Using 'if (isset($_GET' to retrieve composite key instead of primary key
<p>If I was to get a primary key then I would do this:</p>

<pre><code>if (isset($_GET['item_id']))
</code></pre>

<p>But if the table had a composite key (2 attributes that act as a primary key), how would I do this? My 2 attributes acting as a composite key are item_id and size_id</p>
