EF 5 Enable-Migrations : No context type was found in the assembly

Question

I have 4 projects :

Toombu.Entities : all models are there
Toombu.DataAccess: Mapping, Repository and ToombuContext
Toombu.Logique : Logic of my application
Toombu.Web : MVC 4 application. With all others DLL.

I tried to enable migration in Toombu.Web but i had this error :

No context type was found in the assembly

How can I enable migration ?

Extrasystole

Answer 1

use -ProjectName option in Package Manager Console:

Enable-Migrations -ProjectName Toombu.DataAccess -StartUpProjectName Toombu.Web -Verbose

Snowshed

Or select the correct project in the 'Default project:' drop-down at the top of the PM Console (in VS2013 - not sure in earlier versions) – Throckmorton

Yes, it's another way :-) – Snowshed

I think there is an error here, -ProjectName Toombu.DataAccess will enable the migrations in this project, not in the Toombu.Web as required. – Iquitos

This should do the trick: Enable-Migrations -ContextAssemblyName Toombu.DataAccess -ProjectName Toombu.Web -Verbose – Iquitos

Checking whether a <b>Context file</b> has been added to the project before everything else is the first step. – Metaplasm

Complementing Rehan, if you run this command without context file, Package Manager Console will fire System.Data.Entity.Migrations.Infrastructure.MigrationsException: No context type was found in the assembly – Side

If you have a signed Assembly it still cannot find the Configuration class. So uncheck 'signing' the assembly and rerun the Enable-Migrations command. After this, you can reset the 'siging' settings. – Ritzy

surprising that having the default project set is not enough. – Dietitian

This answer has helped me to solve the problem. In my case, I have a Xamarin.Forms solution with three projects - Backend (for Azure Database connection), one common library, an iOS project and an Android project. The error messages that I have received were the one in the title of the question plus "The EntityFramework package is not installed on project ...". I have solved it by entering the commands in the following format in the Package Manager Console: Enable-Migrations -ProjectName Backend -Verbose and after that add-migration -ProjectName Backend Initial. – Ulani

Answer 2

I am surprised that no one mentioned the obvious answer to this question: Entity Framework requires a context before enable-migrations will work. The error message the OP posted suggests that no context was found. Sure, it could be because the package manager console doesn't "see" the context--in which case the accepted answer is a possible solution (another solution is one I suggest, below). But a context must exist in the current project (assembly) before any other solutions will work.

What does it mean to have a context? It means that there must exist a class in your project that inherits from DbContext (in System.Data.Entity). Here is an example:

public class MyDbContext : DbContext
{
    public MyDbContext()
    {
    }
}

Be sure you use

using System.Data.Entity;

before the code above has access to the DbContext class and that you have used NuGet to get Entity Framework 4.1 or later for the current project.

If all along you had a context but the Package Manager Console just doesn't "see" it: In Visual Studio 2013 you don't have to use the -ProjectName switch. Instead, go to the Package Manager Console (it's available in the View | Other Windows list), and look at the two dropdowns that appear at the top of the Package Manager Console dockable window. The first dropdown is for Package Source; the second is for Default Project. If you dropdown the Default Project and select a project in your solution then whatever commands you issue in the Package Manager console will be executed against the selected project.

Touraco

Upvoted. I know this is a few months old, but this is EXACTLY the issue I had and the obvious was the problem. In my case, I cut and pasted the code, but forgot (PTF) to install EF package. Never overlook the obvious! – Gavin

This answer reminded me that I refactored the DbContext into another assembly (class library). That directed me to this solution (#18127211), which yielded the command line enable-migrations -ProjectName nameOfMainProject -ContextProjectName nameOfProjectWithDbContext -Verbose – Oren

This answer is the solution even in Entity Framework version 6.1.3 – Puberty

Answer 3

Change the default project and choose the startup project from dropdown:

Dishonest

@sadjad Kahzaie Sadjad, please contact me. – Romy

Answer 4

In my case, the NuGet package "Microsoft.EntityFrameworkCore.Tools" was missing

Adolphus

After this step I just run Add-Migration "firstCommit". This works for me – Honorable

Ohh yes, baby! That was the one. – Laritalariviere

Answer 5

If anyone is still facing this problem. I solved it by using the following command:

Enable-Migrations -ProjectName <YOUR_PROJECT_NAME> -ContextTypeName <YOUR_CONTEXT_NAME>

Don't forget to use the full path to your context name.

Highly

Answer 6

I created a Class in the Models directory called: myData with the following code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;

namespace Vidly.Models
{
    public class MyDbContext : DbContext
    {
        public MyDbContext()
        {
        }
    }
}

rebuilt the app with: control-shift-b

then ran the following in the nuGet Console:

Enable-Migrations -StartUpProjectName Vidly -ContextTypeName Vidly.Models.MyDbContext -Verbose

the Console returned:

Using StartUp project 'Vidly'. Using NuGet project 'Vidly'. Checking if the context targets an existing database... Code First Migrations enabled for project Vidly. Enable-Migrations -StartUpProjectName Vidly -ContextTypeName Vidly.Models.myData -Verbose

And the FrameWork created a Migrations directory and wrote a Configuration.cs template in there with the following code:

namespace Vidly.Migrations
{
    using System;
    using System.Data.Entity;
    using System.Data.Entity.Migrations;
    using System.Linq;

    internal sealed class Configuration : DbMigrationsConfiguration<Vidly.Models.MyDbContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = false;
        }

        protected override void Seed(Vidly.Models.MyDbContext context)
        {
            //  This method will be called after migrating to the latest version.

            //  You can use the DbSet<T>.AddOrUpdate() helper extension method 
            //  to avoid creating duplicate seed data.
        }
    }
}

Iquitos

Answer 7

Follow the below steps to resolve the issue

Install-Package EntityFramework-IncludePrerelease

or Install entity framework from Nuget Package Manager

Restart visual studio

After that I was getting "No context type was found in assembly"

To resolve it - This "No context" that mean you need to create class in "Model" folder in your app with suffix like DbContext ... like this AppDbContext. There you need to include some library using System.Data.Entity;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;


namespace Oceans.Models
{
    public class MyDbContext:DbContext
    {
        public MyDbContext()
        {
        }
    }
}

After that run the below command on Package Manager:

Enable-Migrations -ProjectName <YourProjectName> -ContextTypeName <YourContextName>

My Project Name is - MyFirstApp and AppDbContext is inside the Model Folder so path is like

Enable-Migrations -StartUpProjectName MyFirstApp -ContextTypeName MyFirstApp.Models.AppDbContext

Determinate

Answer 8

In mosh tutorial, individual user account was selected which created a db context in the template. Also, make sure EntityFramework is installed in the Nuget package manager.

Deform

Answer 9

You dbcontext is in Toombu.DataAccess So you should enable migrations in Toombu.DataAccess.

Passable

Answer 10

If you use Both Entity Framework 6 and Entity Framework Core are installed. The Entity Framework 6 tools are running.

Use EntityFrameworkCore\Enable-Migrations for Entity Framework Core. same as for add migration and update database.

Pearce

Answer 11

Thanks for the suggestions, I solved the problem by combining all the solutions here. At first I created the DbContext Model:

 public class MyDbContext: DbContext
    {
        public MyDbContext()
        {
        }
    }

After creating the dbcontext class, I ran the enable-migration command with the project Name: enable-migrations -ProjectName YourProjectName

Heaviside

Answer 12

I had to do a combination of two of the above comments.

Both Setting the Default Project within the Package Manager Console, and also Abhinandan comments of adding the -ContextTypeName variable to my full command. So my command was as follows..

Enable-Migrations -StartUpProjectName RapidDeploy -ContextTypeName RapidDeploy.Models.BloggingContext -Verbose

My Settings::

• ProjectName - RapidDeploy
• BloggingContext (Class Containing DbContext, file is within Models folder of Main Project)

Lir

Answer 13

My problem was link----> problem1

I solved that problem with one simple command line

Install-Package EntityFramework-IncludePrerelease

After that, i needed to face with one more problem, something like:

"No context type was found in assembly"

I solve this really easy. This "No context" that mean you need to create class in "Model" folder in your app with suffix like DbContext ... like this MyDbContext. There you need to include some library using System.Data.Entity;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;


namespace Oceans.Models
{
    public class MyDbContext:DbContext
    {
        public MyDbContext()
        {
        }
    }
}

After that,i just needed this command line:

Enable-Migrations -ProjectName <YourProjectName> -ContextTypeName <YourContextName>

Catherincatherina

Thanks, that worked just fine but with enable-migration command after creating the class. – Birdman

Answer 14

I got this problem first: PM> add-migration first

No migrations configuration type was found in the assembly 'MyProjectName'. (In Visual Studio you can use the Enable-Migrations command from Package Manager Console to add a migrations configuration).

then i tried this:

PM> Enable-Migrations No context type was found in the assembly 'MyProjectName'.

Then the right command for me :

PM> Enable-Migrations -ProjectName MyProjectName -ContextTypeName MyProjectName.Data.Context

After that i got this error message even though Context inherits from DbContext

The type 'Context' does not inherit from DbContext. The DbMigrationsConfiguration.ContextType property must be set to a type that inherits from DbContext.

Then i Installed Microsoft.EntityFrameworkCore.Tools

ITS OK NOW but the message is funny. i already tried add migrations at first :D

Both Entity Framework Core and Entity Framework 6 are installed. The Entity Framework Core tools are running. Use 'EntityFramework6\Enable-Migrations' for Entity Framework 6. Enable-Migrations is obsolete. Use Add-Migration to start using Migrations.

Gee

Answer 15

Change the default project to data access

change the default project dropdown in the package manager console to data access and give enable migrations...

Thats all success

Neat

Answer 16

Using the Package Manager, you need to re-install Entity Framework:

Uninstall-Package EntityFramework -Force

Then install it for each project:

Install-Package EntityFramework

Then do not forget to restart the studio.

Gargoyle

Answer 17

Ensure you are using the same version of Entity Framework across all projects using the NuGet Package Manager.

Recent windows updates may have installed a newer version of Entity Framework into your active project.

Background: Around 16 Mar 2016, I started getting this error when trying to add migrations to a project where I had already enabled migrations and had successfully done migrations for.

I noticed that around March 10, a new stable version of Entity Framework 6 had been released.

If I specified the -ContextTypeName parameter in the enable-migrations command, I got an error indicating the migrations were already enabled.

Resolution:

1) Tools -> Nuget Package Manager -> Manage Nuget Packages for Solution

2) (Not sure if this step is necessary, but..) I updated my version of the Nuget Package Manager to the latest version. Also, after updating my version of Nuget Package Manager, I had to restart Visual Studio twice before the NuGet Command line would work properly.

3) Tools -> Nuget package Manager -> Manage Nuget Packages for Solution -> Search Installed packages -> Type Entity Framework

a. You may see more than one version of Entity Framework there.

b. Click Manage on each version of Entity Framework and ensure that your projects are using the SAME version of Entity Framework.

• Uncheck the version of Entity Framework that you are not using and for the version of Entity Framework you ARE using make sure it is checked across your projects that need it.

Again, as noted in step 2, I had to restart visual studio twice to get the NuGet Package Manager Console to work properly after updating my version of the NuGet Package Manager. I got an error starting the console the first time, and "exception calling createinstancefrom with 8 arguments could not load file or assembly EntityFramework" when running the enable-migrations command the second time.

Restarting visual studio seemed to resolve those issues, however.

Meath

Answer 18

I have been getting this same problem. I have even tried above enable migrations even though I have already done. But it keeps giving same error. Then I had to use the force switch to get overcome this problem. I am sure this will help in someone else's case as well as its a possible work around.

After enabling migration with force, you should update your database (Make sure default project is set correctly). Otherwise you will get another problem like explicit migrations are pending.

Then just execute your add-migrations or any other commands, it should work.

Enable-Migrations -ProjectName <PROJECT_NAME> -ContextTypeName <FULL_CONTEXT_NAMESPACE.YOUR_CONTEXT_NAME> -force

Unrequited

Answer 19

This error getting because of the compiler not getting 'Context' class in your application. So, you can add it manually by Add --> Class and inherit it with 'DbContext' Class For Example :

public class MyDbContext : DbContext
    {
        public DbSet<Customer> Customer { get; set; }
        public MyDbContext()
        {
        }
    }

Preconscious

Answer 20

How to Update table and column in mvc using entity framework code first approach

1: tool > package manager console

2: select current project where context class exist

3: Enable migration using following command PM > enable-migrations

4: Add migration folder name using following command PM > add-migration MyMigrationName

4: Now update database following command PM > update-database

Pelligrini

sorry you are right, i was missing the second step "select current project where context class exist", where there is dbcontext. i was pointing to a wpf project as a start project and selectiong in Package Manger Console EF project as default project . Maybe you should edit your answer to set as a startup project instead of select current project since selection could be in Package Manager console too (select Default Project). – Barbarese

Answer 21

Adding a class which inherits DbContext resolved my problem:

public class MyDbContext : DbContext { public MyDbContext() { } }

Sacramentalist

Answer 22

enable-migrations -EnableAutomaticMigration:$false with this command you can enable migration at Ef 6.3 version because C# enable as default migrations at Ef 6.3 version.

Nosepiece

Answer 23

I have encountered this problem a few times and in my case I uninstalled EntityFramework nuget package and installed EntityFrameworkCore nuget package, entityFramework.design and entityframework.tools

Artiste

Answer 24

I got the same error when I had Authentication disabled/chose "No Authentication'. I re-made my project and chose "Individual User Accounts" and I didn't get the error anymore.

Lecce

Answer 25

When I faced the same problem, I found that I had renamed my project in the solution explorer. I needed to open the project in notepad and change the old name to new name.

Kato

Answer 26

OPs question was for EF5; I had the same problem with EF6, and my experience was quite similar. Multiple answers here reference EntityFrameworkCore, but using that was a huge misdirect for me.

It seems many things can cause the OPs error; I think both jazimov and Sadjad Khazaie presented good solutions that are useful for both EF and EFCore. However, when I had EFCore installed alongside EF6, that actually CAUSED this problem. It seems that my existing EF6 codebase was using EF6 migrations, and with EntityFrameworkCore packages installed, I got the No context type was found in the assembly error because the EFCore add-migration command was running.

When I removed the EntityFrameworkCore packages, the problem went away.

Note: sometimes I got a warning that both EntityFrameworkCore and EntityFramework were installed when I ran add-migration, but not always. One way to be sure: try enable-migrations, which is available with EntityFramework but is not available (or necessary) with EntityFrameworkCore.

Antimasque

Answer 27

Create a class MyDBContext with empty constructor inheriting the DbContext like below

using System.Data.Entity;


namespace VSR.Models
{
    public class MyDbContext: DbContext
    {
        public MyDbContext()
        {

        }
    }
}

Now Try to execute Enable-migrations. It will work.

Pile

Answer 28

Had same error with Micorosoft.EntityFramework and Microsoft.EntityFrameworkCore installed on project. Remove Microsoft.EntityFramework from project and install Microsoft.EntityFrameworkCore.Tools. Then just call update-database

Ferromagnetism

Answer 29

namespace EntityFrameworkCodeFirst.Module
{
    public class MyDbContext: DbContext
    {
        public MyDbContext()
        {
        }
    }
}

And if you have Multiple project in one solution than you have to use below commands:-

Enable-Migrations -ProjectName EntityFrameworkCodeFirst

Sandra

Answer 30

Worked for me:

 UnInstall-Package EntityFramework 

• Restart Visual Studio

Install-Package EntityFramework

• Build project

Sergu

Ridiculous answer. This would not only be a complete waste of time in nearly every case (if trying to solve this OP's question), but also author gives no justification for uninstalling/reinstalling entity framework or any mention of specific versions, etc. – Touraco