Query mapped to wrong table with one table per subclass

pierre-yves · **Posted:** Thu Mar 11, 2004 11:21 am

Using hibernate 2.0.3

I have a mapping with a one table per sublass strategy.

Code:

<hibernate-mapping>
    <class
        name="com.fnac.customer.mailfollowup.bean.AbstractMailParam"
        table="COMMON_MAIL_PARAM"
        dynamic-update="false"
        dynamic-insert="false"
    >

        <id
            name="id"
            column="COMMON_MAIL_PARAM_ID"
            type="java.lang.Long"
            unsaved-value="null"
        >
            <generator class="sequence">
                <param name="sequence">SEQ_DEFAULT</param>
            </generator>
        </id>

        <version
            name="versionNumber"
            type="int"
            column="VERSION_NUMBER"
        />

  
        <many-to-one
            name="thePartner"
            class="com.fnac.customer.mailfollowup.bean.admin.Partner"
            cascade="none"
            outer-join="auto"
            update="true"
            insert="true"
            column="PARTNER_ID"
        />

        <joined-subclass
            name="com.fnac.customer.mailfollowup.bean.MailParam"
            table="MAIL_PARAM"
            dynamic-update="false"
            dynamic-insert="false"
        >
        <key
            column="COMMON_MAIL_PARAM_ID"
        />

        <many-to-one
            name="mailProcess"
            class="com.fnac.customer.mailfollowup.bean.MailProcess"
            cascade="none"
            outer-join="auto"
            update="true"
            insert="true"
            column="PROCESS_ID"
        />

        </joined-subclass>

    </class>
    <class
        name="com.fnac.customer.mailfollowup.bean.AbstractProcess"
        table="PROCESS"
        dynamic-update="false"
        dynamic-insert="false"
        discriminator-value="null"
    >

        <id
            name="id"
            column="PROCESS_ID"
            type="java.lang.Long"
            unsaved-value="null"
        >
            <generator class="sequence">
                <param name="sequence">SEQ_PROCESS</param>
            </generator>
        </id>

        <discriminator
            column="PROCESS_TYPE"
            type="java.lang.Integer"
        />

        <version
            name="versionNumber"
            type="int"
            column="VERSION_NUMBER"
        />


        </subclass>
        <subclass
            name="com.fnac.customer.mailfollowup.bean.MailProcess"
            dynamic-update="false"
            dynamic-insert="false"
            discriminator-value="1"
        >

        <many-to-one
            name="mailParam"
            class="com.fnac.customer.mailfollowup.bean.MailParam"
            cascade="none"
            outer-join="auto"
            update="true"
            insert="true"
            column="PARAM_ID"
        />

        </subclass>

    </class>
    <class
        name="com.fnac.customer.mailfollowup.bean.admin.Partner"
        table="PARTNER"
        dynamic-update="false"
        dynamic-insert="false"
    >

        <id
            name="id"
            column="PARTNER_ID"
            type="java.lang.Long"
            unsaved-value="null"
        >
            <generator class="sequence">
                <param name="sequence">SEQ_DEFAULT</param>
            </generator>
        </id>

        <version
            name="versionNumber"
            type="int"
            column="VERSION_NUMBER"
        />
        <property
            name="name"
            type="java.lang.String"
            update="true"
            insert="true"
            column="NAME"
        />

    </class>
</hibernate-mapping>

Then I do a simple query trying:

Code:

session.find( "select process.mailParam.thePartner.name" 
                + " from MailProcess as process ");

Then hibernate tries to get thePartner property from the subclass and not the parent class. As a consequence I get an SQL Exception.
How come it doesn't get the property from the parent class ?
Is ther any workaround for that ?
Thanks.

Code:

java.sql.SQLException: ORA-00904: "MAILPARA1__1"."PARTNER_ID" : identificateur non valide

   at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:180)
   at oracle.jdbc.ttc7.TTIoer.processError(TTIoer.java:208)
   at oracle.jdbc.ttc7.Oall7.receive(Oall7.java:543)
   at oracle.jdbc.ttc7.TTC7Protocol.doOall7(TTC7Protocol.java:1451)
   at oracle.jdbc.ttc7.TTC7Protocol.parseExecuteDescribe(TTC7Protocol.java:651)
   at oracle.jdbc.driver.OracleStatement.doExecuteQuery(OracleStatement.java:2117)
   at oracle.jdbc.driver.OracleStatement.doExecuteWithTimeout(OracleStatement.java:2331)
   at oracle.jdbc.driver.OraclePreparedStatement.executeUpdate(OraclePreparedStatement.java:422)
   at oracle.jdbc.driver.OraclePreparedStatement.executeQuery(OraclePreparedStatement.java:366)
   at net.sf.hibernate.impl.BatcherImpl.getResultSet(BatcherImpl.java:71)
   at net.sf.hibernate.loader.Loader.getResultSet(Loader.java:551)
   at net.sf.hibernate.loader.Loader.doFind(Loader.java:140)
   at net.sf.hibernate.loader.Loader.find(Loader.java:620)
   at net.sf.hibernate.hql.QueryTranslator.find(QueryTranslator.java:928)
   at net.sf.hibernate.impl.SessionImpl.find(SessionImpl.java:1343)
   ... 29 more

anthony · **Posted:** Thu Mar 11, 2004 11:35 am

in hibernate.hbm.xml, use show-sql = true, then trace the generated SQL, there might be an error in one of the column name

pierre-yves · **Posted:** Thu Mar 11, 2004 11:39 am

I did, but it's true that I didn't post it. Here it is ;-)

Code:

Hibernate: select partner2_.NAME as x0_0_ from PROCESS mailproc0_, MAIL_PARAM mailpara1_, PARTNER partner2_ where mailproc0_.PROCESS_TYPE=1 and mailproc0_.PARAM_ID=mailpara1_.COMMON_MAIL_PARAM_ID and mailpara1__1.PARTNER_ID=partner2_.PARTNER_ID

As you can see, it doesn't select the parent class table where is the partner property.

anthony · **Posted:** Thu Mar 11, 2004 12:25 pm

Are you sure you're in a limitation?
see

http://www.hibernate.org/hib_docs/refer ... ritance-s2

pierre-yves · **Posted:** Thu Mar 11, 2004 12:43 pm

I am using the table per sublass strategy.
I don't see any limitations in the doc for this strategy.

pierre-yves · **Posted:** Thu Mar 11, 2004 12:53 pm

A workaround is to hardcode the join

Code:

session.find(select abstractParam.thePartner.name from Mailprocess as process, AbstractParam as abstractParam where process.mailParam.id = abstractParam.id)

I feel although that this join shoud be done by hibernate.

anthony · **Posted:** Thu Mar 11, 2004 1:09 pm

i think we're going to have a detailled explanation by the hibernate team

there must be a reason why it's working like this

emmanuel · **Posted:** Fri Mar 12, 2004 6:34 am

Hum sounds like Hibernate forgot COMMON_MAIL_PARAM mailpara1__1 in the from clause. I'll ckeck that deeper