AsQueryable() on navigation property

[ErazerBrecht]

Steps to reproduce

Use AsQueryable() on navigation property

Probably I'm doing something incorrect. Thanks in advance for reading this.

The issue

I need to check the same specific condition (where clause) many times.
I this condition changes I don't want to change all my queries. So I wanted to abstract this condition in a separate method.

return _ctx.Projects.Where(p => p.CompanyId == companyId &&
                          (p.Type == Enums.ProjectType.Open || 
                           p.Invites.Any(i => i.InviteeId == userId))).ToList()

Changed it with a extension method (on IQueryable) to:

return _ctx.Projects.Where(p => p.CompanyId == companyId)
                    .IsVisibleForResearcher(userId).ToList()

Everything working fine (generates the same SQL query). Now I also need this where projects is a navigation property:

Imagine that a company has projects. And I only want to retrieve the companies where the user can at least see one project.

return _ctx.Companies
       .Where(c => c.Projects.AsQueryable().IsVisibleForCompanyAccount(userId).Any())

After searching a while I learnt about Expression<Func<Project, bool>>

return _ctx.Companies
            .Where(c => c.Projects.AsQueryable().Any(IsProjectVisibleForResearcher(userId)))

This however resulted in the same exception.

Extra details:

Extension method:

public static IEnumerable<Project> IsVisibleForResearcher(this ICollection<Project> projects, string userId)
{
    return projects.Where(p => p.Type == Enums.ProjectType.Open || p.Invites.Any(i => i.InviteeId == userId));
}

Expression method:

public Expression<Func<Project, bool>> IsProjectVisibleForResearcher(string userId)
{
    return p => p.Type == Enums.ProjectType.Open || p.Invites.Any(i => i.InviteeId == userId);
}

Exception

Exception message: Could not parse expression 'c.Projects.AsQueryable()': This overload of the method 'System.Linq.Queryable.AsQueryable' is currently not supported.

Stack trace:
   at Remotion.Linq.Parsing.Structure.MethodCallExpressionParser.GetNodeType(MethodCallExpression expressionToParse)
   at Remotion.Linq.Parsing.Structure.MethodCallExpressionParser.Parse(String associatedIdentifier, IExpressionNode source, IEnumerable`1 arguments, MethodCallExpression expressionToParse)
   at Remotion.Linq.Parsing.Structure.ExpressionTreeParser.ParseMethodCallExpression(MethodCallExpression methodCallExpression, String associatedIdentifier)
   at Remotion.Linq.Parsing.Structure.ExpressionTreeParser.ParseMethodCallExpression(MethodCallExpression methodCallExpression, String associatedIdentifier)
   at Remotion.Linq.Parsing.Structure.QueryParser.GetParsedQuery(Expression expressionTreeRoot)
   at Remotion.Linq.Parsing.ExpressionVisitors.SubQueryFindingExpressionVisitor.Visit(Expression expression)
   at System.Linq.Expressions.ExpressionVisitor.VisitLambda[T](Expression`1 node)
   at System.Linq.Expressions.Expression`1.Accept(ExpressionVisitor visitor)
   at Remotion.Linq.Parsing.ExpressionVisitors.SubQueryFindingExpressionVisitor.Visit(Expression expression)
   at System.Linq.Enumerable.SelectListPartitionIterator`2.ToArray()
   at System.Linq.Enumerable.ToArray[TSource](IEnumerable`1 source)
   at Remotion.Linq.Parsing.Structure.MethodCallExpressionParser.Parse(String associatedIdentifier, IExpressionNode source, IEnumerable`1 arguments, MethodCallExpression expressionToParse)
   at Remotion.Linq.Parsing.Structure.ExpressionTreeParser.ParseMethodCallExpression(MethodCallExpression methodCallExpression, String associatedIdentifier)
   at Remotion.Linq.Parsing.Structure.ExpressionTreeParser.ParseMethodCallExpression(MethodCallExpression methodCallExpression, String associatedIdentifier)
   at Remotion.Linq.Parsing.Structure.QueryParser.GetParsedQuery(Expression expressionTreeRoot)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass19_0`1.<CompileQuery>b__0()
   at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
   at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)
   at Remotion.Linq.QueryableBase`1.GetEnumerator()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at DAL.Repositories.CompanyRepository.GetAllAllowedCompanies(String userId) in E:\DAL\Repositories\CompanyRepository.cs:line 39
   at BLL.Managers.CompanyManager.GetAllAlowedCompanies(ClaimsPrincipal user) in E:\src\BLL\Managers\CompanyManager.cs:line 44
   at API.Controllers.CompanyController.GetAllCompanies() in E:\src\API\Controllers\CompanyController.cs:line 44
   at lambda_method(Closure , Object , Object[] )
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionFilterAsync>d__28.MoveNext()

Further technical details

EF Core version: (found in project.json or packages.config)
Operating system: Windows 10 Pro
Visual Studio version: Visual Studio 15 Professional

Other details about my project setup:
ASP.NET Core
.NET Core 1.0.1

[ErazerBrecht]

Because of this http://stackoverflow.com/a/40328769/2961887. I learnt to use LinqKit.

This did resolve my issue. You can close this issue.

[smitpatel]

dupe of #6132
This is an issue with Re-Linq query parser

[zhenlei520]

Because of this http://stackoverflow.com/a/40328769/2961887， i solved my problem，Thank you very much