Question

我使用Visual Studio 2017并创建一个新的ASP.NET Core项目。我为Entity Framework Core添加迁移，如下所示

add-migration "Initial Create"

并收到以下错误：

Both Entity Framework Core and Entity Framework 6 are installed. The Entity Framework Core tools are running. Use 'EntityFramework\Add-Migration' for Entity Framework 6.
Build Failed.

您知道如何解决此错误吗？

更新1 - 2017年3月14日 - 运行命令后收到的结果

PM> dotnet ef migrations add "Initial Create"

我看到以下输出，并在最后显示错误消息。

Welcome to .NET Core!
---------------------
Learn more about .NET Core @ https://aka.ms/dotnet-docs. Use dotnet --help to see available commands or go to https://aka.ms/dotnet-cli-docs.

Telemetry
--------------
The .NET Core tools collect usage data in order to improve your experience. The data is anonymous and does not include command-line arguments. The
 data is collected by Microsoft and shared with the community.
You can opt out of telemetry by setting a DOTNET_CLI_TELEMETRY_OPTOUT environment variable to 1 using your favorite shell.
You can read more about .NET Core tools telemetry @ https://aka.ms/dotnet-cli-telemetry.

Configuring...
-------------------
A command is running to initially populate your local package cache, to improve restore speed and enable offline access. This command will take up
 to a minute to complete and will only happen once.
Decompressing 0%Decompressing 1%Decompressing 2%Decompressing 3%Decompressing 4%
Decompressing 5%Decompressing 6%Decompressing 7%Decompressing 8%Deco
mpressing 9%Decompressing 10%Decompressing 11%Decompressing 12%Decompressing 13
%Decompressing 14%Decompressing 15%Decompressing 16%Decompressing 17%
Decompressing 18%Decompressing 19%Decompressing 20%Decompressing 21%De
compressing 22%Decompressing 23%Decompressing 24%Decompressing 25%Decompressin
g 26%Decompressing 27%Decompressing 28%Decompressing 29%Decompressing 30%
Decompressing 31%Decompressing 32%Decompressing 33%Decompressing 34%
Decompressing 35%Decompressing 36%Decompressing 37%Decompressing 38%Decompre
ssing 39%Decompressing 40%Decompressing 41%Decompressing 42%Decompressing 43%
Decompressing 44%Decompressing 45%Decompressing 46%Decompressing 47%
Decompressing 48%Decompressing 49%Decompressing 50%Decompressing 51%Deco
mpressing 52%Decompressing 53%Decompressing 54%Decompressing 55%Decompressing 
56%Decompressing 57%Decompressing 58%Decompressing 59%Decompressing 60%
Decompressing 61%Decompressing 62%Decompressing 63%Decompressing 64%
Decompressing 65%Decompressing 66%Decompressing 67%Decompressing 68%Decompress
ing 69%Decompressing 70%Decompressing 71%Decompressing 72%Decompressing 73%
Decompressing 74%Decompressing 75%Decompressing 76%Decompressing 77%
Decompressing 78%Decompressing 79%Decompressing 80%Decompressing 81%Decomp
ressing 82%Decompressing 83%Decompressing 84%Decompressing 85%Decompressing 86
%Decompressing 87%Decompressing 88%Decompressing 89%Decompressing 90%
Decompressing 91%Decompressing 92%Decompressing 93%Decompressing 94%De
compressing 95%Decompressing 96%Decompressing 97%Decompressing 98%Decompressin
g 99%Decompressing 100% 5083 ms
Expanding 0%Expanding 1%Expanding 2%Expanding 3%Expanding 4%Expanding 5%Ex
panding 6%Expanding 7%Expanding 8%Expanding 9%Expanding 10%Expanding 11%
Expanding 12%Expanding 13%Expanding 14%Expanding 15%Expanding 16%Expanding 17%
Expanding 18%Expanding 19%Expanding 20%Expanding 21%Expanding 22%Expand
ing 23%Expanding 24%Expanding 25%Expanding 26%Expanding 27%Expanding 28%
Expanding 29%Expanding 30%Expanding 31%Expanding 32%Expanding 33%Expanding 34
%Expanding 35%Expanding 36%Expanding 37%Expanding 38%Expanding 39%Ex
panding 40%Expanding 41%Expanding 42%Expanding 43%Expanding 44%Expanding 45%
Expanding 46%Expanding 47%Expanding 48%Expanding 49%Expanding 50%Expandin
g 51%Expanding 52%Expanding 53%Expanding 54%Expanding 55%Expanding 56%
Expanding 57%Expanding 58%Expanding 59%Expanding 60%Expanding 61%Expanding 62%
Expanding 63%Expanding 64%Expanding 65%Expanding 66%Expanding 67%Expa
nding 68%Expanding 69%Expanding 70%Expanding 71%Expanding 72%Expanding 73%
Expanding 74%Expanding 75%Expanding 76%Expanding 77%Expanding 78%Expanding 
79%Expanding 80%Expanding 81%Expanding 82%Expanding 83%Expanding 84%
Expanding 85%Expanding 86%Expanding 87%Expanding 88%Expanding 89%Expanding 90%
Expanding 91%Expanding 92%Expanding 93%Expanding 94%Expanding 95%Expand
ing 96%Expanding 97%Expanding 98%Expanding 99%Expanding 100% 13884 ms


dotnet : No executable found matching command "dotnet-ef"
At line:1 char:1
+ dotnet ef migrations add "Initial Create"
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (No executable f...and "dotnet-ef":String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

更新2 - 2017年3月14日 - Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Configuration;
using OdeToFood.Services;
using OdeToFood.Entities;
using Microsoft.AspNetCore.Routing;
using Microsoft.AspNetCore.StaticFiles;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;

namespace OdeToFood
{
    public class Startup
    {
        public IConfiguration Configuration { get; set; }

        public Startup(IHostingEnvironment env)
        {
            // TN - Read setting files
            var builder = new ConfigurationBuilder()
                            .SetBasePath(env.ContentRootPath)
                            .AddJsonFile("appsettings.json")
                            .AddEnvironmentVariables();

            Configuration = builder.Build();
        }

        // This method gets called by the runtime. Use this method to add services to the container.
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();
            services.AddSingleton(Configuration);
            services.AddSingleton<IGreeter, Greeter>();
            services.AddScoped<IRestaurantData, SqlRestaurantData>(); // TN - One instance of this service for each HTTP request.
            services.AddDbContext<OdeToFoodDbContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
            services.AddIdentity<User, IdentityRole>()
                .AddEntityFrameworkStores<OdeToFoodDbContext>();
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole();

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                //app.UseExceptionHandler("/error");
                //app.UseExceptionHandler(new ExceptionHandlerOptions { ExceptionHandlingPath="/error" });

                app.UseExceptionHandler(new ExceptionHandlerOptions
                {
                    ExceptionHandler = context => context.Response.WriteAsync("Opps!")
                });
            }

            //app.UseDefaultFiles();// TN - will pick index.html
            //app.UseStaticFiles();

            app.UseFileServer(); // TN - This will include UseDefaultFiles() and UseStaticFiles

            /*
            app.UseWelcomePage(new WelcomePageOptions
            {
                Path = "/welcome"
            });

            app.Run(async (context) =>
            {
                // TN - Read directly from configuration file
                //var message = Configuration["Greeting"];

                // TN - Dependency Injection - Read from configuration string via IOC
                var message = greeter.GetGreeting();
                await context.Response.WriteAsync(message);
            });
            */


            app.UseIdentity();

            //app.UseMvcWithDefaultRoute();
            app.UseMvc(ConfigureRoutes);

            // TN - if no route matches
            app.Run(ctx => ctx.Response.WriteAsync("Not found."));
        }

        private void ConfigureRoutes(IRouteBuilder routeBuilder)
        {
            //Home/Index
            routeBuilder.MapRoute("Default",
                "{controller=Home}/{action=Index}/{id?}");
        }
    }
}

更新3 - 2017年3月14日 - 添加了csproj文件

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup Label="Globals">
    <SccProjectName>SAK</SccProjectName>
    <SccProvider>SAK</SccProvider>
    <SccAuxPath>SAK</SccAuxPath>
    <SccLocalPath>SAK</SccLocalPath>
  </PropertyGroup>

  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
    <PackageTargetFallback>portable-net45+win8</PackageTargetFallback>
  </PropertyGroup>

  <ItemGroup>
    <!--<Content Include="wwwroot\index.html" />-->
    <DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.0" />
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="1.0.0" />
  </ItemGroup>
  <ItemGroup>
    <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.0.0" />
    <PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="1.1.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" />
    <PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="1.1.0" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="1.1.0" />
  </ItemGroup>
  <ItemGroup>
    <Folder Include="Controllers\" />
    <Folder Include="Data\" />
    <Folder Include="Views\Home\" />
    <Folder Include="wwwroot\images\" />
  </ItemGroup>

</Project>

Answer 1

也许您的解决方案中至少有两个项目，每个项目使用任一版本的EF。通过发出“管理NuGet包以获得解决方案...... ”，您可以验证是否是这种情况。然后，也许你需要使用EF 6.x牺牲那个。之后你需要重新启动VS，也许一些缓存会阻止你在卸载它时完全删除它。

编辑：..或者您可以和他们俩一起生活得很好，但仔细阅读信息并按照说法进行操作......

Answer 2

要为EF7添加迁移，请使用dotnet命令：dotnet ef migrations add Initial
要更新数据库，请使用dotnet命令：dotnet ef database update

Answer 3

我如何在VS 2017中解决此问题

从解决方案中的所有项目中删除EntityFramework（不是EntityFrameworkCore）引用
- 在资源管理器（Windows Explorer）中打开解决方案文件夹
- 关闭VS
- 删除文件夹
- 再次打开解决方案
- 运行update-database，警报消失

您看不到“ .vs”文件夹吗？

Answer 4

如果同时安装了Entity Framework Core和Entity Framework 6，并且您想使用Entity Framework6。
在Package Manager控制台中使用以下命令：

'EntityFramework\Update-Database'.

无需删除或更改任何内容。只需在EF6命令之前添加** EntityFramework **。

Answer 5

就...

编辑您的项目（项目->右键->编辑）并删除EntityFramewok行

删除

之类的行

    <PackageReference Include="Entityframework" Version="6.2.0" />

并且仅使用EntityFramework Core

Answer 6

对于使用新端口Entity Framework 6.3 and later to .Net Core的用户，解决方案很可能同时包含EfCore和Ef6工件。

例如我已经将一个较旧的EF6存储库从.Net Framework迁移到了Core，但是想利用现成的AspNet Identity Core子系统，该子系统使用了EfCore。

在迁移期间，我总是会收到如下错误：

同时安装了Entity Framework Core和Entity Framework 6。实体框架核心工具正在运行。对实体框架6使用“ EntityFramework6 \ Update-Database”。

或

同时安装了Entity Framework 6和Entity Framework Core。实体框架6工具正在运行。为实体框架核心使用“ EntityFrameworkCore \ Add-Migration”

解决方案很简单-根据警告运行迁移命令时，请始终使用完全限定的条件来限定命令：

EntityFramework6\Add-Migration Foo
EntityFramework6\Update-Database

或

EntityFrameworkCore\Add-Migration Foo
EntityFrameworkCore\Update-Database

请注意，对于EF6爱好者，在撰写本文时，根据here，尚未完全迁移到Core的迁移工具。

类似地，如果即使在同一框架版本（EfCore与Ef6，Core）上也有多个DbContext，则需要指定要定位的特定DbContext的名称，例如

EntityFramework6\Add-Migration Foo -Context BarDbContext
EntityFramework6\Add-Migration Baz -Context FooDbContext

实体框架核心和实体框架6都已安装

更新1 - 2017年3月14日 - 运行命令后收到的结果

更新2 - 2017年3月14日 - Startup.cs

6 个答案: