EF Core 數據庫第一種方法：Scaffold-DbContext 不被識別為 cmdlet 的名稱

Question

我正在使用 EF Core，並且正在嘗試從數據庫生成模型。 我創建了一個單獨的 ASP.NET Core Web 應用程序，因為從類庫生成它對我不起作用。

我已經多次成功地從數據庫中生成了實體類，但突然停止工作。 這真的很奇怪，因為我這不是第一次，而且我沒有改變任何東西，是什么導致它停止工作？

這是project.json：

  {
  "dependencies": {
    "Microsoft.EntityFrameworkCore.SqlServer": "1.1.0",
    "Microsoft.EntityFrameworkCore.Tools": "1.1.0-preview4-final",
    "Microsoft.AspNetCore.Mvc": "1.1.0",
    "Microsoft.AspNetCore.Routing": "1.1.0",
    "Microsoft.AspNetCore.Server.IISIntegration": "1.1.0",
    "Microsoft.AspNetCore.Server.Kestrel": "1.1.0",
    "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.1.0",
    "Microsoft.Extensions.Configuration.FileExtensions": "1.1.0",
    "Microsoft.Extensions.Configuration.Json": "1.1.0",
    "Microsoft.Extensions.Logging": "1.1.0",
    "Microsoft.Extensions.Logging.Console": "1.1.0",
    "Microsoft.Extensions.Logging.Debug": "1.1.0",
    "Microsoft.Extensions.Options.ConfigurationExtensions": "1.1.0",
    "Microsoft.NETCore.App": {
      "version": "1.1.0",
      "type": "platform"
    },
    "Microsoft.EntityFrameworkCore.SqlServer.Design": "1.1.0"
  },

  "tools": {

    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
  },

  "frameworks": {
    "netcoreapp1.0": {
      "imports": [
        "dotnet5.6",
        "portable-net45+win8"
      ]
    }
  },

  "buildOptions": {
    "emitEntryPoint": true,
    "preserveCompilationContext": true
  },

  "runtimeOptions": {
    "configProperties": {
      "System.GC.Server": true
    }
  }
}

這是命令：

 Scaffold-DbContext "Server= myserver;Database=db;User Id=sa;Password=pass;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir EntityModels 

錯誤：

 Scaffold-DbContext : The term 'Scaffold-DbContext' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the 
name, or if a path was included, verify that the path is correct and try again.
At line:1 char:1
+ Scaffold-DbContext "Server=myserver;Database=db...
+ ~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Scaffold-DbContext:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

我重新啟動了visual studio，問題仍然存在。

Answer 1

dependencies的版本與tools不同：

從dependencies ：

"Microsoft.EntityFrameworkCore.Tools": "1.1.0-preview4-final",

從tools ：

"Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",