Tag Archives: EF

EF Core 8 Courses are Live on Pluralsight

Pluralsight, , , ,

I spent much of the fall and winter updating my three EF Core courses.

EF Core 8 Fundamentals is a brand new version of the course. The EF Core 6 Fundamentals and earlier versions remain as separate courses always available.

EF Core and Domain-Driven Design has also been updated to EF Core 8. This is what Pluralsight calls an “in-place” update. There is no longer a separate EF Core 6 and DDD course, but the new course , while focusing on EF Core 8, calls out important differences you may encounter if you are using EF Core 6 or 7.

EF Core: The Big Picture. This now uses EF Core 8 although it is relevant to previous versions again with shout outs to important differences.

You can find all of my courses, including “retired” courses like EF Core 5 Getting Started, on my Pluralsight author page.

Other courses in Pluralsight’s EF Core 6 path (there are multiple authors) are also getting updated to EF Core 8.

New EF Core and Domain-Driven Design Course on Pluralsight!

Data Access, DDD, dotNET, , , ,

MY NEW Pluralsight COURSE IS OUT! EF Core 6 and Domain-Driven Design. Yippee! I spent 3 months heads down on this (and years preparing for it!)

This happily aligns with a current 50% off sale on annual subscriptions.

Also note that as with *all* PS courses, they are limited to “expanded” library for the first few days but this will be part of the standard library (available to all) hopefully by the end of this week.

Short description
“Data persistence is important to your application workflow. This course will teach you how to use Entity Framework Core 6 and 7 effectively to persist data from your DDD designed software.”

Content
The module titles should give you a better flavor of this course:

  • Understanding Where EF Core 6 Fits Alongside DDD (Includes an overview of DDD)
  • Analyzing and Planning Our Domain (Strategic and tactical design walkthrough)
  • Exploring the Contract Bounded Context Solution
  • Adding the First EF Core DbContext
  • Tuning Default Mappings for the Data Model
  • Using Integration Tests to Validate Persistence
  • Reasoning About Many-to-Many Variations
  • Mapping Aggregates to Azure CosmosDB
  • Organizing Persistence Logic to Support DDD Design (Repositories, services, search and sharing data and events across bounded contexts)

Enjoy!

New on Pluralsight! EF Core 6 Fundamentals!

Data Access, , ,

I’m so excited to share with you that I have a new course on Pluralsight: EF Core 6 Fundamentals. I’ve been working on it for a while and it is the biggest course I’ve ever created. It is 7.5 hours long. It’s a lot more than the breadth of the previous Getting Started courses.  

And there’s an additional bonus. Pluralsight is having a sale on subscriptions right now. 33% off through May 12, 2022.

There are 16 modules if you count the course overview which is just a 1.5 minute “trailer” about the course. This is not just a refresh of the recent EF Core 5 Getting Started course. In fact, I retired the samurais and have introduced a book publisher as the domain this time. Below is the list of module titles for my new course.

I’ve also posted the sample code for the course in this repository on my Github account. 

  1. Course Overview
  2. Building Your First Application using EF Core
  3. Using EF Core 6 to Query a Database
  4. Tracking and Saving Data with EF Core
  5. Controlling Database Creation and Schema with Migrations
  6. Defining One-to-Many Relationships
  7. Logging EF Core Activity and SQL
  8. Interacting with Related Data
  9. Defining and Using Many-to-Many Relationships
  10. Defining and Using One-to-One Relationships
  11. Working with Views and Stored Procedures and Raw SQL
  12. Using EF Core with ASP.NET Core Apps
  13. Testing with EF Core
  14. Adding Some More Practical Mappings to Your Application
  15. Understanding EF Core’s Database Connectivity
  16. Tapping into EF Core’s Pipeline

I’d also like to give a shout out to my friend and fellow Pluralsight author, Roland Guijt, who acted as tech reviewer as I created this course. His feedback and insights were invaluable as is evident not only in the final version of my course, but in his own courses on ASP.NET Core, C# and more.

Logging in EF Core 2.2 Has a Simpler Syntax–More like ASP.NET Core

Data Access,

Logging EF Core’s memory operations and SQL operations has evolved a few times since EF Core arrived. It takes advantage of the same underlying features that ASP.NET Core uses. If you are using ASP.NET Core, logging is baked in and it is really simple to turn it on for EF Core and add filtering. See Shawn Wildermuth’s blog post about EF Core logging in ASP.NET Core.

But if you aren’t using ASP.NET Core, it’s a little more complicated. Not terribly, but still there’s some extra work to do. It involves setting up an ILoggerFactory in your DbContext and defining any filters at the same time.

I wrote an article about this (with the focus being on taking advantage of the various available filters for EF Core logging) in MSDN Magazine earlier this …oh wait, it’s Jan 1, so I can say “last  year”.  Data Points – Logging SQL and Change-Tracking Events in EF Core. I also used it heavily in my EF Core 2 Getting Started course, EF Core 2:Mappings and EF Core 2.1: What’s New courses on Pluralsight. (Note that I’ve updated the sample code for the Getting Started course to EF Core 2.2 and put it on GitHub at github.com/julielerman/PluralsightEFCore2GettingStarted)

My article and courses were using Console apps to demonstrate EF Core behavior and therefore the ConsoleLoggerProvider to tie the logger to the console. Note that the Data Points article contains a lot of good details about the various types of filtering. So you can use the new syntax (below) to specify that there should be a filter, but be sure to read the article to learn about the flavors of filtering and what type of details you’ll be able to see based on the choices you make.

But the logging API has continued to evolve and is providing some of the same shortcuts that ASP.NET had created. And the ConsoleLoggerProvider has been deprecated. The API is not part of EF Core. It’s part of .NET Core. Both EF Core and ASP.NET Core use it.

If you are using EF Core 2.2, the syntax has changed (simplified) and it’s going to get even more streamlined in 3.0.

In fact, if you use the earlier syntax with 2.2, you’ll get a warning about the ConsoleLoggerProvider:

Obsolete(“This method is obsolete and will be removed in a future version. The recommended alternative is using LoggerFactory to configure filtering and ConsoleLoggerOptions to configure logging options.”)

For a point of comparison, here is an example of using theold syntax to turn on logging, only show logs related to database commands and only show messages that are tagged as “Information”.

EF Core 2.0 & 2.1 Logic

public static readonly LoggerFactory MyConsoleLoggerFactory
            = new LoggerFactory(new[] {
              new ConsoleLoggerProvider((category, level)
                => category == DbLoggerCategory.Database.Command.Name
               && level == LogLevel.Information, true) });

Once your logger factory field is defined in the context class you tell the DbContext to use it when configuring.

protected override void OnConfiguring
  (DbContextOptionsBuilder optionsBuilder)
{
  var connectionString = 
    ConfigurationManager.ConnectionStrings["WPFDatabase"].ToString();
  optionsBuilder
    .UseLoggerFactory(MyConsoleLoggerFactory)
    .EnableSensitiveDataLogging(true)
    .UseSqlServer(connectionString);
}

So it’s the creation of the logger factory whose syntax is a little convoluded. The newer API follows how ASP.NET Core lets you filter with an AddFilter method that takes the filters as parameters. No lambdas needed. Also configuring the filter is a separate bit of logic that tellig the logger that it should be tied to the console.

EF Core 2.2 Logic

With EF Core 2.2, you can set up the logger factory in the constructor or another method as long as it’s available when you are configuring the option builder. I’m creating it in a method then using that method as a parameter of UseLoggerFactory. I’m still filtering on showing only database commands and log details flagged as Information.

private ILoggerFactory GetLoggerFactory()
{
  IServiceCollection serviceCollection = new ServiceCollection();
  serviceCollection.AddLogging(builder =>
         builder.AddConsole()
                .AddFilter(DbLoggerCategory.Database.Command.Name, 
                           LogLevel.Information)); 
  return serviceCollection.BuildServiceProvider()
          .GetService<ILoggerFactory>();
}

and then I’m calling GetLoggerFactory() in the UseLogging method on the optionsbuilder:

optionsBuilder.UseLoggerFactory(GetLoggerFactory())

Packages and References

In order to use the AddConsole() method, you still have to use the Microsoft.Extensions.Logging.Console package that the earlier ConsoleLoggerProvider was in. However, you do not need a using statement for the namespace (as you did for the ConsoleLoggerProvider).

EF Core’s IsConfigured and Logging

Data Access,

I got a little confused about some behavior today and finally realized my mistake so thought I would share it. This mostly happens in demo apps that I’m building that are not using  ASP.NET Core.

In these cases, I typically stick the DbContext provider configuration in the OnModelConfiguring method. For example, if I’m using SQLite, then I would specify that in the method as such:

protected override void OnConfiguring
 (DbContextOptionsBuilder optionsBuilder)
{
   optionsBuilder.UseSqlite (@"Filename=Data/PubsTracker.db");
}

I also have been using the logging factory a lot. After defining it, I also configure it. I hadn’t thought much about where I was placig it so added it in randomly.

protected override void OnConfiguring 
  (DbContextOptionsBuilder optionsBuilder)
{
  optionsBuilder.UseLoggerFactory (MyConsoleLoggerFactory);
  optionsBuilder.UseSqlite (@"Filename=Data/PubsTracker.db");
}

Then I added in some tests to had to avoid the SQLite provider if the InMemory provider was already configured, so I wrapped the UseSqlite method with a check to see if the options builder was already configured.

protected override void OnConfiguring
  (DbContextOptionsBuilder optionsBuilder)
{
  optionsBuilder.UseLoggerFactory (MyConsoleLoggerFactory);
  if(!optionsBuilder.IsConfigured)
  {
    optionsBuilder.UseSqlite (@"Filename=Data/PubsTracker.db");
  }
}

But my logic wasn’t working. I was running some migrations but they were suddenly not recognizing the UseSqlite method. I’ve used this pattern so many times. It took me a while to realize what was going on. The UseLoggerFactory is a configuration!

I just had to move the UseLoggerFactory logic after the IsConfigured check and all was well.

This is one of those dumb things that seems so silly you wouldn’t imagine someone else would make such a mistake. But since it bit me, I thought it was worth sharing mostly for the sake of the next coder who is trying to solve the same problem.

The Secret to Running EF Core 2.0 Migrations from a NET Core or NET Standard Class Library

Data Access,

I have had two people that watched my Pluralsight EF Core Getting Started course (which will soon be joined by an EF Core 2: Getting Started course) ask the same question, which mystified me at first.

The were running migrations commands which caused the project to compile, but the commands did not do anything. For example, add-migration didn’t add a migration file. get-dbcontext did not return any information. The most curious part was there was no error message! I was able to duplicate the problem.

With EF6 it was possible to use migrations from a class library with no exe project in sight. EF Core migrations can run from a .NET Framework or .NET Core project but not .NET Standard. It needs a runtime. A common workaround is that even if you haven’t gotten to the UI part of your app yet, to just add a .NET Core console app project to the solution, add the EF Core Design Nuget package to it and set it as the startup project. But it’s still possible to do this without adding in a dummy project.

We already knew about the multi-targetting fix which solved an error when you try to run migrations from a .NET Standard library. But even with that fix in place, we were getting the mysterious nothingness.

The answer to the question was buried in a GitHub issue and in comments for the Migrations document in the EF Core docs. This same solution solved a problem I was having when trying to use migrations in a UWP app (again, not .NET Core or .NET Framework) that used a separate class library to host its DbContext.

I’m writing this blog post to surface the solution until it is resolved.

The solution that we used with EF Core 1.0 in order to run migrations from a .NET Standard library was to multi-target for .Net Standard (so you can use the library in a few places) and .NET Core (so you can run migrations).

That means replacing

<PropertyGroup>       
  <TargetFramework>netstandard20</TargetFramework>
</PropertyGroup>

with

<PropertyGroup> 
  <TargetFrameworks>netcoreapp2.0;netstandard2.0</TargetFrameworks>
</PropertyGroup>

Notice that the attribute name is now plural and there is a semi-colon between the two SDKs.

But there’s one more secret which is not in the documentation.

For .NET Standard 2.0 (and EF Core 2.0), you also need to add the following to csproj.

<PropertyGroup>
 <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles></PropertyGroup>

Now with the DbContext project set as the startup and ensuring that the package manager console (or command line) are pointing to the same project, your migration commands will work.

Thanks to Christopher Moffat who found the solution in the GitHub issues and shared it in the comments on the EF Core Package Manager Console Tools document.

Screenshot for Tony ..see my comment in reply to your comment below.

First Foray into .NET Core 2.0

Data Access, , ,

I have to start somewhere so I started wtih super baby steps. Downloading the .NET Core 2 nightly build and trying to create a simple console app. Right away I failed miserably. The reason? The nightly builds have already jumped the shark! They are working on 2.1.0 and I accidentally grabbed that. And that was a little too bleeding edge for me.

There is a docker image that you can use quite easily but I wanted to try CLI, VS Code and Visual Studio. Therefore I wanted to just install the bits right on my machine.

What I’ll show you are  my first tests I did on macOS and on Windows 10. I like to do this just to make sure things are actually running properly. Note that on macOS, I just installed this new version directly on my machine where I have other versions of .NET Core. Key is that there is no production work on there dependent on other versions, so I won’t mess up anything important. The versions can live side by side. It’s just that for someone like me who “knows enough to be dangerous”, it’s easy to get tangled up with the versions even though I know tricks like creating a local nuget.config file and also specifying a version in global.json. On Windows, however, I am using a clean VM that has no other versions of .NET on it. That’s the smart way anyway. Although I did try the not smart way of installig it on my machine that already has all kinds of versions of all kinds of frameworks on it and even with my versioning tricks, I could not get 2.0.0 to do a restore or build.

I mentioned above that I originally downloaded the wrong version of the SDK. (Note that the typical SDK install also includes the runtime….so I got the wrong versoins of both. You can read the gory details of that in this GitHub issue which I kept updating as I sorted the problem out.) I want to stick with .NET Core 2.0.0. The installer for that is tucked away in a branch of github.com/dotnet/cli rather than grabbing the absolute latest from the master. Instead go to https://github.com/dotnet/cli/tree/release/2.0.0. There is a solid 2.0.0 version — 2.0.0-preview2-006391. That’s the one I’m using on Windows and macOS.

2017-06-11_12-23-16.jpg

Make Sure NuGet Knows Where to Find Packages

You can update your global NuGet.Config before creating projects. Alternatively, you can create a project and then add a local NuGet.config file to it.

On Mac, the global config file at [user]/.nuget/NuGet. Here s a screenshot if like me, macOS is not your primary platform and you still struggle with these things.

2017-06-11_12-32-15.jpg

In Windows, it’s at %APPDATA%\NuGet\.

I keep a link to the “Configuring NuGet behavior” doc handy for when I forget where to find that.

I added these two keys to my PackageSources section:

<add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />

<add key="dotnet-core" value="https://dotnet.myget.org/F/dotnet-core/api/v3/index.json"/>

 Now it’s time to create a project

I’m on the Mac, so, to Terminal we will go.

I’ve created a new folder called EFCore20 – I know this is .NET Core, but eventually I plan to add in EF Core 2.0 as well.
My plan is to create a .NET Core console app (this will rely on netcoreapp2.0) and a library. The libray will be based on the netstandard2.0 library . That means its a library I’ll be able to use from a huge variety of apps, including .NET 4.6.1 based apps. EF Core 2.0 will also rely on .NET Standard 2.0, so any app or API that can consume netstandard, can also consume EF Core 2.0. Read more about that in this EF Core 2.0 announcement on GitHub.

I created one folder for each inside the EFCore20 folder:

netcore2console
netstandard2lib

Then I cd’d into the netcore2console app to create that app with the command:

dotnet new console.
That’s all it takes. This creates a tiny little Hello World app. The dotnet new command will also perform a dotnet restore after creating the files. This is the first moment you will see if things are wokring again. If the restore fails, it will tell you immediately.
This is the message I got when had things misaligned:
Error message: error MSB4236: The SDK ‘Microsoft.NET.Sdk’ specified could not be found.
The “specified” SDK is the currently installed version of whatever SDK you are referencing. In my case, the default for dotnet enw console is “dotnetcore” with the version being whatever version is installed.
Most likely the problem is that  you haven’t provided the correct URI for dotnet to find the proper NuGet packages.
If you don’t want to mess with the global config, you can create a local NuGet.config file in the folder with the app. In it’s entirety, it would look like:
<?xml version="1.0" encoding="utf-8"?>
 <configuration>
  <packageSources>
   <addkey="nuget.org"value="https://api.nuget.org/v3/index.json"protocolVersion="3"/>
   <addkey="dotnet-core"value="https://dotnet.myget.org/F/dotnet-core/api/v3/index.json"/>
  </packageSources>
</configuration>
Even though dotnet new will call restore, I like to call
dotnet restore
explicitly. (Control freak)
If it restored correctly, then the next step for validation is
dotnet build
And hopefully that gives you no errors as well. It shouldn’t.
Finally,
dotnet run
should result in spitting out
Hello World!
And now I know it’s working. Silly little bit but I want to verify this before I waste my time writing a bunh of code that isn’t going to run because I don’t even have .NET Core installed properly.
Another point of interest is what files were created by dotnet new console.
It’s easier to see them if I open them up in Visual Studio Code which I can do by typing
code .
There are only 2 files. The csproj with the project metadata and a program file.  The csproj file says that the target framework is netcoreapp2.0.

2017-06-11_14-09-46

The program file just spits out Hello World when it starts up.
2017-06-11_14-10-17
Here is a screenshot of all of the steps at the command line from dotnet new console to the Hello World! output including my extra dotnet restore. Another thing I like about the explicit restore is that it’s showing me more detailed info about the restore.
2017-06-11_14-03-19
Next I want to make sure I can get a .NET Standard library also working.
Still in the terminal (or console or PS if you’re on Windows), I now get into the 2nd sub folder, EF Core2/netstandardlibrary. dotnet new library defaults to using netstandard for the library. So that makes it easy.
dotnet new library
The library is created and the packages it needs are restored.
Here are the default contents of this new library, again, shown in VS Code.
Ntice that its csproj says the target framework is netstandard2.0.2017-06-11_14-16-09
And there’s an empty class file.
2017-06-11_14-18-12
I’ll modify the class to add a public method that returns a string: “Why, Hello There!”.
2017-06-11_14-22-01

Now I’ll go into the csproj for the console app and give it a project reference to the library. The intellisense does not (yet?) help me with this and my memory sucks*, so I head to Nate McMaster’s handy project.json to csproj mind mapper aka Project.json to MSBuild conversion guide to remind myself the syntax of a project reference. I add this below the property group section in the console app’s csproj file

 

<ItemGroup>
  <ProjectReference Include="..\netstandard2lib\netstandard2lib.csproj"/>
</ItemGroup>
Running dotnet restore and dotnet build again will help identify if you’ve got a typo in there. I often do.
Now I’ll modify the Program.cs file to also call output the resultls of caling the HiYa method from my library:
2017-06-11_14-31-39

And then back out to my terminal window (though I can also do it inside VS Code’s built-in terminal). I dotnet build the library and then change to the console folder. Rebuild that and run it and …voila

➜  netcore2console dotnet run

Hello World!

Why, Hello There!

➜  netcore2console

So now I know that .NET Core 2 (preview from a nightly build) is running properly on my machine and that I can create and use a .NET Standard 2.0 library. That means I can go ahead and confidently start creating a .NET Standard 2.0 library to host some EF Core 2.0 logic.

I also repeated this entire thing on my Windows machine. Not only does that let me know I can use this version of .NET Core there, but I will also do some work from within Visual Studio with the .NET Core 2.0 preview.

*(duh, I should just make myself a snippet in VS Code!)

Changes to EF Core With the RTM of VS2017 and Tools

Data Access, ,

When Visual Studio 2017 released today a few other things happened that are relevant to Entity Framework Core.

For more on EF Core, watch my EF Core: Getting Started course on Pluralsight.

EF Core Migrations Tools Release

First – something we were prepared for – the .NET Core SDK was also released. The last stable version was 1.0.0-preview2-1-003137. It’s now simply 1.0.0. Along with this, its dependent tooling, including EF Core Tools for PowerShell and dotnet were also released. As the .NET Core support evolved from project.json to msbuild, the EF Core tools split . We have been using 1.0.0-preview4 (for .NET and project.json) and 1.0.0-msbuild3 for msbuild/csproj support.

Now the tool packages are 1.1.0 (Tools) and 1.0.0 (Tools.DotNet)

For PowerShell support: Microsoft.EntityFrameworkCore.Tools 1.1.0
For dotnet CLI support: Microsoft.EntityFrameworkCore.Tools.DotNet 1.0.0

In Visual Studio 2015 (for full .NET projects) and Visual Studio 2017 (shown here, for full .NET or .NET Core projects), the Package Manager will show the RTM versions:

image

Notice that I do not have “Include prerelease” checked.

If using PMC to install, it’s just

install-package Microsoft.EntityFrameworkCore.Tools

That’s for the PowerShell tools, otherwise, add .DotNet to the name.

But notice that you no longer need to add the –pre.

When using the CLI version of the tools, the command

dotnet ef –version

results in

Entity Framework Core .NET Command Line Tools 1.0.0-rtm-10308

Changes to Migrations Commands

As the tools evolved through the previews, some details changed for example, the scaffolding command got smarter.

But one change that is notable is with respect to EF Core in class libraries. You still need to point to an executable project (exe or test) to run most of the commands, but now you can at least just use “dotnet ef” to get the help file without having to set the –startup-project parameter. There are a few other commands that will run without knowledge of the startup project. You can read more about this in this GitHub thread. Check some of the later comments by Brice Lambson as he worked on evolving the commands.

EF Core 1.1.1 – Patch

This was a more subtle part of the release. Even though the 1.1.1 milestone on GitHub had 30 bug fixes that are all closed , there hadn’t been any mention that this was going to get pushed out and the milestone had no target date on it. Though I had my suspicions! Here’s a screenshot I happened to take on March 5.

image

And yes, the newest version of the EF Core packages is now 1.1.1. These are bug fixes …as the increment suggests.  Most of them are edge cases, but regardless, you should definitely update your EF Core packages to ensure you have these latest fixes. If you’re creating new projects, 1.1.1 is what you’ll see available from NuGet.

Note: there was a regression introduced in EF Core 1.1.1 that is targeted to get fixed with the next patch. You can read about this issue here: http://stackoverflow.com/questions/42708522/loading-related-data-aspnet-core-1-1

You can learn much more about EF Core in my EF Core: Getting Started course on Pluralsight.

Troubleshooting the dotnet ef command for EF Core Migrations

Data Access, ,

Updated March 7, 2017 after Visual Studio 2017 was released.
Also, keep in mind that I have been updating this post (and will continue to do so) as I discover new ways people are hitting problems with dotnet ef.

When using EF Core in a .NET Core app (ASP.NET Core or other app sitting on .NET core), it’s easy to run into a problem when attempting to use EF Core migrations at the command line. The most common one is

No executable found matching command "dotnet-ef"

A Note If Your Coming from My Pluralsight EF Core Course

Microsoft supports developing .NET Core apps in VS2017. The tooling for VS2015 is outdated and there are no plans to bring them up-to-date for the new csproj support. I recorded my Entity Framework Core: Getting Started  course on Pluralsight while VS2017 was still in beta. While I did recreate the VS2017 demos in RC3 right before we published the course, we chose to leave the  rest of  the .NET Core demos that are in VS2015 alone.  VS2015 only supports project.json and the project templates set you up for .NET Core 1.0, not .NET Core 1.1. So in the course means that we’re stuck with project.json support and tooling that’s not quite aligned. But Pluralsight and I both agreed that it made sense not to ALSO force users to the bleeding edge, not even released VS2017 for the demos. The course’s focus is on EF Core, so as long as I could hand-hold users through the project.json setup stuff without the need to make them expert at that, it was the right way to go.

Of the nearly 2000 who have already watched the course since it’s release less than 2 weeks ago,  a few people ran into some confusion with the versioning and getting the “no executable found” message. I worked through these with them but wanted to write down the suggestions I’d made and have a single blog post I could point to.

Problems You May Encounter with ‘dotnet ef’

While some of these notes are specific to the project.json use in the course, I’ve also added tips for using dotnet ef with the newer csproj/msbuild support.

There are a few key things to watch out for.

  1. The current stable tooling for EF Core migrations is split into two packages.
         Microsoft.EntityFrameworkCore.Tools is for PowerShell
        Microsoft.EntityFrameworkCore.Tools.DotNet is for the CLI (dotnet commands)
    Be sure you’ve referenced the Tools.DotNet version of the package so that you have access to the CLI commands. If you’re following my course, that’s explained.
  2. dotnet ef only works in .NET Core projects. If your project targets the full .NET framework, then you’ll need to use the PowerShell commands e.g. add-migration, update-database.
  3. Make sure that you are running the command from the folder that contains the project where the Tools package is referenced. This is explained in the course demos, but still a step you may overlook in your excitement!
  4. If you are using project.json*, make sure that you have the Tools.DotNet package in the Tools section, not the dependencies section. After March 7 release, this will just be “1.0.0”.
    *Going forward, you should only be using project.json with .NET Core 1.0 projects. If you are using the current .NET Core (1.1+) you should be using csproj/msbuild.

    "tools": {
   "Microsoft.EntityFrameworkCore.Tools.DotNet": "1.0.0"
 }
  5. If you’re using csproj/msbuild, make sure the tools package is listed in the DotNetCliToolsReference tag.  After March 7 release, this will just be version “1.0.0”.

    <DotNetCliToolReference   
    Include="Microsoft.EntityFrameworkCore.Tools.DotNet"
    Version=”1.0.0” />
  6. If you’re using csproj/msbuild, make sure the casing is correct if you’re manually adding that package in csproj! I’ve seen people get tripped up by typing Dotnet rather than DotNet.
  7. It’s possible that you have to Tools correctly placed but your IDE did not trigger a dotnet restore. So you may need to do that manually. Here’s an example where that bit someone. https://github.com/aspnet/EntityFramework/issues/7801
  8. You shouldn’t be using an RC of VS2017 at this point but I’m leaving this one here.
    If you are using an older Release Candidate of Visual Studio 2017 (before RC3) , the CLI tooling was not yet aligned with the msbuild support so with that version, you have to use the PowerShell commands to do migrations. Therefore you have to use the Tools package and work in the package manager console, not the command line.

    <DotNetCliToolReference   
    Include="Microsoft.EntityFrameworkCore.Tools"
    Version="1.1.0-preview4" />

    As of  VS2017 RC3 (which is what I show in the last module of the course) it was possible to use msbuild3 as shown in point #4 above and the CLI commands. After March 7 release, this will just be “1.0.0”.

  9. Be sure you’re targeting a relational database. Migrations only work with those and not, for example, InMemory. A twitter friend accidentally ran into this problem and was getting the “no executable found” error message.
  10. Make sure that the version of the EF Core tools you are using aligns with the version of .NET Core on your machine.

In my EF Core course, I’m using EF Core 1.1 and for EF tools and in all but the last module, I’m using Microsoft.EntityFrameworkCore.Tools.DotNet 1.0.0-preview4. (I’m in the process of  updating the course to use the new 1.0.0 package)

You’ll need .NET Core 1.1 installed and the related dotnet SDK – which is not numbered as simply. Today the  .NET Core SDK tools are still in preview so the version number of the current “stable” build that goes with .NET Core 1.1 is 1.0.0-preview2-1-001377.  

Note that on March 7  when VS2017 has its official release, the .NET Core SDK tools will also be released so the versions will just be normal numbers like 1.0.0.

Here’s an example of what the dotnet ef command will tell you if you don’t have .NET Core 1.1 installed:

The specified framework 'Microsoft.NETCore.App', version '1.1.0' was not found.
 - Check application dependencies and target a framework version installed at:
 C:\Program Files\dotnet\shared\Microsoft.NETCore.App
 - The following versions are installed:
 1.0.1
 - Alternatively, install the framework version '1.1.0'.

You can get the correct version via the download grid at microsoft.com/net/download/core. The grid only exposes stable releases. If you’re looking for nightly builds (which at this time you need for using the csproj support), there’s a link to those just below the grid.

The set of downloads you get via the LTS button is for .NET Core 1.0.3. The Current button gives you the latest stable versions. The SDK button gets you the Runtime + SDK, whereas the Runtime button gives you ONLY the runtime.

The SDK installs will give you the SDK and the runtime. When you’ve selected the SDK set of installs, it says that it’s .NET Core 1.0. That’s referring to the version of the SDK. It will also install both the .NET Core 1.0 and .NET Core 1.1 runtimes. That single SDK is able to work with both of the runtimes. I’m on Windows x64 so my download is the first one on the list…the Windows x64 installer.netcoresdk10

Just as an FYI, if you select the Runtime set of downloads, then you will only be getting a specific version of a runtime and not the SDK.

netcore11runtime

After it’s installed, typing dotnet will show you that you the runtime version that your machine is running by default. That’s the later one. After installing the 1.0 SDK with both runtimes, dotnet tells me I’m running Version 1.1.0 of the runtime. 

 dotnet –version gives you the version of the SDK. That’s already showing me that there was a patch because the result says “1.0.1”.

If you installed this new SDK but are still seeing the old SDK version (1.0.0-preview2-001313), that is likely because that version is specified in the global.json file of your solution. That shouldn’t create a problem for using the migration commands, but it’s a good idea to have the correct version listed in global.json.

Some additional tips for you!

Commands can only run from an executable/test project

In my Pluralsight EFCore course, I have the DbContext in its own class library project. So when running dotnet ef, after solving all of the above problems, you’ll get a new message which is just pointing out that the commands depend on an executable to run. That message looks like this:

Could not invoke this command on the startup project 'TestEFCore.Data'. This version of the Entity Framework Core .NET Command Line Tools does not support commands on class library projects in ASP.NET Core and .NET Core applications.

In my case, I wasn’t ready to add a UI or test to the solution,  so I added a minimal console app just to cover this need. And it needs to reference the project with the DbContext. Once that’s sorted, you can use the —startup-project parameter of the dotnet ef command to point to that project. While I show all of this in my course, you can also see that in my MSDN Magazine article here: msdn.microsoft.com/magazine/mt742867

This will get a touch easier with the msbuild version of the EF Core tools. With the newer tooling, you’ll at least be able to run dotnet ef to get the command’s help without pointing to a startup-project, although to run sub commands, you’ll still need to specify the startup project.

Installing the EF Core Tools via NuGet in Visual Studio 2015

One of the viewers of the course reported a strange problem. He was able to add the EF Core Tools package in project.json and use the migrations from the CLI as expected. But if he attempted to add the package from the NuGet Package Manager or the Package Manager Console instead, he was back to the old ‘No executable found matching command “dotnet-ef”‘ error.

He finally noticed that there were errors when NuGet attempted to download the package. But in his IDE the errors were subtle, so he was unaware that the tools package was not installed. Here’s a screenshot he shared:

frsBKTFTRSjBGOFFZDJ6_nugetmanager

I figured out how to get myself into a similar bind and got a much more helpful error message:

2017-02-27_17-08-52

Package 'Microsoft.EntityFrameworkCore.Tools.DotNet 1.1.0-preview4-final' uses features that are not supported by the current version of NuGet. To upgrade NuGet, see http://docs.nuget.org/consume/installing-nuget.

Even though Visual Studio extension manager did not indicate an available update AND it listed my NuGet Package Manager version as 3.5 (the latest), I learned that the team responsible for this extension had temporarily stopped pushing notifications for updates! That change is noted in the “No Auto Updates” section of this blog post: http://blog.nuget.org/20161027/Announcing-NuGet-3.5-RTM.html

So I had to explicitly download the latest VSIX (ignoring the fact that it seemed to have the same version # as the one I had installed!) from the NuGet  distributions page. After installing that, it resolved the problem of installing the EF Core tools package from the Package Manager and Package Manager Console.

2017-02-27_17-14-46

There’s a sneak peek at EF Core with msbuild in VS2017

A few people mentioned to me that they decided to go straight to VS2017 when working through the demos in the course. And they also said they were confused by some differences and had to do some research. I know for sure that one of these devs was kicking himself when I asked if he had watched the VS2017 demo I did at the end of the course before trying to VS2017 along with the early demos. (His answer was “umm, now you tell me!”)  It’s listed in the table of contents for the course. So if you take a peek at that first, I think doing all the demos in VS2017 will be a lot easier! I am currently in the process of updating the VS2017 demos to use the RTM and latest tools.

Hope this helps!

Entity Framework Core: Getting Started on Pluralsight

Data Access, ,

I’m happy to share a new course on Pluralsight with you – Entity Framework Core: Getting Started.

Here’s how I described it in the trailer:

Most software – whether for business or entertainment – is driven by data that users need to interact with. In Entity Framework Core: Getting Started, you will learn how to use Microsoft’s modern data access platform, Entity Framework Core. You will learn how to build data models, use EF Core to bridge your software with  your data store and how to incorporate all of this into desktop, mobile and web applications. When you’re finished with this course, you will have a foundational knowledge of Entity Framework Core that will help you as you move forward to build software in .NET, whether you are targeting Windows, OS X or Linux. Software required: Visual Studio 2015 or Visual Studio 2017.

pluralsight course

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Here is the list of modules in the course. You can see the titles of various clips in each module on Pluralsight.

To see the full list of my courses on Pluralsight, go to pluralsight.com/authors/julie-lerman