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EntityKey Constructors

  • Reference

Definition

Namespace:
System.Data
Assembly:
System.Data.Entity.dll

Initializes a new instance of the EntityKey class.

Overloads

EntityKey()

Initializes a new instance of the EntityKey class.
EntityKey(String, IEnumerable<KeyValuePair<String,Object>>)

Initializes a new instance of the EntityKey class with an entity set name and a generic KeyValuePair collection.
EntityKey(String, IEnumerable<EntityKeyMember>)

Initializes a new instance of the EntityKey class with an entity set name and an IEnumerable<T> collection of EntityKeyMember objects.
EntityKey(String, String, Object)

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

EntityKey()

Initializes a new instance of the EntityKey class.

public:
 EntityKey();
public EntityKey ();
Public Sub New ()

Applies to

EntityKey(String, IEnumerable<KeyValuePair<String,Object>>)

Initializes a new instance of the EntityKey class with an entity set name and a generic KeyValuePair collection.

public:
 EntityKey(System::String ^ qualifiedEntitySetName, System::Collections::Generic::IEnumerable<System::Collections::Generic::KeyValuePair<System::String ^, System::Object ^>> ^ entityKeyValues);
public EntityKey (string qualifiedEntitySetName, System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<string,object>> entityKeyValues);
new System.Data.EntityKey : string * seq<System.Collections.Generic.KeyValuePair<string, obj>> -> System.Data.EntityKey
Public Sub New (qualifiedEntitySetName As String, entityKeyValues As IEnumerable(Of KeyValuePair(Of String, Object)))

Parameters

qualifiedEntitySetName
String

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

entityKeyValues
IEnumerable<KeyValuePair<String,Object>>

A generic KeyValuePair collection.

Each key/value pair has a property name as the key and the value of that property as the value. There should be one pair for each property that is part of the EntityKey. The order of the key/value pairs is not important, but each key property should be included. The property names are simple names that are not qualified with an entity type name or the schema name.

Examples

This example shows you how to create and use an EntityKey.

using (AdventureWorksEntities context =
    new AdventureWorksEntities())
{
    try
    {
        // 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.
        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));
        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
        };

        order.SalesOrderDetails.Add(detail);

        context.SaveChanges();
    }
    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 occurred. Ensure that an object with the '{0}' key value exists.",
        orderId);
    }
}

Applies to

EntityKey(String, IEnumerable<EntityKeyMember>)

Initializes a new instance of the EntityKey class with an entity set name and an IEnumerable<T> collection of EntityKeyMember objects.

public:
 EntityKey(System::String ^ qualifiedEntitySetName, System::Collections::Generic::IEnumerable<System::Data::EntityKeyMember ^> ^ entityKeyValues);
public EntityKey (string qualifiedEntitySetName, System.Collections.Generic.IEnumerable<System.Data.EntityKeyMember> entityKeyValues);
new System.Data.EntityKey : string * seq<System.Data.EntityKeyMember> -> System.Data.EntityKey
Public Sub New (qualifiedEntitySetName As String, entityKeyValues As IEnumerable(Of EntityKeyMember))

Parameters

qualifiedEntitySetName
String

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

entityKeyValues
IEnumerable<EntityKeyMember>

An IEnumerable<T> collection of EntityKeyMember objects with which to initialize the key.

Applies to

EntityKey(String, String, Object)

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

public:
 EntityKey(System::String ^ qualifiedEntitySetName, System::String ^ keyName, System::Object ^ keyValue);
public EntityKey (string qualifiedEntitySetName, string keyName, object keyValue);
new System.Data.EntityKey : string * string * obj -> System.Data.EntityKey
Public Sub New (qualifiedEntitySetName As String, keyName As String, keyValue As Object)

Parameters

qualifiedEntitySetName
String

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

keyName
String

A String that is the name of the key.

keyValue
Object

An Object that is the key value.

Examples

This example shows you how to create and use an EntityKey.

using (AdventureWorksEntities context =
    new AdventureWorksEntities())
{
    try
    {
        // 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.
        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));
        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
        };

        order.SalesOrderDetails.Add(detail);

        context.SaveChanges();
    }
    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 occurred. Ensure that an object with the '{0}' key value exists.",
        orderId);
    }
}

Applies to