所有删除孤儿为Nhibernate

Question

所以我有一个父对象称为顺序和子级对象集合称为orderLineItems Cascade设置为在nHibernate中的所有删除孤儿。这是我的代码。

using(var session = _sessionManager.GetSession()) 
     using (var transaction = session.BeginTransaction()) 
     { 

      var order = _repository.GetOrderEagerlyByOrderId(session, fromDb.Id); 
      var now = DateTime.Now; 
      const string user = "GNB\\Username"; 
      var future = now.AddYears(1); 
      var taxType = new TaxType(0, "Code", "AlternateNameE", "AlternateNameF", "NameE", "NameF", "DescriptionE", "DescriptionF", 13, now, future, user, now, user, now); 
      var _serviceCatRep = new ServiceCatalogueRepository(); 

      var serviceCatalogueItem = _serviceCatRep.GetServiceCatalogueItemByCode(session, "VR-PASS"); 
      var orderLineItem1 = new OrderLineItem(0, null, "DescriptionE", "DescriptionF", 1, 10, null, null, 5, false, serviceCatalogueItem, null, user, now, user, future); 

      order.OrderLineItems.Clear(); 

      order.OrderLineItems = order.OrderLineItems == null ? new List<IOrderLineItem> { orderLineItem1 } : new List<IOrderLineItem>(order.OrderLineItems) { orderLineItem1 }; 

      _repository.SaveOrUpdate(session, order); 
      transaction.Commit(); 
     } 

它无法在transaction.Commit();出现错误：

NHibernate.HibernateException : A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance

此外，什么都之间的差异全删除，孤儿用一个例子。

Answer 1

你已经有了：

order.OrderLineItems.Clear(); 

order.OrderLineItems = order.OrderLineItems == null 
    ? new List<IOrderLineItem> { orderLineItem1 } 
    : new List<IOrderLineItem>(order.OrderLineItems) { orderLineItem1 }; 

首先，如果order.OrderLineItems为null，则order.OrderLineItems.Clear（）会抛出一个NullReferenceException，其次是问题的出现，因为你正在分配一个新的List来订购.OrderLineItems，所以NHibernate不知道该如何级联删除。为了得到它的工作，只是改变了下联：

order.OrderLineItems.Add(orderLineItem1); 

Answer 2

在您的映射 - 标记）的集合作为逆（

HasMany(x=>x.OrderLineItems) 
    .Inverse();