EntityKey Constructor (String, String, Object)

 

Initializes a new instance of the EntityKey class with an entity set name and specific entity key pair.

Namespace:   System.Data
Assembly:  System.Data.Entity (in System.Data.Entity.dll)

Public Sub New (
	qualifiedEntitySetName As String,
	keyName As String,
	keyValue As Object
)

Parameters

qualifiedEntitySetName
Type: System.String

A String that is the entity set name qualified by the entity container name.

keyName
Type: System.String

A String that is the name of the key.

keyValue
Type: System.Object

An Object that is the key value.

This example is based on the AdventureWorks Sales Model. The example shows you how to create and use an EntityKey.

Using context As New AdventureWorksEntities()
    Try
        ' Create the key that represents the order. 
        Dim orderKey As New EntityKey("AdventureWorksEntities.SalesOrderHeaders", "SalesOrderID", orderId)

        ' Create the stand-in SalesOrderHeader object 
        ' based on the specified SalesOrderID. 
        Dim order As New SalesOrderHeader()
        order.EntityKey = orderKey

        ' Assign the ID to the SalesOrderID property to matche the key. 
        order.SalesOrderID = CInt(orderKey.EntityKeyValues(0).Value)

        ' Attach the stand-in SalesOrderHeader object. 
        context.SalesOrderHeaders.Attach(order)

        ' 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)

        context.SaveChanges()
    Catch generatedExceptionName As InvalidOperationException
        Console.WriteLine("Ensure that the key value matches the value of the object's ID property.")
    Catch generatedExceptionName As UpdateException
        Console.WriteLine("An error has occured. Ensure that an object with the '{0}' key value exists.", orderId)
    End Try
End Using

.NET Framework
Available since 3.5
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