c# – 如何在linq-to-Nhibernate中使用多个条件的连接

发布时间：2020-12-15 04:10:54 所属栏目：百科来源：网络整理

导读：我有两个课程(请求和请求细节).我需要一个 Linq到NHibernatequery之间的两个类之间加入. var q = SessionInstance.QueryRequest() .Where(x = x.State == "Init");var q2 = SessionInstance.QueryRequestDetail();q2 = q2.Where(xx = xx.Purpose.Contains("P

我有两个课程(请求和请求细节).我需要一个 Linq到NHibernatequery之间的两个类之间加入.

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();

当我向q2添加Where条件时,Result有一个运行时错误.异常消息是：不支持指定的方法.

堆栈跟踪：

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,ISessionFactoryImplementor factory)
   at NHibernate.Engine.Query.QueryPlanCache.GetHQLQueryPlan(IQueryExpression queryExpression,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)

为什么？

解决方法

这可能是一个bug.

以下是您的问题的解决方法：

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();

（编辑：李大同）

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