How to save derived type (TPT) in Entity Framework?

Posted by Peter Stegnar on Stack Overflow See other posts from Stack Overflow or by Peter Stegnar
Published on 2010-04-22T09:12:15Z Indexed on 2010/04/22 9:13 UTC
Read the original article Hit count: 218

Filed under:

entity-framework

|

inheritance

|

c#

I have problems with saving derived type (TPT) with Entity Framework to database.

Let's say I have base entity Animal and derived type Dog.

I want to save Dog entity.

I thought that I could do it like contex.AddToDogs(), but contex contain only base entity - Animal. So I can only save Animal object - contex.AddToAnimals().

I have also tried with contex.AddObject("Animals", dogInstance), but I get the following error: The member with identity 'NavigationProperty' does not exist in the metadata collection.

But I have add EntityReference to the "NavigationProperty".

So how to save derived type in EF?

© Stack Overflow or respective owner

Related posts about entity-framework

Differences Between NHibernate and Entity Framework

as seen on ASP.net Weblogs - Search for 'ASP.net Weblogs'
Introduction NHibernate and Entity Framework are two of the most popular O/RM frameworks on the .NET world. Although they share some functionality, there are some aspects on which they are quite different. This post will describe this differences and will hopefully help you get started with the one… >>> More
Entity Framework & Binding syncronisation

as seen on Stack Overflow - Search for 'Stack Overflow'
* EDIT * Sorry, I should make it clearer. Imagine I have an entity: public class MyObject { public string Name { get; set; } } And I have a ListBox: <ListBox x:Name="lbParts"> <ListBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding Name}"/> … >>> More
Joins and UI Binding with the Entity Framework

as seen on Internet.com - Search for 'Internet.com'
Learn how to build queries with the Entity Framework that involve multiple tables as well as binding in the UI with the EntityDataSource. >>> More
Frederick .NET User Group April 2010 Meeting

as seen on Geeks with Blogs - Search for 'Geeks with Blogs'
FredNUG is pleased to announce that we have an excellent speaker lined up for April. On April 20th, we’ll start with pizza and social networking at 6:30 PM. Then, starting at 7 PM, Dane Morgridge will present “Getting Started with Entity Framework 4” The scheduled agenda is: 6:30 PM - 7:00… >>> More
[News] NHibernate vs MS Entity Framework

as seen on Dot Net Guru - Search for 'Dot Net Guru'
Voil? une question qui se posera de plus en plus avec la sortie prochaine de .NET V4 et Entity Framework V4, l'outil de mapping objet/relationnel de Microsoft. M?me s'il est vrai que l'opinion de Ayende peut para?tre biais?e du fait qu'il est contributeur NHibernate, son point de vue et surtout ses… >>> More

Related posts about inheritance

Single Table Inheritance (Database Inheritance design options) pros and cons and in which case it us

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I study about today about 2 database design inheritance approaches: 1. Single Table Inheritance 2. Class Table Inheritance In my student opinion Single Table Inheritance make database more smaller vs other approaches because she use only 1 table. But i read that the more favorite approach… >>> More
How to use Private Inheritence aka C++ in C# and Why not it is present in C#

as seen on Stack Overflow - Search for 'Stack Overflow'
I know that private inheritance is supported in C++ and only public inheritance is supported in C#. I also came across an article which says that private inheritance usually defines a HAS-A relationship and kind of an aggregation relationship between the classes. EDIT: C++ code for private inheritance: The… >>> More
[PHP] Singleton class and using inheritance

as seen on Stack Overflow - Search for 'Stack Overflow'
I have am working on a web application that makes use of helper classes. These classes hold functions to various operation such as form handling. Sometimes I need these classes at more than one spot in my application, The way I do it now is to make a new Object. I can't pass the variable, this will… >>> More
Difference between Inheritance and Composition

as seen on Stack Overflow - Search for 'Stack Overflow'
Are Composition and Inheritance are the same? If I want to implement the composition pattern, how can I do that in Java? >>> More
C# Interface Inheritance (Basics)

as seen on Stack Overflow - Search for 'Stack Overflow'
Why does the following produce a compiler error: public interface OwnSession : ISession { } [...] OwnSession s = SessionFactory.OpenSession(); // compiler error (in german unfortunately) [...] "SessionFactory" returns a "ISession" on "OpenSession()" (NHibernate) >>> More