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POMapping hibernate components to a separate table
 

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    <p>Is it possible to configure Hibernate to store a component class in a separate table?</p> <p>Take the following example:</p> <pre><code>&lt;class name="test.ClassA"&gt; &lt;property name="propA"/&gt; &lt;component name="componentProp" class="test.ClassB"&gt; &lt;property name="propB"/&gt; &lt;/component&gt; &lt;/class&gt; </code></pre> <p>This maps to a table called <code>MyClass</code> with two columns <code>propA</code> and <code>propB</code>. What I want is to map the properties of the component to a table called <code>ClassB</code>.</p> <p>What I <em>don't</em> want to do is configure <code>ClassB</code> as an entity in itself (it has no meaningful identity outside of <code>ClassA</code>), so that rules out a normal association. Also, I cannot modify the object model (it's generated code), so I can't introduce an ID property to <code>ClassB</code>.</p> <p>This seems to be a gap in Hibernate's functionality - the &lt;component> mapping performs "multiple-classes-to-one-table", and &lt;join> does "one-class-to-multiple-tables", but oddly there's no apparent way of doing "multiple-classes-to-multiple-tables", without resorting to entity associations.</p> <p>My rationale for wanting this is that I want my DB schema to resemble the object model as closely as is practical, and that includes separate tables for the <code>ClassB</code> component. I understand that this wouldn't scale - you couldn't do nested components, for example, but this isn't a problem in this particular situation.</p>
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    1. USRich Seller
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