How to allow code block in wordpress comments

WordPress allows it by default ( of course, plugins or theme can change that ). The code should be wrapped in <code></code>, like this:

<code>
global $var;
echo $var;
</code>

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)