Migration from ASP.NET Core 3.0 to 3.1

On December 3rd .NET Core 3.1 was released which included a new release of ASP.NET Core 3.1 and Entity Framework Core 3.1. This post is going to walk through updating the Contacts API project from the refreshed ASP.NET Basics series. All the changes I made came from Microsoft’s Migrate from ASP.NET Core 3.0 to 3.1 doc.

The code before any changes can be found here.


If you are a Visual Studio user you can get .NET Core 3.0 by installing at least Visual Studio 16.4. For those not using Visual Studio, you can download and install .NET Core 3.1 SDK from here. As with previous versions, the SDK is available for Windows, Linux, and Mac.

After installation is complete you can run the following command from a command prompt to see all the versions of the .NET Core SDK you have installed.

dotnet --list-sdks

You should see 3.1.100 listed at a minimum.

Project File Changes

Right-click on the project and select Edit projectName.csproj.

Change the TargetFramework to netcoreapp3.1.



Next, update all your packages to the new versions. This is going to vary greatly based on your project. This can be done manually in the csproj file or via the NuGet UI if you are using Visual Studio. The following are the changes from the sample project.

<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.0.0">
<PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.0.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.0.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.0.0">
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="3.0.0" />
<PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="1.2.0" />
<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.0.0" />
<PackageReference Include="NSwag.AspNetCore" Version="13.1.3" />

<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="3.1.0">
<PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.1.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.1.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.1.0">
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="3.1.0" />
<PackageReference Include="Microsoft.IO.RecyclableMemoryStream" Version="1.3.2" />
<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.1.0" />
<PackageReference Include="NSwag.AspNetCore" Version="13.1.6" />

Wrapping Up

The move from 3.0 to 3.1 is drop-dead simple which is not surprising since it has only been a few months since the release of 3.0. It is important to move to 3.1 as soon as you can since it is the long term service version and will be supported for at least the next 3 years where 3.0 will lose support within months.

Also published on Medium.

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