I am trying to map a class and sublass but when i try to build session factory it gives :

net.sf.hibernate.MappingException: discriminator mapping required for polymorphic persistence
at net.sf.hibernate.persister.EntityPersister.<init>(EntityPersister.java:683)
at net.sf.hibernate.persister.PersisterFactory.create(PersisterFactory.java:29)
at net.sf.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:207)
at net.sf.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:627)

I am mapping subclass as :
<subclass name="com.bunge.bgm.contract.business.domain.period.AccountingPeriod">
<property name="_isClosed" column="OPEN_CLOSE"/>
<property name="_isOpen" column="OPEN_CLOSE"/>
</subclass>

How to give mapping for polymorphic persistence ? It is still not clear from the stack trace. I tried to find an example but didnt get. Please help.

this is the class where exception is thrown.

10:47:06,627 INFO ReflectHelper:328 - reflection optimizer disabled for: com.bunge.bgm.contract.business.domain.period.Period, InvocationTargetException: null

I am having a Super and Subclass and subclass is mapped but while creating session factory the exception is thorwn.
Can i find a sample example implementing SUper and Subclass relationship ?
Thanks in advance.

What Hibernate version you are using? I had expected another MappingException, cause you are using the column OPEN_CLOSE in two different properties.

You need to add a discriminator-value attribute to your subclass AND and discriminator tag to your master class.

Have a look at section 4.1 of hibernate reference guide.

When your mapping will be corrected, the next error will be the one andread points to you : you cannot map 2 read/write properties on the same column

i m using HIbernate2.0.3 and it works this way :
<property name="_isClosed" column="OPEN_CLOSE" insert="false" update="false"/>
<property name="_isOpen" column="OPEN_CLOSE" insert="false" update="false"/>

I think it will work then.

Thanks for the information. I added discriminator-value attribute to subclass and discriminator element for super class and then the discriminator mapping problem is solved. Thanks once again.

This info shouldn't be required according to the hibernate docs. Is this a bug?

From the overview doc:
discriminator-value (optional - defaults to the class name): A value that distiguishes individual subclasses.

From the DTD:
<!ELEMENT discriminator (column?)>
<!ATTLIST discriminator column CDATA #IMPLIED> <!-- default: "class"|none -->
...
<!ATTLIST subclass discriminator-value CDATA #IMPLIED> <!-- default: unqualified class name | none -->

The <discriminator> element is required if the <class> has <subclass>es. The discriminator-value attribute is always optional.

It would be helpful if the docs stated this little bit of info.

It didn't cost me much time;because I found this post; but I interpreted the docs that it was optional as well. Rather than optional EXCEPT when actually subclassed.

Troy

OK I have tried this 2 ways and I STILL get the error:

discriminator mapping required for polymorphic persistence

net.sf.hibernate.MappingException: discriminator mapping required for polymorphic persistence at net.sf.hibernate.persister.EntityPersister.(EntityPersister.java:733) at net.sf.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:41) at net.sf.hibernate.impl.SessionFactoryImpl.(SessionFactoryImpl.java:137) at net.sf.hibernate.cfg.Configuration.buildSessionFactory


Here was my last attempt. (all in base class mapping file)
I also tried to put the subclass in its own xml.

<?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="com.poc2.model.hibernate.staffing.StaffingOrder"
table="StaffingOrder"
discriminator-value="StaffingOrder"
>

<meta attribute="class-description" inherit="false">
@hibernate.class
table="StaffingOrder"
discriminator-value="StaffingOrder"
</meta>

<id
name="staffingOrderId"
type="java.lang.String"
column="staffingOrderId"
>
<meta attribute="field-description">
@hibernate.id
generator-class="assigned"
type="java.lang.String"
column="staffingOrderId"

</meta>
<generator class="net.sf.hibernate.id.SQLServerGUIDGenerator" />
</id>


<property
name="requiredResponseDate"
type="java.sql.Timestamp"
column="requiredResponseDate"
length="23"
>
<meta attribute="field-description">
@hibernate.property
column="requiredResponseDate"
length="23"
</meta>
</property>
<property
name="multiVendorDistribution"
type="boolean"
column="multiVendorDistribution"
not-null="true"
length="1"
>
<meta attribute="field-description">
@hibernate.property
column="multiVendorDistribution"
length="1"
not-null="true"
</meta>
</property>
<property
name="userArea"
type="java.lang.String"
column="userArea"
length="2000"
>
<meta attribute="field-description">
@hibernate.property
column="userArea"
length="2000"
</meta>
</property>
<property
name="positionQuantity"
type="java.lang.Integer"
column="positionQuantity"
length="10"
>
<meta attribute="field-description">
@hibernate.property
column="positionQuantity"
length="10"
</meta>
</property>
<property
name="positionQuanityOpen"
type="java.lang.Integer"
column="positionQuanityOpen"
length="10"
>
<meta attribute="field-description">
@hibernate.property
column="positionQuanityOpen"
length="10"
</meta>
</property>
<property
name="createdOn"
type="java.sql.Timestamp"
column="createdOn"
length="23"
>
<meta attribute="field-description">
@hibernate.property
column="createdOn"
length="23"
</meta>
</property>
<property
name="createdBy"
type="java.lang.String"
column="createdBy"
length="64"
>
<meta attribute="field-description">
@hibernate.property
column="createdBy"
length="64"
</meta>
</property>
<property
name="lastUpdatedOn"
type="java.sql.Timestamp"
column="lastUpdatedOn"
length="23"
>
<meta attribute="field-description">
@hibernate.property
column="lastUpdatedOn"
length="23"
</meta>
</property>
<property
name="lastUpdatedBy"
type="java.lang.String"
column="lastUpdatedBy"
length="64"
>
<meta attribute="field-description">
@hibernate.property
column="lastUpdatedBy"
length="64"
</meta>
</property>

<!-- associations -->
<!-- bi-directional many-to-one association to OrderType -->
<many-to-one
name="orderType"
class="com.poc2.model.hibernate.staffing.OrderType"
not-null="true"
>
<meta attribute="field-description">
@hibernate.many-to-one
not-null="true"
@hibernate.column name="orderType"
</meta>
<column name="orderType" />
</many-to-one>

<!-- bi-directional many-to-one association to OrderStatus -->
<many-to-one
name="orderStatus"
class="com.poc2.model.hibernate.staffing.OrderStatus"
not-null="true"
>
<meta attribute="field-description">
@hibernate.many-to-one
not-null="true"
@hibernate.column name="orderStatus"
</meta>
<column name="orderStatus" />
</many-to-one>





<subclass name="com.poc2.view.struts.wrapper.staffing.JobOffer"
discriminator-value="JobOffer"
>
<property name="actionFlag" type="string"/>
</subclass>

</class>
</hibernate-mapping>




What am I doing wrong now?

I am trying to use my

Add the <discriminator> element in the master class. As per the doc and gavin's answer.

The xml above IS the master class.
It does have the discriminator element.

Unless I misinterpret.

Troy

dude, there is no <discriminator> in your mapping, only a discriminator-value

Yes I realized that. Should have followed up this post. Sorry


Thanks