About NSPredicate in Core Data Fetch
<p>I have two entities, User &amp; Message.</p>

<ul>
<li>Message has a created_at timestamp;</li>
<li>Message has a sender[to one relationship with User];</li>
<li>User has a sentMessages[to many relationship with Message];</li>
</ul>

<p>However I want to fetch all users who have sent any messages and with their latest sent message fetched together.</p>

<p>I've try fetch message and set predicate </p>

<pre><code>created_at = sender.sentMessages.@max.created_at
</code></pre>

<p>but the compiler told me unable to parse sql statement?
How can I do that?</p>
