not able to delete

Question

Hi I am able to add record but not able to delete record.

It gives the following error:

[ERROR] 2010-02-20 13:38:16 (JDBCExceptionReporter.java:logExceptions:78) ORA-02292: integrity constraint (BANKNET.FK_DDA_DEAL_ADVISOR) violated - child record found
[ERROR] 2010-02-20 13:38:16 (AbstractFlushingEventListener.java:performExecutions:301)   
Could not synchronize database state with session
org.hibernate.exception.ConstraintViolationException: could not delete:   [com.bofa.crme.dda.domain.ManualDDAData#10041]

Here are my mapping files:

Child table:

<hibernate-mapping>
    <class name="com.bofa.crme.dda.domain.DealAdvisor" table="DDA_DEAL_ADVISOR" schema="BANKNET">           
        <composite-id name="comp_id" class="com.bofa.crme.dda.domain.DealAdvisorPK">
            <key-property  name="advisorNm" column="ADVISOR_NM" type="java.lang.String"  length="100" access="property"/>
            <key-many-to-one  name="ddaDeal" column="DDA_DEAL_NO" class="com.bofa.crme.dda.domain.ManualDDAData" />
        </composite-id>
        <property name="modifiedBy" column="MODIFIED_BY" type="java.lang.String" update="true" insert="true" access="property" />
        <property name="modifiedDt" column="MODIFIED_DATE" type="java.util.Date" update="true" insert="true" access="property"/>
    </class>
</hibernate-mapping>

Parent table:

<hibernate-mapping>
    <class name="com.bofa.crme.dda.domain.ManualDDAData" table="DDA_DEAL" schema="BANKNET" >
        <id name="ddaDealNumber" column="DDA_DEAL_NO" type="java.lang.Long">
            <generator class="sequence">
                <param name="sequence">BANKNET.DDA_DEAL_ID_SEQ</param>
            </generator>
        </id>
        <property name="clientGCI" type="java.lang.String" update="true" insert="true" access="property" column="GCI" />
        <set name="dealAdvisors" inverse="true" cascade="all,all-delete-orphan" lazy="false">
            <key  column="DDA_DEAL_NO" not-null="true" on-delete="cascade"/>
            <one-to-many class="com.bofa.crme.dda.domain.DealAdvisor" />
        </set>
    </class>
</hibernate-mapping>

Anyone know why it is not working ?