Recursive relationship ... duplicate import error

msirfani · **Posted:** Tue Mar 30, 2004 6:31 am

New to Hibernate ... using hibernate 2.1.2 with Struts.

I have Organisation with recursive reloationship ... (one-to-many relationship) ... I have the following hbm file ...

Code:

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
   <class name="mydomain.Organisation" table="ORGANIZATIONS">

        <id name="orgCode" type="string" length="20">
           <column name="org_code" sql-type="varchar(20)" not-null="true"/>
           <generator class="assigned"/>
        </id>

        <property name="name" column = "org_name"/>
        <property name="shortName" column ="short_name"/>
        <property name="sapCode" column="sap_code"/>
      <property name="divHead" column="div_head"/>
      <property name="phone" column="tel"/>
      <property name="mpaGroup" column="mpa_group" />
      <!--many-to-one name= "parentCode" column= "prnt_org_code"/ -->
      
      <set name="organisations" cascade="all" inverse="true">
         <key  column="org_code" foreign-key="prnt_org_code" />
         <one-to-many class="mydomain.Organisation" />
      </set> 
   </class>

</hibernate-mapping>

When running I am getting and error duplicate import ... I found in the forum that there must be some error in the mapping file.

Will you please let me know is there any error in this mapping document?

Thanks

santosh · **Posted:** Tue Mar 30, 2004 6:56 am

Change the line

<key column="org_code" foreign-key="prnt_org_code" />

to

<key column="prnt_org_code" />

thanks
santosh

Saurabh · **Joined:** Tue Mar 23, 2004 12:21 pm **Posts:** 11

Hello Misirfani,
Just wanted to know , if this solution worked for you. I have a same problem.
According to documentation 'Collections may not contain other collections'. As i can see from the code sniplet that Your master object and the asscoate object is same. If the Master object has a set , so will be the associate object.
But that may not work according the documentaion. However if this has worked for you , I will be very interested to know, how?
Thanks

msirfani · **Posted:** Wed Mar 31, 2004 12:58 am

Thanks Santosh ...

It did worked ... How ... it is very difficult for me to answer ... (since I am new to both Java as well as Hibernate) but I can see from the Debug window that the parent collection Organisation do have a set named organisations of type net.sf.hibernate.collection.Set

May be they are yet to update the Documentation.

Once again ... Thanks Santosh.

santosh · **Posted:** Wed Mar 31, 2004 1:28 am

Hi msirfani,

It worked because within the following Set element

<set name="organisations" cascade="all" inverse="true">
<key column="prnt_org_code" />
<one-to-many class="mydomain.Organisation" />
</set>

, the key column denotes the foreign key. Yours is a case of self-referential integrity where the foreign key is in the same table.

The documentation , I believe,is sufficient as far as collections and parent-child relation ships are concerned.

Go thru the following link for more info.
http://www.xylax.net/hibernate/

thanks
santosh

msirfani · **Posted:** Sat Apr 03, 2004 6:15 am

Thanks santosh I got it ... now I know what is the mistake!