Hello,

I have a class (ProblemSolvingEntry) with one-to-one mappings to three other classes (ReframingEntry, CommunicatingEntry, DoingEntry). Each of the three classes have keys pointing back to ProblemSolvingEntry. All four of the classes are subclasses of the same superclass (notebook.Entry) and are stored in the same table (implementing the "table per class hierarchy" design). The three subclasses all use the same column to store their key pointing to ProblemSolvingEntry. The problem is, when hibernate attempts load ProblemSolvingEntry and then loads one of the three other classes, it does not use the discriminator in the query. The DB returns the rows for all three classes instead of just the one, and hibernate throws an exception because more than one row is returned for a one-to-one mapping. Is there any way I can get hibernate to add a check on the discriminator to the WHERE clause? Any help is greatly appreciated...

Hibernate version:
hibernate 2
Mapping documents:
<class name="edu.umich.med.cbtlite.notebook.Entry"
table="NotebookEntry" discriminator-value="ENTRY">
<!-- "My Challenges" subclass -->
<subclass name="edu.umich.med.cbtlite.notebook.MyChallengeEntry"
discriminator-value="MYCHALLENGE">
</subclass>

<!-- "Reframing" subclass -->
<subclass name="notebook.ReframingEntry"
discriminator-value="REFRAMING">
<many-to-one name="problemSolvingEntry" column="F1"
class="notebook.ProblemSolvingEntry"
unique="true"/>
</subclass>

<!-- "Communicating" subclass -->
<subclass name="notebook.CommunicatingEntry"
discriminator-value="COMMUNICATING">
<many-to-one name="problemSolvingEntry" column="F1"
class="notebook.ProblemSolvingEntry"
unique="true"/>
</subclass>

<!-- "Doing" subclass -->
<subclass name="notebook.DoingEntry"
discriminator-value="DOING">
<many-to-one name="problemSolvingEntry" column="F1"
class="notebook.ProblemSolvingEntry"
unique="true"/>
</subclass>

<!-- "Brainstorming" subclass -->
<subclass name="notebook.BrainstormingEntry"
discriminator-value="BRAINSTORMING">
<property name="favorable" column="Extra1"/>
<property name="realistic" column="Extra2"/>
<many-to-one name="problemSolvingEntry" column="F1"/>
</subclass>


<!-- "Problem Solving" subclass -->
<subclass name="notebook.ProblemSolvingEntry" discriminator-value="PROBLEMSOLVING">
<many-to-one name="plannedBehavior" column="F1"/>
<many-to-one name="myChallengeEntry" column="F2"/>
<set name="brainStormingEntries" inverse="true" cascade="all" lazy="true">
<key column="F1"/>
<one-to-many
class="notebook.BrainstormingEntry"/>
</set>
<one-to-one name="reframingEntry"
class="notebook.ReframingEntry"
property-ref="problemSolvingEntry"/>
<one-to-one name="communicatingEntry"
class="notebook.CommunicatingEntry
property-ref="problemSolvingEntry"/>
<one-to-one name="doingEntry"
class="notebook.DoingEntry"
property-ref="problemSolvingEntry"/>
</subclass>
</class>
Code between sessionFactory.openSession() and session.close():

Full stack trace of any exception that occurs:
net.sf.hibernate.HibernateException: More than one row with the given identifier was found: 21430273, for class: notebook.ReframingEntry
at net.sf.hibernate.loader.EntityLoader.load(EntityLoader.java:71)
at net.sf.hibernate.loader.EntityLoader.loadByUniqueKey(EntityLoader.java:55)
at net.sf.hibernate.persister.AbstractEntityPersister.loadByUniqueKey(AbstractEntityPersister.java:1103)
at net.sf.hibernate.impl.SessionImpl.loadByUniqueKey(SessionImpl.java:3839)
at net.sf.hibernate.type.EntityType.resolveIdentifier(EntityType.java:235)
at net.sf.hibernate.impl.SessionImpl.initializeEntity(SessionImpl.java:2194)
at net.sf.hibernate.loader.Loader.doQuery(Loader.java:240)
at net.sf.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:133)
at net.sf.hibernate.loader.Loader.loadEntity(Loader.java:836)
at net.sf.hibernate.loader.Loader.loadEntity(Loader.java:856)
at net.sf.hibernate.loader.EntityLoader.load(EntityLoader.java:59)
at net.sf.hibernate.loader.EntityLoader.load(EntityLoader.java:51)
at net.sf.hibernate.persister.EntityPersister.load(EntityPersister.java:419)
at net.sf.hibernate.impl.SessionImpl.doLoad(SessionImpl.java:2106)
at net.sf.hibernate.impl.SessionImpl.doLoadByClass(SessionImpl.java:1980)
at net.sf.hibernate.impl.SessionImpl.load(SessionImpl.java:1909)
at Test.main(Test.java:95)
Name and version of the database you are using:
mySQL 4.0.20-standard
The generated SQL (show_sql=true):
Hibernate: select problemsol0_.id as id0_, problemsol0_.F1 as F10_, problemsol0_.F2 as F20_, problemsol0_.notebookId as notebookId0_, problemsol0_.timestamp as timestamp0_, problemsol0_.text as text0_ from NotebookEntry problemsol0_ where problemsol0_.id=?
Hibernate: select mychalleng0_.id as id0_, mychalleng0_.notebookId as notebookId0_, mychalleng0_.timestamp as timestamp0_, mychalleng0_.text as text0_ from NotebookEntry mychalleng0_ where mychalleng0_.id=?
Hibernate: select reframinge0_.id as id0_, reframinge0_.F1 as F10_, reframinge0_.notebookId as notebookId0_, reframinge0_.timestamp as timestamp0_, reframinge0_.text as text0_ from NotebookEntry reframinge0_ where reframinge0_.F1=?
Debug level Hibernate log excerpt:
09:52:12,084 DEBUG SessionImpl:2191 - resolving associations for [edu.umich.med.cbtlite.notebook.ReframingEntry#21430275]
09:52:12,084 DEBUG SessionImpl:1975 - loading [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,084 DEBUG SessionImpl:2072 - attempting to resolve [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,100 DEBUG SessionImpl:2088 - resolved object in session cache [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,100 DEBUG SessionImpl:1975 - loading [edu.umich.med.cbtlite.notebook.Notebook#13303809]
09:52:12,100 DEBUG SessionImpl:2215 - done materializing entity [edu.umich.med.cbtlite.notebook.ReframingEntry#21430275]
09:52:12,100 DEBUG SessionImpl:2191 - resolving associations for [edu.umich.med.cbtlite.notebook.ReframingEntry#21430276]
09:52:12,100 DEBUG SessionImpl:1975 - loading [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,100 DEBUG SessionImpl:2072 - attempting to resolve [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,100 DEBUG SessionImpl:2088 - resolved object in session cache [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,100 DEBUG SessionImpl:1975 - loading [edu.umich.med.cbtlite.notebook.Notebook#13303809]
09:52:12,115 DEBUG SessionImpl:2215 - done materializing entity [edu.umich.med.cbtlite.notebook.ReframingEntry#21430276]
09:52:12,115 DEBUG SessionImpl:2191 - resolving associations for [edu.umich.med.cbtlite.notebook.ReframingEntry#21430277]
09:52:12,115 DEBUG SessionImpl:1975 - loading [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,115 DEBUG SessionImpl:2072 - attempting to resolve [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,115 DEBUG SessionImpl:2088 - resolved object in session cache [edu.umich.med.cbtlite.notebook.ProblemSolvingEntry#21430273]
09:52:12,115 DEBUG SessionImpl:1975 - loading [edu.umich.med.cbtlite.notebook.Notebook#13303809]
09:52:12,115 DEBUG SessionImpl:2215 - done materializing entity [edu.umich.med.cbtlite.notebook.ReframingEntry#21430277]
09:52:12,131 DEBUG SessionImpl:560 - closing session
09:52:12,131 DEBUG SessionImpl:3327 - disconnecting session

Code between sessionFactory.openSession() and session.close():

ProblemSolvingEntry pse = (ProblemSolvingEntry) mySQLSession.load(ProblemSolvingEntry.class, new Long(21430273));