EF Core Error - No project was found. Change the c

问题:

I am using Visual Studio 2015 and dotnet core and trying to develop an EF Core Code First project using Sqlite and this documentation / tutorial, which also uses Sqlite => NET Core - New Database

When I try to add an initial migration from the command line ( I am CD-ed into the folder that my data model project is located in) by issuing the following command

dotnet ef migrations add InitialMigration

...I get the following Error.

No project was found. Change the current working directory or use the --project option.

I even tried using the --project option like so.

> dotnet --project "C:\Shiva\EF\EFCFSqlite.Data.xproj"  ef migrations add InitialMigration

but that gives the following error.

Unknown option: --project
.NET Command Line Tools (1.0.0-preview2-003131)
Usage: dotnet [host-options] [command] [arguments] [common-options]

I noticed that the documentation is using .csproj file whereas my Project is showing a xproj file. Also the docs mention something about not using project.json anymore :(

Here's my project.json file.

{
  "version": "1.0.0-*",

  "dependencies": {
    "Microsoft.EntityFrameworkCore.Sqlite": "1.1.1",
    "Microsoft.EntityFrameworkCore.Sqlite.Design": "1.1.1",
    "NETStandard.Library": "1.6.1"
  },
  "tools": {
    "Microsoft.EntityFrameworkCore.Tools.DotNet":"1.0.0"
  },
  "frameworks": {
    "netstandard1.6": {
      "imports": "dnxcore50"
    }
  }

What has changed? Do we have no choice but to Install Visual Studio 2017 and start from scratch?? Is project.json and all this other stuff no longer honored?

Seems like a massive change to me if that's the case :(

回答1:

Instead of:

"tools": {
    "Microsoft.EntityFrameworkCore.Tools.DotNet":"1.0.0"
  },

try:

"tools": {
      "Microsoft.EntityFrameworkCore.Tools.DotNet": {
      "version": "1.0.0-preview3-final"
  }},

回答2:

sometimes you need to change the current directory in console/terminal eg:

PM> cd E:\Projects\CrossTest\
PM> dotnet ef migrations add InitialMigration

and Align your package versions. Either use preview1 packages or preview2. Mix of those are not supported.

回答3:

1. Add the nuget package Microsoft.EntityFrameworkCore.Tools
2. Add the nuget package Microsoft.EntityFrameworkCore.Design
3. Right-click your project file, select Edit and then add the following to the ItemGroup that contains PackageReference nodes

<DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="2.0.3" />

(You can find the latest version by finding it in the Nuget Package manager)

4. Open the Package Manage Console: Tools->Nuget Package Manager->Package Manager Console
5. Type cd {path where your csproj file resides} (this is important)
6. Now type dotnet ef migrations add InitialMigration

回答4:

It simply Means that

YOU ARE NOT IN CURRENT PROJECT DIRECTORY

I was facing the same issue when scaffolding existing database of MySql using this.

Command I was executing:

dotnet ef dbcontext scaffold "Server=123.1.1.1;Uid=abc;Pwd=abc;Database=myDB;Connection Timeout=20;Persist Security Info=False;Port=3306;Allow User Variables=True;Connect Timeout=120;" MySql.Data.EntityFrameworkCore -o Models

Causing the same error , then I checked current working directory inside package manager console and found incorrect.

In my case

Mean I was not in current project directory then after switching directory

cd SSGCApp

Now you are in project directory all good to run the Command.

回答5:

Just faced similar issue. Fixed by downgrading to 1.0.0-preview3-final

"tools": {
     "Microsoft.EntityFrameworkCore.Tools.DotNet": "1.0.0-preview3-final",    
}

and changing --project param to --startup-project

dotnet ef --startup-project <PATH_TO_PROJECT_DIRECTORY> migrations add <MIGRATION_NAME>

In global.json I also downgraded version to

 "sdk": {
     "version": "1.0.0-preview2-003131"
 }

This might be a temp workaround before migrating to csproj.

回答6:

The dotnet-ef command has moved.

You will need to add a reference to Microsoft.EntityFrameworkCore.Tools.DotNet AND Microsoft.EntityFrameworkCore.Design to your dependencies in project.json, then add Microsoft.EntityFrameworkCore.Tools.DotNet to the tools section and you should be good to go.

Cited from: http://errummwelluhh.blogspot.com