Wie Join mit mehreren Bedingungen in Linq-zu-Nhibernate verwenden

Question

Ich habe zwei Klassen (Request & RequestDetail). Ich brauche eine Linq To NHibernate Abfrage zwischen zwei Klassen von Join.

var q = SessionInstance.Query<Request>() 
     .Where(x => x.State == "Init"); 

var q2 = SessionInstance.Query<RequestDetail>(); 
q2 = q2.Where(xx => xx.Purpose.Contains("Purpose Sample")); // This line has a error When execution ‍‍`q.ToList()‍` 

q = q.Join(q2, request => request.Id, detail => detail.Id, (request, detail) => request); 

return q.ToList(); 

Wenn ich einen Where Zustand zu q2 hinzugefügt, hat Ergebnis einen Laufzeitfehler. Nachricht von Ausnahme ist: Specified method is not supported.

Stack Trace:

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.NhQueryProvider.PrepareQuery(Expression expression, IQuery& query, NhLinqExpression& nhQuery) 
    at NHibernate.Linq.NhQueryProvider.Execute[TResult](Expression expression) 
    at Remotion.Data.Linq.QueryableBase`1.GetEnumerator() 
    at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection) 
    at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source) 

Warum?

Answer 1

Es könnte ein Fehler sein.

Hier ist Abhilfe für das Problem:

var q = (from request in session.Query<Request>() 
     join detail in session.Query<RequestDetail>() on request.Id equals detail.Id 
     where request.State == "Init" && detail.Purpose.Contains("Purpose Sample") 
     select request).ToList(); 

Answer 2

In fließend-Notation:

var q = session.Query<Request>() 
     .Join(session.Query<RequestDetail>(), request => request.Id, detail => detail.Id, (request, detail) => new { 
      r = request, 
      d = detail 
     }) 
     .Where(rd => rd.r.State == "Init" && rd.d.Purpose.Contains("Purpose Sample")) 
     .Select(rd => rd.r) 
     .ToList();