The type or namespace name 'DbContext' could not be found [closed]

Question

I had the same issue. Turns out, you need the EntityFramework.dll reference (and not System.Data.Entity).

I just pulled it from the MvcMusicStore application which you can download from: http://mvcmusicstore.codeplex.com/

It's also a useful example of how to use entity framework code-first with MVC.

You need to reference the System.Data.Entity assembly in your project, or install the EntityFramework NuGet package, which will setup everything for you.

Just a quick note. It is DbContext, not DBContext. i.e. with a lowercase 'B'. I discovered this because I had the same problem while intelesense was not working until I tried typing the full name space System.Data.Entity... and name and finally it suggested the lowercase 'b' option:-

System.Data.Entity.DbContext

I had the same problem using VS2010. I know this isn't really an answer. I just thought it might help someone. I resolved it by using the fully qualified name for DBContext.

Instead of

public class MachineDbContext : DbContext

I used

public class MachineDbContext : System.Data.Entity.DbContext

and rebuilt the project. Suddenly VS was happy, and I was even able to remove the fully qualified name, and just use DBContext.

I had the same issue... Installing the EF from Package Manager Console worked for me

the command was: Install-Package EntityFramework

If your compiler doesn't recognize

• System.Data.Entity.Infrastructure
• DbContext
• DbSet
• et alii,

make sure

1. you have Entity Framework 4.1 installed on your machine;

2. in your .csproj file, you have the following reference

   <Reference Include="EntityFramework, Version=4.1.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089, processorArchitecture=MSIL" />
   

   within the element

   <ItemGroup>
     ...
   </ItemGroup>
   

   that houses references to other assemblies.

I had the same problem..I have VS2010 express..

(Note: If you see this problem try checking references to EntityFramework.dll .. May be it is missing.)

The following resolved it for me.

I installed latest MVC 3 Tools Update
then I installed EntityFramework 4.1
or using NUGet ie. from with Visual Studio 2010 Express (Tools->Library Package Manager -> Add library Package reference -> Select Online -> EntityFramework)

Strangely that didnt work..So i had to manually add a reference to "EntityFramework.dll"
try doing a search for the dll ..may be here
"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETFramework\v4.0\"

If you already have it..just add a '.net' reference.

Note: If you use NuGet ,it creates a folder "packages" along side your Solution directory. You will find the "EntityFramework.4.1.10331.0" folder inside it.Within "Libs" folder you will find "EntityFramework.dll" .
Add reference to it using Browse tab and select the above dll.