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    <p>JPA's behaviour is correct (meaning <em>as per the specification</em>): objects aren't deleted simply because you've removed them from a OneToMany collection. There are vendor-specific extensions that do that but native JPA doesn't cater for it.</p> <p>In part this is because JPA doesn't actually know if it should delete something removed from the collection. In object modeling terms, this is the difference between <em>composition</em> and "aggregation*.</p> <p>In <em>composition</em>, the child entity has no existence without the parent. A classic example is between House and Room. Delete the House and the Rooms go too.</p> <p><em>Aggregation</em> is a looser kind of association and is typified by Course and Student. Delete the Course and the Student still exists (probably in other Courses).</p> <p>So you need to either use vendor-specific extensions to force this behaviour (if available) or explicitly delete the child AND remove it from the parent's collection.</p> <p>I'm aware of:</p> <ul> <li><a href="http://www.google.com.au/search?rlz=1C1GGLS_enAU353AU354&amp;sourceid=chrome&amp;ie=UTF-8&amp;q=hibernate" rel="noreferrer">Hibernate</a>: cascade delete_orphan. See <a href="http://docs.jboss.org/hibernate/core/3.3/reference/en/html/objectstate.html#objectstate-transitive" rel="noreferrer">10.11. Transitive persistence</a>; and</li> <li><a href="http://www.eclipse.org/eclipselink/" rel="noreferrer">EclipseLink</a>: calls this "private ownership". See <a href="http://www.eclipse.org/eclipselink/documentation/2.5/jpa/extensions/a_privateowned.htm" rel="noreferrer">How to Use the @PrivateOwned Annotation</a>.</li> </ul>
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    1. COthanks the nice explanation. so it is as i feared. (i did some search/ reading before i asked, just wanting to be save). somehow i start regretting the decision to use JPA API and nit Hibernate directly .. I will try Chandra Patni pointer and use the hibernate delete_orphan cascade type.
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    2. COI have a kind of similar question about this. Would be be kind take a look at this post here, please? http://stackoverflow.com/questions/4569857/jsf-how-to-update-the-list-after-delete-an-item-of-that-list
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    3. COWith JPA 2.0, you can now use the option orphanRemoval = true
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