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POWhy is my multi-level inheritance mapping not working as I would expect it to?
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copied!<p>I have the following entity mappings:</p> <pre><code>// user.cfc component persistent="true" table="user" discriminatorColumn="userTypeID" { property name="id" column="userID" fieldtype="id" generator="identity"; property name="type" fieldtype="many-to-one" cfc="userType" fkcolumn="userTypeID"; } // admin.cfc component extends="user" persistent="true" table="admin" joincolumn="userID" discriminatorValue="3" { property name="id" column="adminID" fieldtype="id" generator="identity"; } // employee.cfc component extends="user" persistent="true" table="employee" joincolumn="userID" discriminatorValue="0" { property name="id" column="employeeID" fieldtype="id" generator="identity"; } // manager.cfc component extends="employee" persistent="true" table="manager" joincolumn="employeeID" discriminatorValue="1" { property name="id" column="managerID" fieldtype="id" generator="identity"; } // intern.cfc component extends="employee" persistent="true" table="intern" joincolumn="employeeID" discriminatorValue="2" { property name="id" column="internID" fieldtype="id" generator="identity"; } </code></pre> <p>Per Henry's suggestion, here are the generated hbmxml files:</p> <pre><code> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class entity-name="user" lazy="true" name="cfc:user" table="user"> <id name="ID" type="int"> <column name="userID"/> <generator class="identity"/> </id> <discriminator column="userTypeID"/> <many-to-one class="cfc:userType" column="userTypeID" insert="false" name="type" update="false"/> </class> </hibernate-mapping>  <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <subclass discriminator-value="3" entity-name="admin" extends="cfc:user" lazy="true" name="cfc:admin"> <join table="admin"> <key column="userID"/> </join> </subclass> </hibernate-mapping>  <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <subclass discriminator-value="0" entity-name="employee" extends="cfc:user" lazy="true" name="cfc:employee"> <join table="employee"> <key column="userID"/> </join> </subclass> </hibernate-mapping>  <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <subclass discriminator-value="1" entity-name="manager" extends="cfc:employee" lazy="true" name="cfc:manager"> <join table="manager"> <key column="employeeID"/> </join> </subclass> </hibernate-mapping>  <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <subclass discriminator-value="2" entity-name="intern" extends="cfc:employee" lazy="true" name="cfc:intern"> <join table="intern"> <key column="employeeID"/> </join> </subclass> </hibernate-mapping> </code></pre> <p>If it's not clear from the mappings, the relationships are as follows:</p> <pre><code>user |- admin |- employee |- manager |- intern </code></pre> <p>The intention is for the <code>type</code> property on the <code>user</code> entity to be populated by the discriminator value of the <code>manager</code> and <code>intern</code> entities. There is code in <code>employee</code>'s constructor that keeps it from being instantiated directly, so a <code>user</code> will always have a <code>type</code>.</p> <p>The entire mapping works fine when reading some already-existing data from the DB. However, I run into problems when I attempt to insert a new record.</p> <p>Assume that the tables involved already have some records populated:</p> <pre><code>user |---------------------| | userID | userTypeID | |---------------------| | 1 | 1 | | 2 | 2 | | 3 | 2 | | 4 | 3 | |---------------------| admin |------------------| | adminID | userID | |------------------| | 1 | 4 | |------------------| employee |---------------------| | employeeID | userID | |---------------------| | 1 | 1 | | 2 | 2 | | 3 | 3 | |---------------------| manager |------------------------| | managerID | employeeID | |------------------------| | 1 | 1 | |------------------------| intern |-----------------------| | internID | employeeID | |-----------------------| | 1 | 2 | | 2 | 3 | |-----------------------| </code></pre> <p>If I were to create a new <code>intern</code> entity and persist it, I would expect three records to be inserted:</p> <pre><code>INSERT user ( userID, userTypeID ) VALUES ( 5, 2 ) INSERT employee ( employeeID, userID ) VALUES ( 4, 5 ) INSERT intern ( internID, employeeID ) VALUES ( 3, 4 ) </code></pre> <p>However, the SQL that actually gets executed is as follows:</p> <pre><code>INSERT user ( userID, userTypeID ) VALUES ( 5, 2 ) INSERT employee ( employeeID, userID ) VALUES ( 4, 5 ) INSERT intern ( internID, employeeID ) VALUES ( 3, 5 ) -- using the new userID instead of the new employeeID </code></pre> <p>Finally, the actual question:</p> <p>Why, when inserting into <code>intern</code>, is it using the <code>userID</code> instead of the <code>employeeID</code>? It's as if Hibernate is ignoring the <code>joincolumn</code> property on <code>intern</code> and just using the <code>joincolumn</code> from <code>employee</code>.</p>

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