9.0.6 throws PendingModelChangesWarning with IdentityDbContext<T>

[MaximG1234]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

I have just upgraded my EF (identity) project to 9.0.6 and started running into the PendingModelChangesWarning error. In the process of debugging it I appear to have stumbled across what appears to be a bug in the implementation as it stands.

Not sure where this is most appropriate to log so I am going to log it both in EF core and the aspnetcore github.

Also this error message is awful, surely you can provide more information about specifically what is wrong?

Expected Behavior

No response

Steps To Reproduce

The bug appears to be very easy to reproduce.

Create a new database context

public sealed class DatabaseContextTest(DbContextOptions<DatabaseContextTest> options) : DbContext(options) {}

run your first migrations:

dotnet ef migrations add First_Migration

Run: await dbContext.Database.MigrateAsync();

Seems to work fine.

Modify this back to what I essentially had:

public sealed class DatabaseContextTest(DbContextOptions<DatabaseContextTest> options) : IdentityDbContext(options) {}

or more specifically

public sealed class DatabaseContextTest(DbContextOptions<DatabaseContextTest> options) : IdentityDbContext<ApplicationUser>(options) {}

public class ApplicationUser : IdentityUser {}

run your first migrations:

dotnet ef migrations add First_Migration

Run: await dbContext.Database.MigrateAsync();

and you get an exception.

Exceptions (if any)

An error was generated for warning 'Microsoft.EntityFrameworkCore.Migrations.PendingModelChangesWarning': The model for context 'DatabaseContextTest' has pending changes. Add a new migration before updating the database. See https://aka.ms/efcore-docs-pending-changes. This exception can be suppressed or logged by passing event ID 'RelationalEventId.PendingModelChangesWarning' to the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or 'AddDbContext'.

.NET Version

.NET 9

Anything else?

No response

[martincostello]

I assume you're upgrading from .NET 8, in which case you're hitting a breaking change made by EFCore in .NET 9: https://learn.microsoft.com/ef/core/what-is-new/ef-core-9.0/breaking-changes#high-impact-changes

[MaximG1234]

Hi @martincostello, appreciate the response but I don't think this is correct.

As mentioned I have created a completely new empty project (and new database) using the steps above. The new project contains no existing migrations or anything else that would define it as an 'upgrade'.

Perhaps I am missing something.

[martincostello]

My main point was that I'm fairly sure that it's an EFCore thing not an ASP.NET Core thing (for example your suggestion to change the error message would go there).

There's a bunch of discussion in this issue I opened about the change last year: dotnet/efcore#34431

[MaximG1234]

@martincostello

Yep cheers, appreciate your help/comment. I am aware of this breaking change and your thread but based on how I am interpreting this change, specifically:

'If the model has pending changes compared to the last migration an exception is thrown when dotnet ef database update, Migrate or MigrateAsync is called'

Seems to not be applicable to the scenario above or to the original problem that I ran into. In my initial scenario I don't believe I had any pending changes (although this can be harder to confirm once you have a lot of code) but in my example above its literally a completely fresh DbContext and empty database.

[martincostello]

I'm not disputing that, what I'm saying is that it's an EFCore issue (dotnet/efcore), not an ASP.NET Core issue (this repo).