Entity Framework Core 和 Entity Framework 6 都安装了答案

【问题标题】：Both Entity Framework Core and Entity Framework 6 are installedEntity Framework Core 和 Entity Framework 6 都安装了
【发布时间】：2017-08-05 02:28:45
【问题描述】：

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

add-migration "Initial Create"

并得到以下错误：

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.

你知道如何解决这个错误吗？

更新 1 - 2017 年 3 月 14 日 - 运行命令后收到结果

PM> dotnet ef migrations add "Initial Create"

我看到以下输出，最后带有错误消息。

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>

【问题讨论】：

您发布的第一个错误（关于安装了 EF6）不是错误。这只是一个警告。应该从该命令成功添加 EFCore 迁移。除了警告之外还有其他问题吗？
我收到“构建失败”。该警告后的消息。
当 EF Core 执行任何命令时，首先它会构建项目。错误消息表明无法构建项目。尝试在 Visual Studio 中构建项目并查看错误列表窗口以查看构建错误。此故障与EF具体无关。

标签： asp.net-core entity-framework-core

【解决方案1】：

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

【讨论】：

感谢 Agua，我已经用“dotnet ef migrations add Initial”命令的结果更新了我的问题。你知道如何解决这个错误吗？
您是否尝试从类库添加迁移？
不，我从新的 Asp.net Core Web 应用程序添加迁移。
你能发布你的 Startup.cs 吗？
并在您的 csproj 中找到？

【解决方案2】：

也许您的解决方案中至少有两个项目，每个项目都使用任一版本的 EF。通过发出“Manage NuGet packages for solution...”，您可以验证是否是这种情况。然后，也许您需要牺牲使用 EF 6.x 的那个。之后你需要重新启动VS，也许一些缓存会阻止你卸载它时完全删除它。

编辑：.. 或者你可以和他们相处得很好，但是仔细阅读消息并按照它所说的......

【讨论】：

这就是我所需要的。在我的案例中，诀窍是在从解决方案中包含它的几个项目中删除 EF6 后，我没有重新启动 Visual Studio。即使没有更多的项目有 EF6，只有 EFCore，我仍然收到消息。重新启动 Visual Studio 使其消失。
对我来说也一样。重启VS修复它。
@Alexander_Christov 请详细说明您的答案。这个答案不是很清楚。

【解决方案3】：

我如何在 VS 2017 中解决这个问题

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 资源管理器）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，警报就消失了

您没有看到“.vs”文件夹？

【讨论】：

【解决方案4】：

只是……

编辑您的项目（项目 -> 右键 -> 编辑）并删除 EntityFramewok Line

删除一行

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

并且只使用 EntityFramework Core

【讨论】：

【解决方案5】：

如果同时安装了 Entity Framework Core 和 Entity Framework 6，并且您想使用 Entity Framework 6。
在包管理器控制台中使用此命令：

'EntityFramework\Update-Database'.

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

【讨论】：

【解决方案6】：

对于那些使用Entity Framework 6.3 and later to .Net Core 新端口的用户，解决方案很有可能同时包含 EfCore 和 Ef6 工件。

例如我已将较旧的 EF6 存储库从 .Net Framework 迁移到 Core，但想利用开箱即用的 AspNet Identity Core 子系统，它使用 EfCore。

在迁移过程中，我总是会收到如下错误：

Entity Framework Core 和 Entity Framework 6 都已安装。 Entity Framework Core 工具正在运行。对 Entity Framework 6 使用“EntityFramework6\Update-Database”。

或

Entity Framework 6 和 Entity Framework Core 都已安装。 Entity Framework 6 工具正在运行。对 Entity Framework Core 使用“EntityFrameworkCore\Add-Migration”

解决方案很简单 - 在运行迁移命令时，根据警告，始终使用完全限定的命令来限定命令：

EntityFramework6\Add-Migration Foo
EntityFramework6\Update-Database

或

EntityFrameworkCore\Add-Migration Foo
EntityFrameworkCore\Update-Database

请注意，对于 EF6 粉丝来说，在撰写本文时，移植到 Core 的迁移工具还没有完全达到标准，正如 here 所说。

同样，如果您即使在同一个框架版本中也有多个 DbContext（EfCore 与 Ef6 on Core），您需要指定您尝试定位的特定 DbContext 的名称，例如

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

【讨论】：