Exception while using unique clustering key

[Morasiu]

Bug description

While saving collection, which has separate Clustering key and a composite made with Guid and enum I get a circular dependency exception.

Saving is simple and look like this:

testFromDb.Categories = new List<TestCategory>()
{
    new TestCategory()
    {
        Category = Category.Basic,
    },
    new TestCategory
    {
        Category = Category.Pro,
    }
};

dbContext.SaveChanges(); // Exception here

Tips which my team discovered:

• if Category is type of string it works (not sure about it)
• if modelBuilder.Entity<TestCategory>().HasIndex(x => x.ClusteringKey).IsUnique().IsClustered(); is done WITHOUT .IsUnique() it works
• only fails if there is more than one category updated

Here is a full repo with docker-compose file, migrations and data seeding for you to easily debug this error :)

EFCoreCompositeKeyClustering.zip

Your code

using Microsoft.EntityFrameworkCore;

// Use `docker compose up -d` to run the SQL Server container

var dbContext = new ApplicationDbContext();
dbContext.Database.EnsureCreated();

// BUG BELOW

var testFromDb = dbContext.Tests.Include(x => x.Categories).First();
testFromDb.Description = "New description";
testFromDb.Categories.Clear();
testFromDb.Categories = new List<TestCategory>()
{
    new TestCategory()
    {
        Category = Category.Basic,
    },
    new TestCategory
    {
        Category = Category.Pro,
    }
};

dbContext.SaveChanges(); // Exception here

Console.WriteLine("IT WORKS!");
// BUG END (Not the village from Hobbit)

public class Test
{
    public Guid Id { get; set; }
    public string Description { get; set; }
    public int ClusteringKey { get; }
    public ICollection<TestCategory> Categories { get; set; } = [];
}

public class TestCategory
{
    public Guid TestId { get; set; }
    public Category Category { get; set; }
    public int ClusteringKey { get; }
}

public enum Category
{
    Basic,
    Pro,
    SuperPro
}

class ApplicationDbContext : DbContext
{
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder
            .UseSqlServer("Server=tcp:127.0.0.1,1433;Initial Catalog=TestDb;Persist Security Info=False;User ID=sa;Password=P@ssword1234;MultipleActiveResultSets=False;Encrypt=True;TrustServerCertificate=True;Connection Timeout=30;");
    }

    public DbSet<Test> Tests => Set<Test>();
    public DbSet<TestCategory> TestCategories => Set<TestCategory>();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Test>()
            .HasKey(x => x.Id)
            .IsClustered(false);
         modelBuilder.Entity<Test>()
             .Property(x => x.ClusteringKey)
             .ValueGeneratedOnAdd()
             .UseIdentityColumn(1_000_000);
         modelBuilder.Entity<Test>()
             .HasIndex(x => x.ClusteringKey).IsUnique().IsClustered();
        modelBuilder.Entity<TestCategory>()
            .HasKey(x => new { x.TestId, x.Category })
            .IsClustered(false);
        modelBuilder.Entity<TestCategory>()
            .HasOne<Test>()
            .WithMany(x => x.Categories)
            .HasForeignKey(x => x.TestId)
            .OnDelete(DeleteBehavior.Cascade);
        modelBuilder.Entity<TestCategory>()
            .Property(x => x.ClusteringKey)
            .ValueGeneratedOnAdd()
            .UseIdentityColumn(1_000_000);
        modelBuilder.Entity<TestCategory>()
            .HasIndex(x => x.ClusteringKey).IsUnique().IsClustered(); // Works without IsUnique
        
        // SEED FOR TESTING
        var testGuid = Guid.NewGuid();
        modelBuilder.Entity<Test>()
            .HasData(new Test
            {
                Id = testGuid,
                Description = "Test",
            });
        modelBuilder.Entity<TestCategory>()
            .HasData(
            [
                new TestCategory
                {
                    Category = Category.Basic,
                    TestId = testGuid,
                },
                new TestCategory
                {
                    Category = Category.Pro,
                    TestId = testGuid,
                },
                new TestCategory
                {
                    Category = Category.SuperPro,
                    TestId = testGuid,
                }
            ]);
    }
}

Stack traces

Unhandled exception. System.InvalidOperationException: Unable to save changes because a circular dependency was detected in the data to be saved: 'TestCategory [Added] <-
Index { 'ClusteringKey' } TestCategory [Added] <-
Index { 'ClusteringKey' } TestCategory [Added]To show additional information call 'DbContextOptionsBuilder.EnableSensitiveDataLogging'.'.
   at Microsoft.EntityFrameworkCore.Utilities.Multigraph`2.ThrowCycle(List`1 cycle, Func`2 formatCycle, Func`2 formatException)
   at Microsoft.EntityFrameworkCore.Utilities.Multigraph`2.TopologicalSortCore(Boolean withBatching, Func`4 canBreakEdges, Func`2 formatCycle, Func`2 formatException)
   at Microsoft.EntityFrameworkCore.Utilities.Multigraph`2.BatchingTopologicalSort(Func`4 canBreakEdges, Func`2 formatCycle, Func`2 formatException)
   at Microsoft.EntityFrameworkCore.Update.Internal.CommandBatchPreparer.TopologicalSort(IEnumerable`1 commands)
   at Microsoft.EntityFrameworkCore.Update.Internal.CommandBatchPreparer.BatchCommands(IList`1 entries, IUpdateAdapter updateAdapter)+MoveNext()
   at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.Execute(IEnumerable`1 commandBatches, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Storage.RelationalDatabase.SaveChanges(IList`1 entries)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(IList`1 entriesToSave)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(StateManager stateManager, Boolean acceptAllChangesOnSuccess)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.<>c.<SaveChanges>b__112_0(DbContext _, ValueTuple`2 t)
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChanges()
   at Program.<Main>$(String[] args) in D:\Projekty\EFCoreCompositeKeyClustering\Program.cs:line 25

Verbose output

EF Core version

8.0.6

Database provider

Microsoft.EntityFrameworkCore.SqlServer

Target framework

.Net 8.0

Operating system

Windows 11

IDE

Rider 2024.3.4

[cincuranet]

Note for the team: Repros on 9.0.1 as well.