title: PDO PARAM_STR and length
body: <p>I don't understand the length option in a <code>PDO PARAM_*</code> statement.</p>
  
  <p>Does the length indicate an amount of required characters, or is it a max?</p>
  
  <p>Example:</p>
  
  <pre><code>$sth-&gt;bindParam(2, $color, PDO::PARAM_STR, 12);
  </code></pre>
  
  <p>Does this require 12 characters, or is this limiting it to 12 characters? Or, am I completely misunderstanding what this is doing? </p>