NHibernate LINQ queries with nested .Any() conditions - linq

Question

Here are what my classes look like:
class User
{
IList<UserRedemptionCode> UserRedemptions;
}
class UserRedemptionCode
{
string Code;
}
class Course
{
IList<CourseRedemptionCode> CourseRedemptions;
}
class CourseRedemptionCode
{
string Code;
string SomeData;
}
I want to retrieve all of the courses that match a redemption code that is associated with a user. Here is the current IQuerable call I am making:
IQueryable<Course> query = Courses.Where(
course => course.CourseRedemptions.Any(
cr => user.UserRedemptions.Any(rc => cr.Code == rc.Code));
However, this doesn't seem to work with NHibernate. I get this exception:
System.NotSupportedExceptionSpecified method is not supported.
at NHibernate.Hql.Ast.ANTLR.PolymorphicQuerySourceDetector.GetClassName(IASTNode querySource)
at NHibernate.Hql.Ast.ANTLR.PolymorphicQuerySourceDetector.Process(IASTNode tree)
at NHibernate.Hql.Ast.ANTLR.AstPolymorphicProcessor.Process()
at NHibernate.Hql.Ast.ANTLR.ASTQueryTranslatorFactory.CreateQueryTranslators(IASTNode ast, String queryIdentifier, String collectionRole, Boolean shallow, IDictionary`2 filters, ISessionFactoryImplementor factory)
at NHibernate.Hql.Ast.ANTLR.ASTQueryTranslatorFactory.CreateQueryTranslators(String queryIdentifier, IQueryExpression queryExpression, String collectionRole, Boolean shallow, IDictionary`2 filters, ISessionFactoryImplementor factory)
at NHibernate.Engine.Query.QueryPlanCache.GetHQLQueryPlan(IQueryExpression queryExpression, Boolean shallow, IDictionary`2 enabledFilters)
at NHibernate.Impl.AbstractSessionImpl.GetHQLQueryPlan(IQueryExpression queryExpression, Boolean shallow)
at NHibernate.Impl.AbstractSessionImpl.CreateQuery(IQueryExpression queryExpression)
at NHibernate.Linq.DefaultQueryProvider.PrepareQuery(Expression expression, IQuery& query, NhLinqExpression& nhQuery)
at NHibernate.Linq.DefaultQueryProvider.Execute(Expression expression)
at NHibernate.Linq.DefaultQueryProvider.Execute[TResult](Expression expression)
at Remotion.Linq.QueryableBase`1.GetEnumerator()
at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
at System.Web.Http.Filters.EnumerableEvaluatorFilter.Convert[T](Object input)
at System.Web.Http.Filters.EnumerableEvaluatorFilter.OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
at System.Web.Http.Filters.ActionFilterAttribute.CallOnActionExecuted(HttpActionContext actionContext, HttpResponseMessage response, Exception exception)
at System.Web.Http.Filters.ActionFilterAttribute.<>c__DisplayClass4.<System.Web.Http.Filters.IActionFilter.ExecuteActionFilterAsync>b__2(HttpResponseMessage response)
at System.Threading.Tasks.TaskHelpersExtensions.<>c__DisplayClass2e`2.<Then>b__2d(Task`1 t)
at System.Threading.Tasks.TaskHelpersExtensions.ThenImpl[TTask,TOuterResult](TTask task, Func`2 continuation, CancellationToken cancellationToken)
There is also another issue, in this query I get back a list of courses, but I also need the CourseRedemptionCode associated with the user so I can get SomeData.
Any ideas? Is there another way to do this query?

Answer 1

There are several issues in NHibernate Jira matching "PolymorphicQuerySourceDetector" or "Any", some recently fixed, but you don't state which NHibernate version you are using.
As alternative, and probably better anyway, try something along these lines:
var codes = user.UserRedemptions.Select(ur => ur.Code).ToList();
var query = (from c in Courses
from cr in c.CourseRedemptions
where codes.Contains(cr.Code)
select new { c, cr });
Note that if multiple codes match, you will get the same course multiple times in the response. You could also remove "cr" from the select statement, and look for the matching code in memory afterwards.

Answer 2

Before you try Oskar's answer, try this because, depending on the mapping it may work in SQL:
Example - replace:
.Where(u => u.Businesses.Any(ub => trainee.Businesses.Any(tb => tb.Id == ub.Id)))
with
.Where(u => u.Businesses.Any(ub => trainee.Businesses.Contains(ub)))
I just tried this and it worked for me. YMMV!
If it does it should be preferred as it could create a more terse SQL statement and pull back less data.