Hi,

<hibernate-mapping>
<class name="adaptation.data.extract.SchemeExtract" table="scheme_extract" optimistic-lock="version">

<id name="id" column="scheme_extract_id" >
<generator class="increment"/>
</id>
<property name="schemeId" column="scheme_id" not-null="true" />

<property name="lastGoodDate" column="last_good_date"/>
<property name="lastGoodSequence" column="last_good_sequence"/>
<property name="nextDueDate" column="next_due_date"/>
<property name="nextDueSequence" column="next_due_sequence"/>
<property name="lastSuccessCount" column="last_success_count"/>
<property name="lastFailureCount" column="last_failure_count"/>

<set name="missingExtracts" lazy="false">
<key column="scheme_extract_id" not-null="true"/>
<one-to-many class="adaptation.data.extract.ExtractMissing" />
</set>

<many-to-one name="extract" column="extract_id" class="adaptation.data.extract.Extract" not-null="true" lazy="false" />
</class>
</hibernate-mapping>


<hibernate-mapping>
<class name="adaptation.data.extract.ExtractMissing" table="missing_extract_file" dynamic-update="true" optimistic-lock="version">

<id name="id" column="scheme_extract_id" unsaved-value="null">
<generator class="increment"/>
</id>
<property name="expectedDate" column="expected_date" />
<property name="expectedSequence" column="expected_sequence"/>
</class>
</hibernate-mapping>


EXCEPTION :


org.hibernate.MappingException: Foreign key (FK315B58B3C22D0F39:missing_extract_file [scheme_extract_id])) must have same number of columns as the referenced primary key (scheme_extract [scheme_id,extract_id])

can u please help me out...
_________________
Thanks
Babu

Your primary key is a compound key, but the foreign key doesn't share the same number of properties as the compound key. I think that's the problem.