title: PDO bind unknown number of parameters?
body: <pre><code>$statement = $db-&gt;prepare('SELECT blah FROM blah_table WHERE blahID IN (:a, :b, :c)');
  </code></pre>
  
  <p>What if the number of parameters is unknown until run-time? The only thing I can think of doing is a hacky kind of building of the sql string to make as many parameter placeholders as I need.</p>