What happened to CSharpMigrationsGenerator and SqlServerMigrationsSqlGenerator - entity-framework-core

Question

After upgrading an existing project from EF Core 5 to EF Core 6, some customizations would no longer compile, specifically customizations to the CSharpMigrationsGenerator and SqlServerMigrationsSqlGenerator classes. Although the namespaces are correct, Visual Studio underlines references to them and doesn't seem to know what I'm talking about. Looking at the EF Core source code, the classes are where they should be, so why can't I see them in my project?

Answer 1

This is a side effect of NuGet updating the package reference. The Microsoft.EntityFrameworkCore.Migrations.Design namespace comes from the Microsoft.EntityFrameworkCore.Design package, which wants to install itself like an analyzer.
After updating the reference, your csproj file will look like this:
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.0">
<PrivateAssets>all</PrivateAssets>
<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
</PackageReference>
This is incorrect. This is how you reference an analyzer. It makes the code in that package available to Visual Studio, but not to your code. What you want is a plain old package reference like this:
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="6.0.0" />
Fixing your csproj file will make the classes available to your code again.