EF Core 3.1 过滤的通用表达式在 .Any(...) 上引发异常

Question

I try to create a generic way of getting data via EF Core 3.1 with the same filtering of different children. For this, I try to extract the searched expression inside of Any(...).

public Expression<Func<PraeparatUpdateEntity, bool>> IsToApprovePackungUpdates_Working()
{
   return entity => entity.PackungUpdates.Any(e => !e.IsImported
      && e.UpdateState != EntityUpdateState.Accepted
      && e.UpdateType != EntityUpdateType.Unchanged);
}

public Expression<Func<PraeparatUpdateEntity, bool>> IsToApprovePackungUpdates_NotWorking()
{
   var func = new Func<PackungUpdateEntity, bool>(e => !e.IsImported
      && e.UpdateState != EntityUpdateState.Accepted
      && e.UpdateType != EntityUpdateType.Unchanged);

   return entity => entity.PackungUpdates.Any(func);
}

public new async Task<ICollection<PraeparatUpdateEntity>> GetToApproveAsync(bool trackChanges = false)
{ 
   var query = Set.Include(praeparatUpdateEntity => praeparatUpdateEntity.PackungUpdates)
      .Where(IsToApprovePackungUpdates_NotWorking());
            
   if (!trackChanges)
   {
      query = query.AsNoTracking();
   }

   return await query.ToListAsync();
}

The first version is working. The second one fails with errormessage:

System.ArgumentException : Expression of type 'System.Func`2[MyProject.Data.Common.Entities.Update.PackungUpdateEntity,System.Boolean]' cannot be used for parameter of type 'System.Linq.Expressions.Expression`1[System.Func`2[MyProject.Data.Common.Entities.Update.PackungUpdateEntity,System.Boolean]]' of method 'Boolean Any[PackungUpdateEntity](System.Linq.IQueryable`1[MyProject.Data.Common.Entities.Update.PackungUpdateEntity], System.Linq.Expressions.Expression`1[System.Func`2[MyProject.Data.Common.Entities.Update.PackungUpdateEntity,System.Boolean]])' (Parameter 'arg1')
   at System.Dynamic.Utils.ExpressionUtils.ValidateOneArgument(MethodBase method, ExpressionType nodeKind, Expression arguments, ParameterInfo pi, String methodParamName, String argumentParamName, Int32 index)
   at System.Linq.Expressions.Expression.Call(Expression instance, MethodInfo method, Expression arg0, Expression arg1)
   at System.Linq.Expressions.Expression.Call(Expression instance, MethodInfo method, IEnumerable`1 arguments)
   at Microsoft.EntityFrameworkCore.Query.Internal.EnumerableToQueryableMethodConvertingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
   at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at System.Linq.Expressions.ExpressionVisitor.VisitLambda[T](Expression`1 node)
   at System.Linq.Expressions.Expression`1.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   at System.Linq.Expressions.ExpressionVisitor.VisitUnary(UnaryExpression node)
   at System.Linq.Expressions.UnaryExpression.Accept(ExpressionVisitor visitor)
   at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
   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.QueryTranslationPreprocessor.Process(Expression query)
   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[TSource](IQueryable`1 source, CancellationToken cancellationToken)
   at MyProject.Data.Repositories.PraeparatUpdateRepository.GetToApproveAsync(Boolean trackChanges) in C:\git\MyProject\Source\MyProject.Data\Repositories\PraeparatUpdateRepository.cs:line 156
   at MyProject.Data.Tests.Integration.RepositoryNavigationPropertyLoadingTests.GetAllPraeparatUpdates_WhereToApprove_WithNavigationProperties_OK_Test() in C:\git\MyProject\Source\MyProject.Data.Tests.Integration\RepositoryNavigationPropertyLoadingTests.cs:line 328
--- End of stack trace from previous location where exception was thrown ---

******** UPDATE ********

If I add AsQueryable() to my IEnumerable database children I can add my Expressions like that:

var query = Set.Include(praeparatUpdateEntity => praeparatUpdateEntity.PackungUpdates)
   .Include(praeparatUpdateEntity => praeparatUpdateEntity.SequenzUpdates)
   .ThenInclude(sequenzUpdateEntity => sequenzUpdateEntity.ApplikationsartUpdates)
   .Include(praeparatUpdateEntity => praeparatUpdateEntity.SequenzUpdates)
   .ThenInclude(sequenzUpdateEntity => sequenzUpdateEntity.DeklarationUpdates)
   .Where(IsToApprove<PraeparatUpdateEntity>()
      .OrElse(entity => entity.PackungUpdates.AsQueryable().Any(IsToApprove<PackungUpdateEntity>()))
      .OrElse(entity => entity.SequenzUpdates.AsQueryable().Any(IsToApprove<SequenzUpdateEntity>()))
      .OrElse(entity => entity.SequenzUpdates.SelectMany(sequenzUpdateEntity => sequenzUpdateEntity.ApplikationsartUpdates).AsQueryable()
         .Any(IsToApprove<ApplikationsartUpdateEntity>()))
      .OrElse(entity => entity.SequenzUpdates.SelectMany(sequenzUpdateEntity => sequenzUpdateEntity.DeklarationUpdates).AsQueryable()
         .Any(IsToApprove<DeklarationUpdateEntity>())));

and my generic Expression:

public Expression<Func<T, bool>> IsToApprove<T>() where T : class, IUpdateEntity
{
   return entity => !entity.IsImported && entity.UpdateState != EntityUpdateState.Accepted
   && entity.UpdateType != EntityUpdateType.Unchanged;
}

which seems at the moment to work... Tests in progress

Answer 1

Entity Framework is build on top of IQueryable which is using expression trees . Those are required to analyze your code at runtime and transform it to SQL. In first snippet compiler takes all the heavy lifting of building expression trees for you. You can try building expression tree yourself, but usually it is not that simple task. In this case you can try something like this:

Expression<Func<PackungUpdateEntity, bool>> exp = e => !e.IsImported
      && e.UpdateState != EntityUpdateState.Accepted
      && e.UpdateType != EntityUpdateType.Unchanged;

var any = typeof(Enumerable)
    .GetMethods()
    .Where(mi => mi.Name == nameof(Enumerable.Any) && mi.GetParameters().Length == 2)
    .Single()
    .MakeGenericMethod(typeof(PackungUpdateEntity));
var param = Expression.Parameter(typeof(PraeparatUpdateEntity));
var toAny = Expression.PropertyOrField(param, nameof(PraeparatUpdateEntity.PackungUpdates));
var call = Expression.Call(any, toAny, exp); 
var result = Expression.Lambda<Func<PraeparatUpdateEntity, bool>>(call, param);

return result;