You may not dereference a collection...exception. Why?

dia100 · **Joined:** Mon Sep 08, 2003 4:30 pm **Posts:** 203

Hi All,

Maps:

Code:

    <class name="com.db.device.NEMgmtInfo" table="nemgmtinfo" mutable="true" polymorphism="implicit" dynamic-update="false" dynamic-insert="false">
      <!--cache usage="read-write" /-->
      <id name="id" type="long" unsaved-value="0">
         <generator class="native">
         </generator>
      </id>
      <bag name="cards" lazy="true" inverse="true" cascade="all-delete-orphan">
         <key column="ne_card"/>
         <one-to-many class="com.db.device.NECard"/>
      </bag>
    </class>

    <class name="com.db.device.NECard" table="ne_card" mutable="true" polymorphism="implicit" dynamic-update="false" dynamic-insert="false">
      <id name="id" type="long" unsaved-value="0">
         <generator class="native">
         </generator>
      </id>
      <many-to-one name="ne_card" column="ne_card" class="com.db.device.NEMgmtInfo"/>

</class>

Code:

Code:

         NEMgmtInfo host1 = null;
         host1 = (NEMgmtInfo) session.load(NEMgmtInfo.class, new Long(10));

         List newList =
            session.find(
               "from com.diatem.db.device.NECard as card where card.ne_card.id = ?",
               new Long(host1.getId()),
               Hibernate.LONG);

         host1.setCards(newList);

         NEMgmtInfo host2 = null;
         host2 = (NEMgmtInfo) session.load(NEMgmtInfo.class, new Long(12));

         List newList1 =
line 114:            session.find(
               "from com.diatem.db.device.NECard as card where card.ne_card.id = ?",
               new Long(host2.getId()),
               Hibernate.LONG);

An exception is raised at the 2ns session.find()

Code:

net.sf.hibernate.HibernateException: You may not dereference a collection with cascade="all-delete-orphan"
   at net.sf.hibernate.impl.SessionImpl.updateUnreachableCollection(SessionImpl.java:2887)
   at net.sf.hibernate.impl.SessionImpl.flushCollections(SessionImpl.java:2756)
   at net.sf.hibernate.impl.SessionImpl.flushEverything(SessionImpl.java:2227)
   at net.sf.hibernate.impl.SessionImpl.autoFlushIfRequired(SessionImpl.java:1771)
   at net.sf.hibernate.impl.SessionImpl.getQueries(SessionImpl.java:1536)
   at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1501)
   at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1491)
   at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1487)
   at com.diatem.db.device.api.MainDevice.go(MainDevice.java:114)
   at com.diatem.db.device.api.MainDevice.main(MainDevice.java:74)

Why???

TIA,
--steve p.

dia100 · **Joined:** Mon Sep 08, 2003 4:30 pm **Posts:** 203

I am not getting the error if don't do:

host1.setCards(newList);

dia100 · **Joined:** Mon Sep 08, 2003 4:30 pm **Posts:** 203

Can anybody help me with this?
Someone from Hibernate team, maybe.

Please. Thank you.

emmanuel · **Posted:** Fri Apr 02, 2004 1:47 pm

all-delete-orphan requires to keep the same collection instance (the one Hibernate give) to work (it keeps the collection state).

dia100 · **Joined:** Mon Sep 08, 2003 4:30 pm **Posts:** 203

emmanuel wrote:

all-delete-orphan requires to keep the same collection instance (the one Hibernate give) to work (it keeps the collection state).

So what was I doing wrong?

emmanuel · **Posted:** Fri Apr 02, 2004 1:57 pm

Code:

host1.setCards(newList);

You're setting an new instance

dia100 · **Joined:** Mon Sep 08, 2003 4:30 pm **Posts:** 203

emmanuel wrote:

Code:

host1.setCards(newList);

You're setting an new instance

Thx, Emmanuel.

Still, how am I suppoesed to replace the old collection with a new one if I cannot do

host1.setCards()

thx.

hans · **Joined:** Tue Oct 21, 2003 1:09 pm **Posts:** 4

one way you can do is
Collection col = host1.getCards();
col.clear();
col.addAll(newList);

dia100 · **Joined:** Mon Sep 08, 2003 4:30 pm **Posts:** 203

hans wrote:

one way you can do is
Collection col = host1.getCards();
col.clear();
col.addAll(newList);

thx. it did the trick.