如何使用linq-to-Nhibernate中的多個條件加入

我有兩個類（Request & RequestDetail）。我需要通過連接在兩個類之間查詢Linq To NHibernate。如何使用linq-to-Nhibernate中的多個條件加入

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();

當我加入Where條件q2，結果有一個運行時錯誤。例外的消息是：Specified method is not supported.

堆棧跟蹤：

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)

爲什麼？

來源

2012-11-15 Ehsan

這可能是一個錯誤。

這裏是你的問題的解決方法：

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();

來源

2012-11-16 05:33:30 SHSE

這個答案必須向全世界宣佈！這是它的方式，它的工作方式！我無法相信我們看過多少次，沒有找到任何解決方案，除了可怕的QueryOver的東西，或被迫創建新的映射！ – user2415376

用流利的表示法：

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();

來源

2017-01-03 12:56:40

如何使用linq-to-Nhibernate中的多個條件加入

回答

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