title: Codeigniter PDO integration
body: <p>i did lot of research on the web but i didnt find anything that could help me to use PDO in codeigniter. I saw in the change lof of CI 2.1.0(i think) that pdo driver was added to the framwork.
  I ended up now with a database.php config file that looks like this:</p>
  
  <pre><code>$db['default']['hostname'] = 'mysql:host=myhostname;port=myport'; 
  $db['default']['username'] = 'myusername';
  $db['default']['password'] = 'mypassword'; 
  $db['default']['database'] = 'mydb'; 
  $db['default']['dbdriver'] = 'pdo';
  </code></pre>
  
  <p>So now(after a lot of wasted time to get the snippet above to work -.- ) i receive no error about connection, but HOW TO EXECUTE QUERY NOW? i cant figure out what syntax will work and how to build queries. Anyone have hints?</p>
  
  <p>PS: if you're wordering about why i need pdo in ci, the answer is my boss want me to create a structured enviroment with:</p>
  
  <ol>
  <li>CI 2.x + (done)</li>
  <li>Smarty 3 (done)</li>
  <li>PhpUnit (not yet)</li>
  <li>PDO (not yet)</li>
  </ol>
  
  <p>so if you have also any hints for integrate phpunit feels free to answer. Ty in advance</p>