving changes.", ex)
' Handle any errors that may occur during insert, such as
' a constraint violation.
Catch ex As DataServiceRequestException
Throw New ApplicationException( _
"An error occurred when saving changes.", ex)
int productId = 25;
string customerId = "ALFKI";
Order_Detail newItem = null;
// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);
try
{
// Get the specific product.
var selectedProduct = (from product in context.Products
where product.ProductID == productId
select product).Single();
// Get the specific customer.
var cust = (from customer in context.Customers.Expand("Orders")
where customer.CustomerID == customerId
select customer).Single();
// Get the first order.
Order order = cust.Orders.FirstOrDefault();
// Create a new order detail for the specific product.
newItem = Order_Detail.CreateOrder_Detail(
order.OrderID, selectedProduct.ProductID, 10, 5, 0);
// Add the new item with a link to the related order.
context.AddRelatedObject(order, "Order_Details", newItem);
// Add the new order detail to the collection, and
// set the reference to the product.
order.Order_Details.Add(newItem);
newItem.Order = order;
newItem.Product = selectedProduct;
// Send the changes to the data service.
DataServiceResponse response = context.SaveChanges();
// Enumerate the returned responses.
foreach (ChangeOperationResponse change in response)
{
// Get the descriptor for the entity.
EntityDescriptor descriptor = change.Descriptor as EntityDescriptor;
if (descriptor != null)
{
if (descriptor.Entity.GetType() == typeof(Order_Detail))
{
Order_Detail addedItem = descriptor.Entity as Order_Detail;
if (addedItem != null)
{
Console.WriteLine("New {0} item added to order {1}.",
addedItem.Product.ProductName, addedItem.OrderID.ToString());
}
}
}
}
}
catch (DataServiceQueryException ex)
{
throw new ApplicationException(
"An error occurred when saving changes.", ex);
}
// Handle any errors that may occur during insert, such as
// a constraint violation.
catch (DataServiceRequestException ex)
{
throw new ApplicationException(
"An error occurred when saving changes.", ex);
}
참고 항목
태스크
방법: DataServiceContext에 기존 엔터티 연결(WCF Data Services)
방법: 엔터티 관계 정의(WCF Data Services)