EntityKey Constructor (String, String, Object)

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 EntityKey(
	string qualifiedEntitySetName,
	string keyName,
	object keyValue


Type: System.String

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

Type: System.String

A String that is the name of the key.

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 (AdventureWorksEntities context =
    new AdventureWorksEntities())
        // Create the key that represents the order.
        EntityKey orderKey =
            new EntityKey("AdventureWorksEntities.SalesOrderHeaders",
                "SalesOrderID", orderId);

        // Create the stand-in SalesOrderHeader object
        // based on the specified SalesOrderID.
        SalesOrderHeader order = new SalesOrderHeader();
        order.EntityKey = orderKey;

        // Assign the ID to the SalesOrderID property to matche the key.
        order.SalesOrderID = (int)orderKey.EntityKeyValues[0].Value;

        // Attach the stand-in SalesOrderHeader object.

        // 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));
        SalesOrderDetail detail = new SalesOrderDetail
            SalesOrderID = orderId,
            SalesOrderDetailID = 0,
            OrderQty = 2,
            ProductID = 750,
            SpecialOfferID = 1,
            UnitPrice = (decimal)2171.2942,
            UnitPriceDiscount = 0,
            LineTotal = 0,
            rowguid = Guid.NewGuid(),
            ModifiedDate = DateTime.Now


    catch (InvalidOperationException)
        Console.WriteLine("Ensure that the key value matches the value of the object's ID property.");
    catch (UpdateException)
        Console.WriteLine("An error has occured. Ensure that an object with the '{0}' key value exists.",

.NET Framework
Available since 3.5
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