The term 'scaffold-dbcontext' is not recognized as the name of a cmdlet, function, script file, or operable program

Question

When trying to scaffold with asp.net core this command

scaffold-dbcontext "Data Source=(local);Initial
Catalog=MyDb;Integrated Security=True;"
Microsoft.EntityFrameworkCore.sqlserver -outputdir Models

Gives this error.

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 "Data Source=(local);Initial Catalog=MyDB;In ...
+ ~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (scaffold-dbcontext:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

I have tried the solution here, but it does not work for me.

Any idea what the cause/cure could be?

Answer 1

For me apparently it worked once I have also ran in Package Manager console :

 Install-Package Microsoft.EntityFrameworkCore.Tools 

Also make sure :

• To have other dependencies (for example Microsoft.EntityFrameworkCore, Microsoft.EntityFrameworkCore.SqlServer, Microsoft.EntityFrameworkCore.SqlServer.Design...) referenced depending of your needs.

• To select the right assembly as target for your commands in the top-right corner of the PM console (I am frequently fooled by forgetting it...)

Another problem I encountered : with the dbcontext located in a separate class library, I was encountering the following error :

Unable to find provider assembly with name Microsoft.EntityFrameworkCore.SqlServer. Ensure the specified name is correct and is referenced by the project.

Which I was able to fix by setting my class library as Startup project in VS (don't ask why as it seems meaningless, but it worked).

Late edit, there's something else to know : You can't run Scaffold-DbContext against a class library targetting only .Net Standard, you must also enable netcoreapp in it, or Scaffold-DbContext will complain. To support both targets, edit the csproj to put : <TargetFrameworks>netcoreapp2.2;netstandard2.0</TargetFrameworks> Instead of <TargetFramework> section.

After all these you'll be able to run your Scaffold-DbContext command line with proper arguments and connection string.

Answer 2

Had the same problem. In my case i was missing some dependencies, so make sure that you have the following one :

• Microsoft.EntityFrameworkCore
• Microsoft.EntityFrameworkCore.SqlServer
• Microsoft.EntityFrameworkCore.Tools

Hope this would help. :)

Answer 3

1. Make sure that this is available in your project.json file "Microsoft.EntityFrameworkCore.Tools.DotNet": "1.0.0-preview3-final".

2. Run the command in the package manager console

that's all it will work

Answer 4

Make sure you run VS as Administrator and have installed the following packages:

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

Answer 5

Scaffold command is part of dbcontext command in EF. Below are the details for successful scaffold:

Package references required:

<PackageReference Include="Microsoft.EntityFrameworkCore" Version="3.0.0"/>
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.0.0"/>
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.0.0"/>
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.0.0"/>

So our scaffold command should look like:

dotnet ef dbcontext scaffold "Server=localhost\SQLEXPRESS;Database=MyDatabase;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -o OutputDirectory

Your Server value might differ as per your Db server name. Replace MyDatabase with your Database name like master and OutputDirectory to the location you want your newly created scaffolded classes like Models folder.

Answer 6

Make sure you are using the right console, the "Package Manager Console". There is also a "Terminal" console which looks very similar, but doesn't work for this command. Package Manager Console can be found in View -> Other Windows (as of Visual Studio 2019, ver. 16.6.5)

Answer 7

I had installed Microsoft.EntityFrameworkCore.Tools from NuGet Package Manager and it was visible in the installed packages. But I kept getting this error.

Restarting Visual Studio (2019/Version 16.4.4) fixed it for me.

Answer 8

If you're using .NetCore 2.2 the command below works like a charm for me on either command prompt or Git Bash. Make sure that you are directly on the project folder before running the command.

For example C:\App\ProjectName:

 dotnet ef dbcontext scaffold "Server=.\;Database=Databasename;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -o Model

Answer 9

I ran into another cause of this error recently: NuGet itself was out of date.

Updating NuGet resolved the issue.

If Devanathan's answer doesn't work for you, check to make sure NuGet itself is up to date.

Answer 10

For me... when copy pasting the command from the microsoft docs, for some reason extra spacing was added around the hyphens.

Removing the hyphens fixed it:

wrong:

Scaffold - DbContext "Server=(localdb)\mssqllocaldb;Database=myDbName;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer - OutputDir Models

good:

Scaffold-DbContext "Server=(localdb)\mssqllocaldb;Database=myDbName;Trusted_Connection=True;" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

The docs also say if you receive this error, try restarting Visual Studio.

https://docs.microsoft.com/en-us/ef/core/get-started/aspnetcore/existing-db