[newbie] one-to-many (parent-childeren) mapping problem

j23tom · **Joined:** Sun Dec 25, 2005 7:04 pm **Posts:** 2

NHibernate 1.0.5000.0
dbe: PostgreSQL
language: c#

Let's assume i've two classes: user and address.

In user user.hbm.xml mapping file i add below to make connection between classes
(1)

Code:

<set name="userAddresses">
            <key column="parent_id"/>
            <one-to-many class="address"/>
</set>

Now every time code reaches :

Code:

cfg.AddAssembly("myAssembly");

my app. throws NHibernate.MappingException which i do not understand:

Code:

NHibernate.MappingException: associated class not found: hydrosoft.address ---> System.TypeLoadException: Nie można załadować typu address z zestawu NHibernate, Version=1.0.1.0, Culture=neutral, PublicKeyToken=154fdcb44c4484fc.\r\n   at System.Type.GetType(String typeName, Boolean throwOnError)\r\n   at NHibernate.Util.ReflectHelper.ClassForName(String name)\r\n   at NHibernate.Cfg.Binder.ClassForFullNameChecked(String fullName, String errorMessage)\r\n   --- Koniec śladu stosu wyjątków wewnętrznych ---\r\n   at NHibernate.Cfg.Binder.ClassForFullNameChecked(String fullName, String errorMessage)\r\n   at NHibernate.Cfg.Binder.ClassForNameChecked(String name, Mappings mappings, String errorMessage)\r\n   at NHibernate.Cfg.Binder.BindOneToMany(XmlNode node, OneToMany model, Mappings mappings)\r\n   at NHibernate.Cfg.Binder.BindCollection(XmlNode node, Collection model, String className, String path, Mappings mappings)\r\n   at NHibernate.Cfg.CollectionTypeSet.Create(XmlNode node, String prefix, String path, PersistentClass owner, Mappings mappings)\r\n   at NHibernate.Cfg.Binder.PropertiesFromXML(XmlNode node, PersistentClass model, Mappings mappings)\r\n   at NHibernate.Cfg.Binder.BindRootClass(XmlNode node, RootClass model, Mappings mappings)\r\n   at NHibernate.Cfg.Binder.BindRoot(XmlDocument doc, Mappings model)\r\n   at NHibernate.Cfg.Configuration.AddValidatedDocument(XmlDocument doc)\r\n   at NHibernate.Cfg.Configuration.AddXmlReader(XmlTextReader hbmReader)\r\n   at NHibernate.Cfg.Configuration.AddInputStream(Stream xmlInputStream)\r\n   at NHibernate.Cfg.Configuration.AddAssembly(Assembly assembly, Boolean skipOrdering)\r\n   at NHibernate.Cfg.Configuration.AddAssembly(Assembly assembly)\r\n   at NHibernate.Cfg.Configuration.AddAssembly(String assemblyName)\r\n   at ... 

I don't know why it doesn't see the address class beacause i can use it (the address class) if i delete (1) code from user.hbm.xml.

Without the (1) code pass the

Code:

cfg.AddAssembly("myAssembly");

and i can add/modify/delete users and addresses easily.

Do you have any idea why it throws the exception ?

j23tom · **Joined:** Sun Dec 25, 2005 7:04 pm **Posts:** 2

it seems that instead of :

Code:

<set name="userAddresses">
            <key column="parent_id"/>
            <one-to-many class="address"/>
</set> 

it should be :

Code:

<set name="userAddresses">
            <key column="parent_id"/>
            <one-to-many class="namespace.address,myAssembly"/>
</set> 

Someone could tell me why ? In other examples i've seen class def without assembly keyword. Is there any rule for it ?

TheShark · **Joined:** Thu Aug 25, 2005 3:35 am **Posts:** 160

There is a property 'Auto-Import' defined on the mapping file, that allows you to use the class-name directly. Atleast, that works on HQL, but I guess you can use it in the mapping files as well.

sergey · **Posted:** Tue Dec 27, 2005 6:55 am

TheShark wrote:

There is a property 'Auto-Import' defined on the mapping file, that allows you to use the class-name directly. Atleast, that works on HQL, but I guess you can use it in the mapping files as well.

No, you can't. To j23tom: you have to use the assembly name because that's how reflection works in .NET. If you don't specify the name, it attempts to load the type from the currently executing assembly, which happens to be NHibernate.dll.

michal · **Posted:** Tue Dec 27, 2005 7:01 am

You can specify default assembly and namespace in the mapping

e.g.

Code:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0" assembly="myAssembly" namespace="myNamespace" >