本文整理汇总了VB.NET中System.Data.Objects.ObjectContext.DeleteObject方法的典型用法代码示例。如果您正苦于以下问题:VB.NET ObjectContext.DeleteObject方法的具体用法?VB.NET ObjectContext.DeleteObject怎么用?VB.NET ObjectContext.DeleteObject使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类System.Data.Objects.ObjectContext 的用法示例。
在下文中一共展示了ObjectContext.DeleteObject方法的2个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于我们的系统推荐出更棒的VB.NET代码示例。
示例1: EntityKey
Dim deletedProduct As Object
' Define the key of the product to delete.
Dim productKey As New EntityKey("AdventureWorksEntities.Products", "ProductID", productId)
Using context As New AdventureWorksEntities()
' Get the object to delete with the specified key.
If context.TryGetObjectByKey(productKey, deletedProduct) Then
Try
' Delete the object with the specified key
' and save changes to delete the row from the data source.
context.DeleteObject(deletedProduct)
context.SaveChanges()
Catch ex As OptimisticConcurrencyException
Throw New InvalidOperationException(String.Format("The product with an ID of '{0}' could not be deleted." & _
"Make sure that any related objects are already deleted.", _
productKey.EntityKeyValues(0).Value), ex)
End Try
Else
Throw New InvalidOperationException(String.Format("The product with an ID of '{0}' could not be found." & _
"Make sure that Product exists.", productKey.EntityKeyValues(0).Value))
End If
End Using
开发者ID:VB.NET开发者,项目名称:System.Data.Objects,代码行数:23,代码来源:ObjectContext.DeleteObject
示例2: AdventureWorksEntities
' Specify the order to update.
Dim orderId As Integer = 43680
Using context As New AdventureWorksEntities()
Try
Dim order = (From o In context.SalesOrderHeaders
Where o.SalesOrderID = orderId
Select o).First()
' Change the status and ship date of an existing order.
order.Status = 1
order.ShipDate = DateTime.Today
' You do not have to call the Load method to load the details for the order,
' because lazy loading is set to true
' by the constructor of the AdventureWorksEntities object.
' With lazy loading set to true the related objects are loaded when
' you access the navigation property. In this case SalesOrderDetails.
' Delete the first item in the order.
context.DeleteObject(order.SalesOrderDetails.First())
' Create a new SalesOrderDetail object.
' You can use the static CreateObjectName method (the Entity Framework
' adds this method to the generated entity types) instead of the new operator:
' SalesOrderDetail.CreateSalesOrderDetail(1, 0, 2, 750, 1, (decimal)2171.2942, 0, 0,
' Guid.NewGuid(), DateTime.Today))
Dim detail = New SalesOrderDetail With
{
.SalesOrderID = 0,
.SalesOrderDetailID = 0,
.OrderQty = 2,
.ProductID = 750,
.SpecialOfferID = 1,
.UnitPrice = CDec(2171.2942),
.UnitPriceDiscount = 0,
.LineTotal = 0,
.rowguid = Guid.NewGuid(),
.ModifiedDate = DateTime.Now
}
order.SalesOrderDetails.Add(detail)
' Save changes in the object context to the database.
Dim changes As Integer = context.SaveChanges()
Console.WriteLine(changes.ToString() + " changes saved!")
Console.WriteLine("Updated item for order: {0}", order.SalesOrderID.ToString())
For Each item As SalesOrderDetail In order.SalesOrderDetails
Console.WriteLine("Item ID: {0}", item.SalesOrderDetailID.ToString())
Console.WriteLine("Product: {0}", item.ProductID.ToString())
Console.WriteLine("Quantity: {0}", item.OrderQty.ToString())
Next
Catch ex As UpdateException
Console.WriteLine(ex.ToString())
End Try
End Using
开发者ID:VB.NET开发者,项目名称:System.Data.Objects,代码行数:57,代码来源:ObjectContext.DeleteObject
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