SQL JPA - Multiple columns as primary key
<p>If i want severeal Column to make up an ID.</p>

<p>SQL example :</p>

<pre><code>CONSTRAINT [PK_NAME] PRIMARY KEY ([Column1],[Column2],[Column3])
</code></pre>

<p>How can i do that with a Jpa Entity class ? through columndefinition ?</p>

<p>just setting the id field as:</p>

<pre><code>value = Column1 + Column2 + Column3 // aint working.
</code></pre>