Add-Migration fails because EntityFrameworkCore.To

问题:

I want to create a console application with EF Core by following this tutorial: http://ef.readthedocs.io/en/latest/platforms/full-dotnet/new-db.html.

My problem is, I cannot execute the statement

Add-Migration 

as described in the tutorials. It shows me:

PM> Add-Migration MyFirstMigration
Cannot execute this command because 'Microsoft.EntityFrameworkCore.Tools' is not installed in project 'src\AppEf'. Add 'Microsoft.EntityFrameworkCore.Tools' to the 'tools' section in project.json. See http://go.microsoft.com/fwlink/?LinkId=798221 for more details.

All added assemblies:

What is wrong?

Update

The statement dotnet restore works and dotnet-ef --help does not work at all.

And you can see, the statement is execute in project folder.

回答1:

As a few people mentioned in the comments, Microsoft.EntityFrameworkCore.Tools needs to be added to the tools section of project.json.

I've tested this project.json with the latest (July 2016) versions of EF Core and the tooling packages, and it works:

{
    "buildOptions": {
    "emitEntryPoint": true
  },
  "dependencies": {
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.0",
    "Microsoft.EntityFrameworkCore.Design": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    },
    "Microsoft.NETCore.App": {
      "type": "platform",
      "version": "1.0.0"
    }
  },
  "frameworks": {
    "netcoreapp1.0": {}
  },
  "tools": {
    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final"
  },
  "version": "1.0.0-*"
}

To use it, execute these commands from inside the project folder:

λ dotnet restore
log  : Restore completed in 2810ms.

λ dotnet ef --help
Compiling EfCoreTester2 for .NETCoreApp,Version=v1.0                                                                            
Compilation succeeded.                                                                                                          
    0 Warning(s)                                                                                                                
    0 Error(s)                                                                                                                  
Time elapsed 00:00:01.7208394                                                                                                   

Entity Framework .NET Core CLI Commands 1.0.0-preview2-21431
Usage: dotnet ef [options] [command]
Options:
  -h|--help                      Show help information
  -v|--verbose                   Enable verbose output
  --version                      Show version information
(... etc)

At first, I was getting No executable found matching command "dotnet-ef" until I realized that you have to execute the commands from inside the project folder (src\projectName in my case). If you try to do it from the solution root directory, it won't work.

回答2:

I ended up with such package configuration

"dependencies": {
  "Microsoft.NETCore.App": {
    "version": "1.0.1",
    "type": "platform"
  },
  "Microsoft.EntityFrameworkCore.Design": "1.0.1",
  "Microsoft.EntityFrameworkCore.SqlServer.Design": "1.0.1",
  ...
}

"tools": {
  "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview3-final",
  "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview3-final"
},

and this command works

Scaffold-DbContext
    "Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=<DB name>;Integrated Security=True;"
    "Microsoft.EntityFrameworkCore.SqlServer"
    -OutputDir Entities
    -Context "ApplicationDbContext"
    -DataAnnotations
    -Force
    -Project <Project name>.Data
    -StartupProject <Project name>.Api

Here I scaffold a context into a separate class library project with name Data where the web app is Api