Scaffold-DbContext：找不到命令

Question

i try to reverse engnieer my models from an existing database, but the command: Scaffold-DbContext "Server=(db);Database=xxxx;Trusted_connection=true;" Microsoft.EntityFrameWorkCore.SqlServer -OutputDir Models Scaffold-DbContext "Server=(db);Database=xxxx;Trusted_connection=true;" Microsoft.EntityFrameWorkCore.SqlServer -OutputDir Models doesn´t work.

I get the error message like in the title.

I installed the Nuget packeges :

Microsoft.EntityFrameworkCore.SqlServer
Microsoft.EntityFrameworkCore.Tools
Microsoft.EntityFrameworkCore.SqlServer.Design

and i don´t know why it doesn´t work.( dotnet ef commands works) I´m sure its a little problem but i can´t find the solution. Please help me

My .csproj:

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>netcoreapp1.1</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="IdentityServer4">
      <Version>1.5.0</Version>
    </PackageReference>
    <PackageReference Include="IdentityServer4.AccessTokenValidation">
      <Version>1.2.0</Version>
    </PackageReference>
    <PackageReference Include="IdentityServer4.AspNetIdentity">
      <Version>1.0.1</Version>
    </PackageReference>
    <PackageReference Include="Microsoft.AspNetCore" Version="1.1.1" />
    <PackageReference Include="Microsoft.AspNetCore.Identity">
      <Version>1.1.1</Version>
    </PackageReference>
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore">
      <Version>1.1.1</Version>
    </PackageReference>
    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="1.1.2" />
    <PackageReference Include="Microsoft.AspNetCore.StaticFiles" Version="1.1.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore">
      <Version>1.1.1</Version>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer">
      <Version>1.1.2</Version>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design">
      <Version>1.1.2</Version>
    </PackageReference>
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools">
      <Version>1.1.1</Version>
    </PackageReference>
    <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="1.1.1" />
    <PackageReference Include="Microsoft.VisualStudio.Web.BrowserLink" Version="1.1.0" />
  </ItemGroup>
  <ItemGroup>
      <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="1.1.1" PrivateAssets="All" />
    </ItemGroup>
  <ItemGroup>
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="1.0.1" />
  </ItemGroup>
</Project>

Answer 1

Install Microsoft EntityFrameworkCore tools nuget package in your project by running the following command in Package Manager Console.

Install-Package Microsoft.EntityFrameworkCore.Tools -Version 1.1.2

This will install the Cmdlets to run Database first approach via Package Manager Console. For details visit https://www.nuget.org/packages/Microsoft.EntityFrameworkCore.Tools/

Answer 2

This worked for me

use dotnet ef dbcontext scaffold instead of Scaffold-DbContext

for instance

dotnet ef dbcontext scaffold "Host=my_host;Database=my_db;Username=my_user;Password=my_pw" Npgsql.EntityFrameworkCore.PostgreSQL -c ContextName -o OutPutFolder 

run dotnet ef dbcontext scaffold -h to see options u can pass !

Answer 3

Modify the .csproj file to include the following section:

<ItemGroup>
    <DotNetCliToolReference
        Include="Microsoft.EntityFrameworkCore.Tools.DotNet"
        Version="1.0.0-msbuild3-final" />
</ItemGroup>

This step is only necessary if the .csproj file wasn't automatically modified to add the entry when the Tools package was installed. See https://github.com/aspnet/EntityFramework/issues/7358 .

Restore the packages:

dotnet restore

Now, check your dotnet ef dbcontext scaffold command.