Chia sẻ qua

Entity Framework FAQ

  • Bài viết

The EF FAQ has moved (and been updated substantially). 

It can now be found at <www.ef-faq.org/>

Comments

  • Anonymous
    November 07, 2007
    Frequently Asked Questions and Answers about ADO.Net Entity Framework The ADO.Net Entity Framework team

  • Anonymous
    November 07, 2007
    One of the PMs on the team, Asad Khan, sent me a list of questions and answers which he culled from looking

  • Anonymous
    November 09, 2007
    One of the best learning resources I have found since I joined my team at Microsoft is this page Danny

  • Anonymous
    November 09, 2007
    One of the best learning resources I have found since I joined my team at Microsoft is this page Danny

  • Anonymous
    January 04, 2008
    I've not spent near as much time on this as I would like, but this morning, I decided to do a quick update.

  • Anonymous
    January 04, 2008
    I&#39;ve not spent near as much time on this as I would like, but this morning, I decided to do a quick

  • Anonymous
    January 07, 2008
    Whilst digesting some blogs today I came across; Kaxaml - this is looking like a better and better "XAMLPad"...

  • Anonymous
    May 10, 2008
    Daniel, Have been toying with the EF for a while now and this is the most succint and useful article I have seen on some of the more contentious and advanced scenarios - thx. Am a big fan of nhibernate (and the POCO approach), can you recommned any good guidance/examples on implementing a codegen free approach you alude to in section 2.

  • Anonymous
    May 10, 2008
    Mark, I’m glad you found it helpful.  For more information about building classes from scratch, I recommend looking at the following link to part of the MSDN docs: http://msdn.microsoft.com/en-us/library/bb738559.aspx There’s some pretty good explanation there as well as a fair amount of sample code.  If you have additional questions, don’t hesitate to ask.

  • Danny

  • Anonymous
    May 13, 2008
    Daniel, Have been exploring the EF and a friend at Microsoft Brasil pointed me this blog. Nice work! It's a pretty good FAQ. I still got one question: the lastest EF version shipped with de VS 2008 SP1 Beta still doesn't support entity inheritance? (such as Contact <- Person <- Customer for example) as posted in this FAQ at Question 7.2? Thanks! Rodrigo

  • Anonymous
    May 13, 2008
    Entity inheritance is supported and has been from the first CTP of the EF.  What question 7.2 is talking about is the idea of a property of an entity which is not itself an entity (it doesn't have identity, it can't participate in a relationship, etc.) but which does have some structure.  We call those complex types.  Complex types do not support inheritance and won't for v1, but entities do support it.

  • Anonymous
    May 13, 2008
    Just a quick note to point out a few interesting things about the updated version of the EF which shipped

  • Anonymous
    May 14, 2008
    Daniel Simmons vient de publier sur son blog une FAQ de l'Entity Framework mise à jour avec la nouvelle

  • Anonymous
    May 16, 2008
    Olá pessoal, tudo certo? Para quem anda acompanhando a evolução do Entity Framework, componente importante

  • Anonymous
    May 20, 2008
    Danny Simmons , el cual trabaja en el equipo de Entity Framework y al cual tuve la oportunidad de conocer

  • Anonymous
    May 21, 2008
    Daniel Simmons updated EF FAQ .

  • Anonymous
    May 29, 2008
    As I recall in traditional ADO.NET, it was possible to update a portion of a dataset in order to split persistance operations. Here if SaveChange method of ObjectContext has the ability of persisting some portions of modified and disconnected entities it would be great if I extend my created entities to Save themeself. As entities here are in disconnected mode so it might not all other entities receive the reflected changes by database and some exceptions might be thrown. But It is acceptable and I think it would be still great to be able to Save only a desired portion of entities.

  • Anonymous
    May 30, 2008
    The EF does not have the ability to persist part of the changes to a context.  There are several reasons for this:

  1. The EF model includes entities and relationships as largely separate things while in the CLR object model they overlap quite a bit such that an entity has references to other entities which imply relationships.  If you were to save just an entity, for instance, there are some difficult questions about what that means to the relationships--especially once you look at concurrency checks, relationships which can be modeled either as foreign keys inline in a row or out in link tables, etc.
  2. The idea behind the context is a bit different from the dataset.  It's not intended as a big in memory cache so much as something which represents a unit of work.  So if you have multiple changes to entities which you want to persist separately, the general recommendation would be to use separate contexts.
  • Danny

  • Anonymous
    June 05, 2008
    Danny Simmons , del equipo de Entity Framework ha publicado una nueva actualización de su ya interesante

  • Anonymous
    June 05, 2008
    Daniel Simmons updated EF FAQ . What are the changes? (from Daniel &#39;s post ). Updated: 1.2 Where

  • Anonymous
    June 11, 2008
    The Entity Framework enables developers to reason about and write queries in terms of the EDM model rather than the logical schema of tables, joins, foreign keys, and so on. Many enterprise systems have multiple applications/databases with varying degrees

  • Anonymous
    August 01, 2008
    veel handige info over Entity Framework

  • Anonymous
    August 05, 2008
    How to use Stored Procedures that only return simple data types like double, float and so on? Thanks in advance!

  • Anonymous
    August 09, 2008
    Entity Classes &amp; Architecture Patterns Part of the Entity Framework FAQ . 2. Architecture and Patterns

  • Anonymous
    August 09, 2008
    Entity Classes &amp; Architecture Patterns Part of the Entity Framework FAQ . 2. Architecture and Patterns

  • Anonymous
    August 09, 2008
    Part of the Entity Framework FAQ . 6. Query 6.1. How is Span used? What is Span? (aka. How does the EF

  • Anonymous
    August 09, 2008
    Part of the Entity Framework FAQ . 9. Object Services 9.1. What is ObjectContext.Detach() method used

  • Anonymous
    August 09, 2008
    Part of the Entity Framework FAQ . 13. EDM 13.1. Does Entity Framework support Abstract types in EDM

  • Anonymous
    August 09, 2008
    Part of the Entity Framework FAQ . 18. Multi-threading 18.1. What is the recommendation for running a

  • Anonymous
    August 11, 2008
    As always, the FAQ lives at http://blogs.msdn.com/dsimmons/pages/entity-framework-faq.aspx New in this

  • Anonymous
    September 17, 2008
    As promised, the links from my session today on the new data stuff on 3.5 and 3.5 SP1. Thanks for listening.

  • Anonymous
    September 26, 2008
    Presentation: Data and Data Access - State of the Nation Presenter: Eric Nelson http://blogs.msdn.com/ericnel

  • Anonymous
    October 02, 2008
    Presentation: Presenter: Mike Ormond Presentation: Whats new in Data Presenter: Eric Nelson http://blogs.msdn.com/ericnel

  • Anonymous
    October 15, 2008
    I've had a lot of questions lately on how to display data from two separate tables in the database into

  • Anonymous
    October 19, 2008
    VisualStudio2008发布时，微软给我们带来了LinQtoSQL，解决所谓

  • Anonymous
    October 24, 2008
    Session 1 ADO.NEXT – Entity Framework &amp; Data Services Speaker: Eric Nelson http://blogs.msdn.com/ericnel

  • Anonymous
    January 08, 2009
    I made a round of updates to the EF FAQ a while back but then had some trouble with the blog software

  • Anonymous
    January 08, 2009
    Lately everyone in my team and around my bay have been talking about Entity Framework. Well since I have

  • Anonymous
    January 08, 2009
    Lately everyone in my team and around my bay have been talking about Entity Framework. Well since I have

  • Anonymous
    May 27, 2009
    Olá pessoal, tudo certo? Aqui no blog tenho aproveitado para falar bastante sobre os vários cenários

  • Anonymous
    June 15, 2010
    for being the first sticky thread at  social.msdn.microsoft.com/.../threads I miss ongoing information here. Where is the real EF source?

  • Anonymous
    January 05, 2011
    In my project i want to add an table in database that already exists using entity framework.if i want to add an column in table,how can do these pro grammatically not by UI.

  • Anonymous
    January 05, 2011
    @Santhosh, This kind of question is best posted to the EF forum (social.msdn.microsoft.com/.../threads) or to stackoverflow. Good luck, Danny

  • Anonymous
    March 29, 2011
    Is POCO dynamically derived from EntityObject? and can we custom the dynamic derived behavior? (Such as we let it implement some custom interface)

  • Anonymous
    March 29, 2011
    @GoldyWang, No, the POCO objects aren't dynamically derived from EntityObject.  There are two ways for POCO to work:

  1. The POCO objects have no constraints on them--they don't derive from anything in particular and the EF doesn't create any new types that derive from them.
  2. The EF creates dynamic types which inherit from your POCO objects (not the other way around). Unfortunately there's not a mechanism built into the EF for customizing the dynamically created objects.  You might want to consider contacting Jeff Derstadt or Arthur Vickers who might be able to help you more.
  • Danny