Why to use DbContext and not ObjectContext

17
votes

I am using EF 4.1 & using DB first approach. I have created my .edmx file too. Now i wish to create my POCO classes.

For this, I have installed EF 4.x DbContext Generator as well as EF 4.x POCO Entity Generator from NuGet.

I am fully aware that it is recommnded to use DbContext for EF 4.1+ as it is derived from ObjectContext. However, i still generated my POCO classes by 1st using EF 4.x POCO Entity Generator & then also by EF 4.x DbContext Generator.

EDIT: Found this ADO.NET DbContext Generator vs. ADO.NET Poco Entity Generator (ObjectContext)

In either of the case, it generates .Context.tt & Model.tt files. So what is the exact difference in files generated by either of the tools ? Why is it recommnded to use DbContext for EF 4.1+ ?

I would also like to know limitations of ObjectContext.

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entity-frameworkentity-framework-4

1 Answers

17
votes

DbContext is newer API which should polish developers experience when using most common tasks - simply the API is better designed but you still have to get ObjectContext from DbContext and use the older API if you want to use some more complex features. If you plan to upgrade EF to 5.x or 6.x in the future it will probably be easier with DbContext because that is what ADO.NET team is recommending.

In terms of generators EF 4.x POCO generator creates more complex classes which internally use relations fix up. This feature proved itself to be quite inefficient when used together with lazy loading so newer EF DbContext generator doesn't use it.

Side note: The code transition from one API to another is fully supported:

  • You can use DbContext constructor accepting ObjectContext to move from ObjectContext API to DbContext API
  • You can use IObjectContext adapter to move from DbContext API to ObjectContext API