Projection is not working for nested objects

[vvitkovsky]

Product

Hot Chocolate

Version

15

Link to minimal reproduction

https://drive.google.com/file/d/1YPaavAY69gVCTe8-06i1eGjwGmD_paog/view?usp=drive_link

Steps to reproduce

Hello,

I've got an issue, that the projection is not working for complex types. I have those models:

public class Person
{
    public string Id { get; set; } = Guid.NewGuid().ToString();

    public int Version { get; set; } = 1;

    public string FirstName { get; set; } = null!;

    public string? LastName { get; set; }

    public int Age { get; set; }    

    public Address Address { get; set; } = null!; 
}

public class Address
{
    public string ZipCode { get; set; } = null!;
}

And I am using MongoDB over Entity Framework and query with pagination, projection, sorting, and filtering:

public class Query
{
    [UsePaging]
    [UseProjection]
    [UseSorting]
    [UseFiltering]    
    public IQueryable<Person> GetPersons([Service] PersonContext aContext)
    {
        return aContext.Persons.AsQueryable();
    }
}

When I perform a simple query, it works fine:

query {
  persons {
    nodes {
      id            
    }
  }
}

But when I add a nested object, it fails:

query {
  persons {
    nodes {
      id      
      address {
        zipCode
      }
    }
  }
}

Error is this one:

{
  "errors": [
    {
      "message": "Unexpected Execution Error",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "persons"
      ],
      "extensions": {
        "message": "A tracking query is attempting to project an owned entity without a corresponding owner in its result, but owned entities cannot be tracked without their owner. Either include the owner entity in the result or make the query non-tracking using 'AsNoTracking'.",
        "stackTrace": "   at Microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.EntityMaterializerInjectingExpressionVisitor.Inject(Expression expression)\r\n   at Microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.InjectEntityMaterializers(Expression expression)\r\n   at MongoDB.EntityFrameworkCore.Query.Visitors.MongoShapedQueryCompilingExpressionVisitor.VisitShapedQuery(ShapedQueryExpression shapedQueryExpression)\r\n   at Microsoft.EntityFrameworkCore.Query.ShapedQueryCompilingExpressionVisitor.VisitExtension(Expression extensionExpression)\r\n   at MongoDB.EntityFrameworkCore.Query.MongoQueryCompilationContext.CreateQueryExecutor[TResult](Expression originalQuery)\r\n   at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass11_0`1.<ExecuteCore>b__0()\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteCore[TResult](Expression query, Boolean async, CancellationToken cancellationToken)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query, CancellationToken cancellationToken)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)\r\n   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetAsyncEnumerator(CancellationToken cancellationToken)\r\n   at System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1.GetAsyncEnumerator()\r\n   at HotChocolate.DefaultQueryableExecutable`1.ToAsyncEnumerable(CancellationToken cancellationToken)+MoveNext()\r\n   at HotChocolate.DefaultQueryableExecutable`1.ToAsyncEnumerable(CancellationToken cancellationToken)+System.Threading.Tasks.Sources.IValueTaskSource<System.Boolean>.GetResult()\r\n   at HotChocolate.Types.Pagination.QueryableCursorPagingHandler`1.QueryExecutor.QueryAsync(IQueryable`1 slicedQuery, IQueryable`1 originalQuery, Int32 offset, Boolean includeTotalCount, CancellationToken cancellationToken)\r\n   at HotChocolate.Types.Pagination.QueryableCursorPagingHandler`1.QueryExecutor.QueryAsync(IQueryable`1 slicedQuery, IQueryable`1 originalQuery, Int32 offset, Boolean includeTotalCount, CancellationToken cancellationToken)\r\n   at HotChocolate.Types.Pagination.CursorPagingHandler`2.SliceAsync(IResolverContext context, TQuery originalQuery, CursorPagingArguments arguments, CursorPaginationAlgorithm`2 algorithm, ICursorPaginationQueryExecutor`2 executor, CancellationToken cancellationToken)\r\n   at HotChocolate.Types.Pagination.QueryableCursorPagingHandler`1.SliceAsyncInternal(IResolverContext context, IQueryableExecutable`1 source, CursorPagingArguments arguments)\r\n   at HotChocolate.Types.Pagination.CursorPagingHandler.HotChocolate.Types.Pagination.IPagingHandler.SliceAsync(IResolverContext context, Object source)\r\n   at HotChocolate.Types.Pagination.PagingMiddleware.InvokeAsync(IMiddlewareContext context)\r\n   at HotChocolate.Execution.Processing.Tasks.ResolverTask.ExecuteResolverPipelineAsync(CancellationToken cancellationToken)\r\n   at HotChocolate.Execution.Processing.Tasks.ResolverTask.TryExecuteAsync(CancellationToken cancellationToken)"
      }
    }
  ],
  "data": {
    "persons": null
  }
}

I tried to modify a query like this:

aContext.Persons.AsQueryable().AsNoTracking();

But this didn't help.

Without [UseProjection], it works fine. Sample link attached.

Best regards,
Victor

What is expected?

[UseProjection] works for nested types

What is actually happening?

Projection is not working for nested types

Relevant log output

Additional context

No response

[michaelstaib]

can you share your project?

[vvitkovsky]

I have attached a link to a zip file with a sample