系列抽象类和NHibernate
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【中文标题】系列抽象类和NHibernate【英文标题】：Series of abstract classes and NHibernate 【发布时间】：2010-05-08 20:57:24 【问题描述】：首先感谢您抽出宝贵时间查看此内容。
对于我正在进行的一个研究项目，我有一个有点复杂的设计（我已经得到了）通过 NHibernate 持久化到数据库。
这是类层次结构的示例：
alt text http://img215.imageshack.us/img215/3998/transit.png
TransitStrategy、TransportationCompany 和 TransportationLocation 都是抽象类。
我目前的 XML 配置是：
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="Vacationizer"
namespace="Vacationizer.Domain.Transit">
<class name="TransitStrategy">
<id name="TransitStrategyId">
<generator class="guid" />
</id>
<property name="Restrictions" />
<joined-subclass name="Flight" table="Flight_TransitStrategy">
<key column="TransitStrategyId" />
<property name="DepartingAirport" />
<property name="ArrivingAirport" />
<property name="Airline" />
<property name="FlightNumber" />
<property name="FlightArrivalTime" />
<property name="FlightDepartureTime" />
</joined-subclass>
<joined-subclass name="RentalCar" table="RentalCar_TransitStrategy">
<key column="TransitStrategyId" />
<property name="RentalCarBranch" />
<property name="CarMake" />
<property name="CarModel" />
<property name="CarYear" />
<property name="CarColor" />
<property name="RentalBegins" />
<property name="RentalEnds" />
</joined-subclass>
</class>
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="Vacationizer"
namespace="Vacationizer.Domain.Transit">
<class name="TransportationCompany">
<id name="TransportationCompanyId">
<generator class="guid" />
</id>
<property name="Name" />
<property name="Reviews" />
<property name="Website" />
<property name="Photo" />
<joined-subclass name="Airline" table="Airline_TransportationCompany">
<key column="TransportationLocationId" />
</joined-subclass>
<joined-subclass name="RentalCarAgency" table="RentalCarAgency_TransportationCompany">
<key column="TransportationLocationId" />
</joined-subclass>
</class>
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
assembly="Vacationizer"
namespace="Vacationizer.Domain.Transit">
<class name="TransportationLocation">
<id name="TransportationLocationId">
<generator class="guid" />
</id>
<property name="Name" />
<property name="Image" />
<property name="Geolocation" />
<property name="Reviews" />
<!-- <property name="HoursOpen" />-->
<property name="PhoneNumber" />
<property name="FaxNumber" />
<joined-subclass name="Airport" table="Airport_TransportationLocation">
<key column="TransportationLocationId" />
<property name="AirportCode" />
<property name="Website" />
</joined-subclass>
<joined-subclass name="RentalCarBranch" table="RentalCarBranch_TransportationLocation">
<key column="TransitStrategyId" />
<property name="Agency" />
</joined-subclass>
</class>
但是，每当我尝试使用此架构时，我都会收到此错误/堆栈跟踪：
------ Test started: Assembly: Vacationizer.Tests.dll ------
TestCase 'M:Vacationizer.Tests.VacationRepository_Fixture.TestFixtureSetUp'
failed: Could not compile the mapping document: Vacationizer.Mappings.TransitStrategy.hbm.xml
NHibernate.MappingException: Could not compile the mapping document: Vacationizer.Mappings.TransitStrategy.hbm.xml ---> NHibernate.MappingException: Problem trying to set property type by reflection ---> NHibernate.MappingException: class Vacationizer.Domain.Transit.RentalCar, Vacationizer, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null not found while looking for property: RentalCarBranch ---> NHibernate.PropertyNotFoundException: Could not find a getter for property 'RentalCarBranch' in class 'Vacationizer.Domain.Transit.RentalCar'
at NHibernate.Properties.BasicPropertyAccessor.GetGetter(Type type, String propertyName)
at NHibernate.Util.ReflectHelper.ReflectedPropertyClass(String className, String name, String accessorName)
--- End of inner exception stack trace ---
at NHibernate.Util.ReflectHelper.ReflectedPropertyClass(String className, String name, String accessorName)
at NHibernate.Mapping.SimpleValue.SetTypeUsingReflection(String className, String propertyName, String accesorName)
--- End of inner exception stack trace ---
at NHibernate.Mapping.SimpleValue.SetTypeUsingReflection(String className, String propertyName, String accesorName)
at NHibernate.Cfg.XmlHbmBinding.ClassBinder.CreateProperty(IValue value, String propertyName, String className, XmlNode subnode, IDictionary`2 inheritedMetas)
at NHibernate.Cfg.XmlHbmBinding.ClassBinder.PropertiesFromXML(XmlNode node, PersistentClass model, IDictionary`2 inheritedMetas, UniqueKey uniqueKey, Boolean mutable, Boolean nullable, Boolean naturalId)
at NHibernate.Cfg.XmlHbmBinding.JoinedSubclassBinder.HandleJoinedSubclass(PersistentClass model, XmlNode subnode, IDictionary`2 inheritedMetas)
at NHibernate.Cfg.XmlHbmBinding.ClassBinder.PropertiesFromXML(XmlNode node, PersistentClass model, IDictionary`2 inheritedMetas, UniqueKey uniqueKey, Boolean mutable, Boolean nullable, Boolean naturalId)
at NHibernate.Cfg.XmlHbmBinding.RootClassBinder.Bind(XmlNode node, HbmClass classSchema, IDictionary`2 inheritedMetas)
at NHibernate.Cfg.XmlHbmBinding.MappingRootBinder.AddRootClasses(XmlNode parentNode, IDictionary`2 inheritedMetas)
at NHibernate.Cfg.XmlHbmBinding.MappingRootBinder.Bind(XmlNode node)
at NHibernate.Cfg.Configuration.AddValidatedDocument(NamedXmlDocument doc)
--- End of inner exception stack trace ---
at NHibernate.Cfg.Configuration.LogAndThrow(Exception exception)
at NHibernate.Cfg.Configuration.AddValidatedDocument(NamedXmlDocument doc)
at NHibernate.Cfg.Configuration.ProcessMappingsQueue()
at NHibernate.Cfg.Configuration.AddDocumentThroughQueue(NamedXmlDocument document)
at NHibernate.Cfg.Configuration.AddXmlReader(XmlReader hbmReader, String name)
at NHibernate.Cfg.Configuration.AddInputStream(Stream xmlInputStream, String name)
at NHibernate.Cfg.Configuration.AddResource(String path, Assembly assembly)
at NHibernate.Cfg.Configuration.AddAssembly(Assembly assembly)
at NHibernate.Cfg.Configuration.AddAssembly(String assemblyName)
at NHibernate.Cfg.Configuration.DoConfigure(IHibernateConfiguration hc)
at NHibernate.Cfg.Configuration.Configure()
VacationRepository_Fixture.cs(24,0): at Vacationizer.Tests.VacationRepository_Fixture.TestFixtureSetUp()
0 passed, 1 failed, 0 skipped, took 8.38 seconds (Ad hoc).
关于如何以不同方式实现此功能的任何想法？非常感谢！
【问题讨论】：
【参考方案1】：错误本身很清楚：RentalCar 的映射定义了一个可能未声明的 RentalCarBranch 属性（检查拼写错误；我个人将属性命名为 Branch）。
还有另一个错误：您将所有内容定义为<property>，而所有持久实体引用都应声明为<many-to-one>。
【讨论】：
迭戈，非常感谢您的意见，但这是我在复制问题时的错误。您绝对正确，因为您的解决方案可以解决它，但我相信另一个问题正在发挥作用。截至早上 7 点，我才开始工作，但还有很多复杂的事情阻碍了我。如果它通过了我的单元测试套件，我将在稍后发布我的修复。再次感谢您的帮助！【参考方案2】：根据我在异常中看到的情况，这表明您的 RentalCar 类没有声明 RentalCarBranch 属性。
是这样吗？
【讨论】：
尼尔，请参阅我对 Diego 的上述评论。非常感谢！以上是关于系列抽象类和NHibernate的主要内容，如果未能解决你的问题，请参考以下文章