Adding one-to-many and getting unmapped class

jfputnam2 · **Posted:** Tue Dec 22, 2009 1:53 pm

Having trouble using one-to-many association. I think someone should put up a check list of what you need for each type of association. The examples always show one way to do things and it is always using features I don't care to.

What I have are two tables. An associate table and a user_permissions table.

I am using VB and VS2008 and nhibernate 2.1.0.4000

I have the two tables set up with the approriate .hbm.xml files set as embedded resources. With the association removed I can run the program and do a query and print out the values of both tables, ergo the tables are getting mapped and used fine.

But when I add in an association and run the same program, The program gets an exception when it tries to access the DB_User_Permissions in a query that works when the association is not there, and I get the:

'Association references unmapped class: DB_User_Permissions' message saying that added association is not connecting to the existing class. The association I added is

Code:

  <set name="User_Permissions" lazy="false">
    <key  column ="User_ID"/>
    <one-to-many class="DB_User_Permissions"/>
  </set>

There is a forgien key defined in User_Permssions assoicating the User_ID with User_Id in Association

The .hbm. files are

Code:

<?xml version="1.0"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true">
<class name="<assembly>.DBWrappers.DB_Associate, <assembly>" lazy="false" table="Associate"> 
 
    <id name="User_ID" type="integer" column="User_ID">
       <generator class="native" />
    </id>
    <property name="User_Name" type="string" column="User_Name"/>
    <property name="Last_Name" type="string" column="Last_Name"/>
    <property name="First_Name" type="string" column="First_Name"/>
    <property name="Phone_Number" type="string" column="Phone_Number"/>
    <property name="Group_ID" type="integer" column="Group_ID"/>
    <property name="Supervisor_ID" type="integer" column="Supervisor_ID"/>
    <property name="Email" type="string" column="Email"/>
    <property name="External_Only" type="string" column="External_Only"/>
    <property name="Has_External" type="string" column="Has_External"/>
  <set name="User_Permissions" lazy="true">
    <key  column ="User_ID"/>
    <one-to-many class="DB_User_Permissions"/>
  </set>
</class> 
</hibernate-mapping> 

and

Code:

<?xml version="1.0"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true">
<class name="<assembly.DBWrappers.DB_User_Permissions, <assembly" lazy="false" table="User_Permissions"> 
 
    <id name="User_Id" type="integer" column="User_Id">
       <generator class="native" />
    </id>
    <property name="Permission_Id" type="integer" column="Permission_Id"/>
    <property name="Crt_Date" type="string" column="Crt_Date"/>
    <property name="Who_Crt" type="string" column="Who_Crt"/>
    <property name="Permission_Disabled" type="String" column="Permission_Disabled"/>
    <many-to-one name="User" column="User_Id"/>

</class> 
</hibernate-mapping> 

And some code in the DB_Associates table (I add DB_ to the table name for the class)
that was uncommented out along with including the <set in the .hbm. to generated this error

Code:

        Private _User_Permissions As IList

...

        '------------------------------------------------------------------------------------------------
        '---------Get/Set for virtual list of permissions: List of ser_Permissions 
        '------------------------------------------------------------------------------------------------

        Public Property User_Permissions() As IList

            Get
                Return _User_Permissions
            End Get
            Set(ByVal Value As IList)
                _User_Permissions = Value
            End Set
        End Property

Anyone have a clue what is wrong here?

Thanks

---John Putnam

jfputnam2 · **Posted:** Tue Dec 22, 2009 5:17 pm

I worked around the problem. the

Code:

  <set name="User_Permissions" lazy="false">
    <key  column ="User_ID"/>
    <one-to-many class="<assemblyname>.DBWrappers.DB_User_Permissions, <assemblyname>"/>
  </set>
 

<actual assembly name replaced above>

needed the assembly name.namespace.class, assembly in the class parameter. that and importing Iesi.Collections in a few places. But I got the mapping to finally work.

---John Putnam

wolli · **Posted:** Wed Dec 23, 2009 2:51 am

You can add the assembly and the namespace to the surrounding class tag:

<class name="DB_Associate, <assembly>" lazy="false" table="Associate" assembly="<assembly>" namespace="="<assembly>.DBWrappers">

Than you don't need to use fully qualified references.

jfputnam2 · **Posted:** Wed Dec 23, 2009 5:56 pm

Thanks,

Thats good information

jfputnam2 · **Posted:** Mon Dec 28, 2009 4:30 pm

Wolfgang,

Actually NHibernate does not have the assembly or namespace defined in the documenation and it throws an exception when you have it in the xml. That may be a hibernate feature that has not been tranfered over. It would be a nice one though.

Thanks,

---John Putnam

wolli · **Posted:** Tue Dec 29, 2009 5:09 am

Sorry, they are not defined on the class, but the outer hibernate-mapping element:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" assembly="sx.business" namespace="sx.business.partner">