Efcore: OwnsMany projection exception: The given key 'EmptyProjectionMember' was not present in the dictionary

Created on 16 Aug 2020 · 4Comments · Source: dotnet/efcore

Projecting child entities that have an OwnsMany relationship with their parent causes a System.Collections.Generic.KeyNotFoundException: 'The given key 'EmptyProjectionMember' was not present in the dictionary.' in EFCore 5 Preview 7, and a System.InvalidOperationException: 'EF.Property called with wrong property name.' in EF 3.1.7.

Steps to reproduce

``` C#
public class Contact
{
public Guid Id { get; set; }
public IReadOnlyList Names { get; protected set; } = new List();
}

public class Name
{
public Guid Id { get; set; }
public Guid ContactId { get; set; }
}

public class TestDbContext : DbContext
{
public TestDbContext(DbContextOptions options) : base(options)
{

}

public DbSet<Contact> Contacts { get; set; }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Contact>().HasKey(c => c.Id);
    modelBuilder.Entity<Contact>().OwnsMany(c => c.Names, names => names.WithOwner().HasForeignKey(n => n.ContactId));
    // modelBuilder.Entity<Contact>().HasMany(c => c.Names).WithOne().HasForeignKey(n => n.ContactId); // this works

    base.OnModelCreating(modelBuilder); 
}

}


Then try projecting the collection of owned Name entities:

``` C#
var results = await context.Contacts.Select(contact => new ContactDto()
{
    Id = contact.Id,
    Names = contact.Names.Select(name => new NameDto() { }).ToArray()
}).ToListAsync();

This throws the exceptions described above in 5 Preview 7 and 3.1.7 respectively.

5 Preview 7:

System.Collections.Generic.KeyNotFoundException
  HResult=0x80131577
  Message=The given key 'EmptyProjectionMember' was not present in the dictionary.
  Source=System.Private.CoreLib
  StackTrace:
   at System.ThrowHelper.ThrowKeyNotFoundException[T](T key)
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at Microsoft.EntityFrameworkCore.Query.SqlExpressions.SelectExpression.GetMappedProjection(ProjectionMember projectionMember)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.VisitExtension(Expression extensionExpression)
   at System.Linq.Expressions.Expression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.BindProperty(EntityReferenceExpression entityReferenceExpression, IProperty property)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.TryBindMember(Expression source, MemberIdentity member)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.VisitBinary(BinaryExpression binaryExpression)
   at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerSqlTranslatingExpressionVisitor.VisitBinary(BinaryExpression binaryExpression)
   at System.Linq.Expressions.BinaryExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.TranslateInternal(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.Translate(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateExpression(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateLambdaExpression(ShapedQueryExpression shapedQueryExpression, LambdaExpression lambdaExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateWhere(ShapedQueryExpression source, LambdaExpression predicate)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.TranslateSubquery(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
   at System.Dynamic.Utils.ExpressionVisitorUtils.VisitArguments(ExpressionVisitor visitor, IArgumentProvider nodes)
   at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMemberAssignment(MemberAssignment memberAssignment)
   at System.Linq.Expressions.ExpressionVisitor.VisitMemberBinding(MemberBinding node)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMemberInit(MemberInitExpression memberInitExpression)
   at System.Linq.Expressions.MemberInitExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Translate(SelectExpression selectExpression, Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateSelect(ShapedQueryExpression source, LambdaExpression selector)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass12_0`1.<ExecuteAsync>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetAsyncEnumerator(CancellationToken cancellationToken)
   at System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1.GetAsyncEnumerator()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.<ToListAsync>d__65`1.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at EFBug.Program.<Main>d__0.MoveNext() in D:\Playground\EFBug\Program.cs:line 16

3.1.7:

System.InvalidOperationException
  HResult=0x80131509
  Message=EF.Property called with wrong property name.
  Source=Microsoft.EntityFrameworkCore.Relational
  StackTrace:
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.VisitBinary(BinaryExpression binaryExpression)
   at Microsoft.EntityFrameworkCore.SqlServer.Query.Internal.SqlServerSqlTranslatingExpressionVisitor.VisitBinary(BinaryExpression binaryExpression)
   at System.Linq.Expressions.BinaryExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.Translate(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateExpression(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateLambdaExpression(ShapedQueryExpression shapedQueryExpression, LambdaExpression lambdaExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateWhere(ShapedQueryExpression source, LambdaExpression predicate)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.TranslateSubquery(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
   at System.Dynamic.Utils.ExpressionVisitorUtils.VisitArguments(ExpressionVisitor visitor, IArgumentProvider nodes)
   at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMemberAssignment(MemberAssignment memberAssignment)
   at System.Linq.Expressions.ExpressionVisitor.VisitMemberBinding(MemberBinding node)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMemberInit(MemberInitExpression memberInitExpression)
   at System.Linq.Expressions.MemberInitExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
   at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Translate(SelectExpression selectExpression, Expression expression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateSelect(ShapedQueryExpression source, LambdaExpression selector)
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
   at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass12_0`1.<ExecuteAsync>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetAsyncEnumerator(CancellationToken cancellationToken)
   at System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1.GetAsyncEnumerator()
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.<ToListAsync>d__64`1.MoveNext()
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
   at EFBug.Program.<Main>d__0.MoveNext() in D:\Playground\EFBug3\Program.cs:line 16

  This exception was originally thrown at this call stack:
    [External Code]
    EFBug.Program.Main(string[]) in Program.cs

Changing the relationship to be HasMany instead of OwnsMany makes the code work fine.

            modelBuilder.Entity<Contact>().OwnsMany(c => c.Names, names => names.WithOwner().HasForeignKey(n => n.ContactId));
            // modelBuilder.Entity<Contact>().HasMany(c => c.Names).WithOne().HasForeignKey(n => n.ContactId); //  <-- this works

The bug is present with SqlServer provider, but not if using InMemoryDatabase.

Attached is a simple test project which reproduces the problem. EFBug.zip

This may be the same bug as reported in issue #20277

Further technical details

EF Core version: 5.0.0-preview.7.20365.15 and 3.1.7
Database provider: Microsoft.EntityFrameworkCore.SqlServer
Target framework: .NET 5.0 and .Net Core 3.0
Operating system: Windows 10
IDE: Visual Studio 2019 16.7.0 Preview 5.0

area-query customer-reported punted-for-5.0 type-bug

Source

rathga

Most helpful comment

@smitpatel Repros on latest daily

```C#
public class Contact
{
public Guid Id { get; set; }
public IReadOnlyList Names { get; protected set; } = new List();
}

public class ContactDto
{
public Guid Id { get; set; }
public IReadOnlyList Names { get; set; }
}

public class Name
{
public Guid Id { get; set; }
public Guid ContactId { get; set; }
}

public class NameDto
{
public Guid Id { get; set; }
public Guid ContactId { get; set; }
}

public class SomeDbContext : DbContext
{
private static readonly ILoggerFactory
Logger = LoggerFactory.Create(x => x.AddConsole());//.SetMinimumLevel(LogLevel.Debug));

public DbSet<Contact> Contacts { get; set; }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Contact>().HasKey(c => c.Id);
    modelBuilder.Entity<Contact>().OwnsMany(c => c.Names, names => names.WithOwner().HasForeignKey(n => n.ContactId));
    // modelBuilder.Entity<Contact>().HasMany(c => c.Names).WithOne().HasForeignKey(n => n.ContactId); // this works
}

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    => optionsBuilder
        .UseLoggerFactory(Logger)
        .EnableSensitiveDataLogging()
        .UseSqlServer(Your.SqlServerConnectionString);

}

public static class Program
{
public static async Task Main()
{
using (var context = new SomeDbContext())
{
context.Database.EnsureDeleted();
context.Database.EnsureCreated();

        var results = await context.Contacts.Select(contact => new ContactDto()
        {
            Id = contact.Id,
            Names = contact.Names.Select(name => new NameDto() { }).ToArray()
        }).ToListAsync();

    }
}

}
```

ajcvickers on 17 Aug 2020

👍2

All 4 comments

Note for triage: Try in nightly.

smitpatel on 16 Aug 2020

@smitpatel Repros on latest daily

```C#
public class Contact
{
public Guid Id { get; set; }
public IReadOnlyList Names { get; protected set; } = new List();
}

public class ContactDto
{
public Guid Id { get; set; }
public IReadOnlyList Names { get; set; }
}

public class Name
{
public Guid Id { get; set; }
public Guid ContactId { get; set; }
}

public class NameDto
{
public Guid Id { get; set; }
public Guid ContactId { get; set; }
}

public class SomeDbContext : DbContext
{
private static readonly ILoggerFactory
Logger = LoggerFactory.Create(x => x.AddConsole());//.SetMinimumLevel(LogLevel.Debug));

public DbSet<Contact> Contacts { get; set; }

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity<Contact>().HasKey(c => c.Id);
    modelBuilder.Entity<Contact>().OwnsMany(c => c.Names, names => names.WithOwner().HasForeignKey(n => n.ContactId));
    // modelBuilder.Entity<Contact>().HasMany(c => c.Names).WithOne().HasForeignKey(n => n.ContactId); // this works
}

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    => optionsBuilder
        .UseLoggerFactory(Logger)
        .EnableSensitiveDataLogging()
        .UseSqlServer(Your.SqlServerConnectionString);

}

public static class Program
{
public static async Task Main()
{
using (var context = new SomeDbContext())
{
context.Database.EnsureDeleted();
context.Database.EnsureCreated();

        var results = await context.Contacts.Select(contact => new ContactDto()
        {
            Id = contact.Id,
            Names = contact.Names.Select(name => new NameDto() { }).ToArray()
        }).ToListAsync();

    }
}

}
```

ajcvickers on 17 Aug 2020

👍2

Work-around query
C# var results = (await context.Contacts.Select(contact => new { Id = contact.Id, Names = contact.Names.Select(name => new NameDto() { }) }).ToListAsync()) .Select(e => contact = new ContactDto() { Id = contact.Id, Names = contact.Names.ToArray() )).ToList()

smitpatel on 21 Aug 2020

Thanks for the attention on this

Just a small note on the work-around.

It was not part of my bug explanation as I did not think it was relevant, but in my actual project where this bug occurs I am constructing the select expression with expression trees as the fields to be bound are selected by the user and are not known at compile time. Therefore I am projecting to ContactDto as anonymous classes (as proposed in the work-around) are not available at runtime. As such, the proposed work-around does not work for my case.

However, I gather from the work-around that the issue is something to do with to ToArray() call, so for my project changing IReadOnlyList to IEnumerable in ContactDto and dropping the ToArray() call can also work as a temporary work-around for my situation.

``` c#

public class ContactDto
{
public Guid Id { get; set; }
public IEnumerable Names { get; set; } // public IReadOnlyList Names { get; set; }
}
...
var results = await context.Contacts.Select(contact => new ContactDto()
{
Id = contact.Id,
Names = contact.Names.Select(name => new NameDto() { }) // .ToArray()
}).ToListAsync();

```

rathga on 23 Aug 2020

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