With EF 4.1 on the way and CTP5 being available for few months now I've decided to try out the new functionality. As I see, there are multiple generation items available (DbContext
and three different ObjectContext's
). I also noticed they are not interchangable - I was first using the POCO ObjectContext in one of my app and today switched to DbContext and my entire repository broke. It was based on LoadProperty()
methods, DeleteObject()
and AddObject()
methods and those are all missing on DbSet
class which is used in DbContext
generation.
I know there's a great blog series here http://blogs.msdn.com/b/adonet/archive/2011/01/27/using-dbcontext-in-ef-feature-ctp5-part-1-introduction-and-model.aspx introducing the new functionality but it never really says when to choose what.
My requirements are:
- ASP.NET MVC application, so lazy
loading mostly won't work coz at page
render it will say that context has
already been disposed (that's why I
need easy support for explicit
loading - in EF4 I did it via
Include()
, using POCO context I did it throughLoadProperty()
and now inDbContext
I believe I will use the strongly typedInclude()
). - We probably won't be needing code-first features开发者_如何学运维 (but you never know).
Difference between those two is mostly in API and feature set. DbContext
of course have Include
for query and Load
but you will find it elsewhere. Moreover when using CTP5 assembly you will have strongy typed Include
for both ObjectSet
and DbSet
(available on IQueryable interface as extension method).
Explicit loading (equivalent to LoadProperty
) is performed by Load
method on DbReferenceEntry<T>
or DbCollectionEntry<T>
- check Explicit loading related entities. It works even better then LoadProperty
because you can define filter for loading.
You are starting with the wrong assumption that you can't use lazy load with MVC.
If you manage the context at a higher level, you'll be able to do that without problems.
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