Doctrine, ignore some fields to persist and null
<p>given a user:</p>

<pre><code>id, name, password
</code></pre>

<p>so I want to modify him, and set a name to it. But then if I persists, his password will be rewritten (set to empty), even though I didnt set it. But here is the <code>nullable=true</code> annotation! Right now it seems to work - but this way its impossible to persist if I want to set it <code>null</code> itself. Then how?</p>