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copied!<blockquote> <p>I know about the existence of the <code>@PrePersist</code> and <code>@PreUpdate</code> annotations, but i don't know how to use their equivalent in my Xml mappings.</p> </blockquote> <p>The Hibernate3 <a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/events.html#objectstate-events" rel="noreferrer">event architecture</a> provides something equivalent and you could register listeners for <code>PreInsertEvent</code>, <code>PreUpdateEvent</code> or <code>SaveOrUpdateEvent</code> (see the <code>org.hibernate.event</code> package for a full list) to set and update the create/update dates.</p> <p>Another approach would be to use an <a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/events.html#objectstate-interceptors" rel="noreferrer">interceptor</a>, either <code>Session</code>-scoped or <code>SessionFactory</code>-scoped and to set both <code>createDate</code> and <code>updateDate</code> in <code>onSave(...)</code>, update the <code>updateDate</code> in <code>onFlushDirty(...)</code>.</p> <hr> <p><strong>Update:</strong> I'm leaving my original suggestions below but I think that the right approach (should have been my initial answer) is to use an interceptor or the event architecture.</p> <p><strike>You could use the <strong><code>generated</code></strong> attribute of the <strong><a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html#mapping-declaration-timestamp" rel="noreferrer"><code>timestamp</code></a></strong> to get <strong><code>creationDate</code></strong> and <strong><code>updateDate</code></strong> generated by the database on insert and on insert and update respectively:</p> <pre><code><class name="MyEntity" table="MY_ENTITY"> <id .../> <timestamp name="createDate" generated="insert" ... /> <timestamp name="updateDate" generated="always" ... /> ... </class> </code></pre> <p>Refer to the section on <a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html#mapping-generated" rel="noreferrer">generated properties</a> for full details.</strike></p> <h3>Option 1</h3> <p>It appears that <strong><code>timestamp</code></strong> doesn't support <a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html#mapping-generated" rel="noreferrer"><strong><code>generatead</code></strong></a> so my suggestion won't work. Nevertheless, having read the documentation more carefully, my understanding is that <strong><code>timestamp</code></strong> is an alternative to versioning and I don't think that it's an appropriate choice for fields like <strong><code>createDate</code></strong> and <strong><code>updateDate</code></strong> (it may work for the later but that's not what <code>timestamp</code> is for). </p> <p>So I would actually still use <a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html#mapping-generated" rel="noreferrer">generated properties</a> <strong>but</strong> with <a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/mapping.html#mapping-declaration-property" rel="noreferrer">simple properties</a> instead of <strong><code>timestamp</code></strong>:</p> <pre><code><class name="MyEntity" table="MY_ENTITY"> <id .../> <property name="createDate" update="false" insert="false" generated="insert" ... /> <property name="updateDate" update="false" insert="false" generated="always" ... /> ... </class> </code></pre> <p>At the database level, this would require using a trigger for <code>updateDate</code> column. For the <code>createDate</code> column, using something like <code>current_timestamp</code> as default value would work nicely. But triggers are maybe not wanted...</p> <h3>Option 2</h3> <p>To avoid the trigger of the <strong>Option 1</strong>, a variation would be to use <code>updateDate</code> for versioning (and thus map it as <code>timestamp</code>):</p> <pre><code><class name="MyEntity" table="MY_ENTITY"> <id .../> <timestamp name="updateDate" ... /> <property name="createDate" update="false" insert="false" generated="insert" ... /> ... </class> </code></pre> <p>Same approach as Option 1 for <code>createDate</code>, use a default value at the database level.</p> <h3>Option 3</h3> <p>See the top of this answer...</p>

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