title: What does this X in a query using a derived table in MySQL mean?
body: <p>I'm getting my head around using what I think are called 'derived tables' in MySQL and noticed my queries only work when I have this <code>x</code> after the <code>FROM()</code> statement:</p>
  
  <pre><code>SELECT * FROM( &lt;inner select&gt; ) x ORDER BY id ASC
  // -----------------------------^
  </code></pre>
  
  <p>I've looked around and read several articles about derived tables but none of them mention this (all the examples I see don't even utilise it, though my tests return 0 rows without it). I came across it in <a href="https://stackoverflow.com/questions/18651129/count-the-amount-of-occurrences-of-a-another-count-result">an answer to one of my previous questions</a>.</p>
  
  <p>If it makes any difference, I am running the queries via PDO.</p>