InMemory: Decompose join condition which uses equals for comparison

[paulovila]

Microsoft.EntityFrameworkCore.InMemory 5.0.0 can't inner join Enums

Given a model with entity A with a property Id as primary key, where Id is an enum PEnum, and another entity B with a foreign key to A through a property called AId, and a projection entity AB
The following query inner joining A and B runs successfully with SQL server provider:

var r = await (from a in _context.As
                      join b in _context.Bs on a.Id equals b.AId
                     select new AB{ AId = a.Id, Name = b.Name })
        .ToArrayAsync();

however, Microsoft.EntityFrameworkCore.InMemory thows and exception described below.

Expected behaviour

The query should not fail in Microsoft.EntityFrameworkCore.InMemory 5.0.0 because enums should be transparently using its inner type (int in this case), as SQLServer provider 5.0 does, and InMemory used to do in 3.1

Stack Trace

System.InvalidOperationException: The LINQ expression 'DbSet<StatusMapEvent>()
    .Join(
        inner: DbSet<StatusMap>(), 
        outerKeySelector: s => s.StatusMapId, 
        innerKeySelector: s0 => s0.Id, 
        resultSelector: (s, s0) => new TransparentIdentifier<StatusMapEvent, StatusMap>(
            Outer = s, 
            Inner = s0
        ))' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'. See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.
    at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.<VisitMethodCall>g__CheckTranslated|15_0(ShapedQueryExpression translated, <>c__DisplayClass15_0& )
   at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at Microsoft.EntityFrameworkCore.InMemory.Query.Internal.InMemoryQueryableMethodTranslatingExpressionVisitor.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.InMemory.Query.Internal.InMemoryQueryableMethodTranslatingExpressionVisitor.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.InMemory.Query.Internal.InMemoryQueryableMethodTranslatingExpressionVisitor.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.InMemory.Query.Internal.InMemoryQueryableMethodTranslatingExpressionVisitor.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.InMemory.Query.Internal.InMemoryQueryableMethodTranslatingExpressionVisitor.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[TSource](IQueryable`1 source, CancellationToken cancellationToken)
   at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToArrayAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
   at ALP.AMS.Repository.UnitTests.StatusMapRepositoryUnitTests.ShouldGetStatusMap() in C:\Repos\ALP-AMSServer\src\ALP.AMS.Repository.UnitTests\StatusMapRepositoryUnitTests.cs:line 28
   at Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.ThreadOperations.ExecuteWithAbortSafety(Action action)

Include provider and version information

EF Core version: 5.0
Database provider: Microsoft.EntityFrameworkCore.InMemory
Target framework: ( .NET 5.0)

[smitpatel]

This issue is lacking enough information for us to effectively reproduce. Please post a runnable project/solution or complete code listing that demonstrates the behavior you are seeing.

[paulovila]

Please checkout the failing test GetShouldNotFailTest : https://github.com/paulovila/EnumsInMemory (now public)