title: Field 'user_data' doesn't have a default value in CI 2.0.3
body: <p>I used CI's user guide to create my session table.</p>
  
  <pre><code>CREATE TABLE IF NOT EXISTS  `sessions` (
      session_id varchar(40) DEFAULT '0' NOT NULL,
      ip_address varchar(16) DEFAULT '0' NOT NULL,
      user_agent varchar(120) NOT NULL,
      last_activity int(10) unsigned DEFAULT 0 NOT NULL,
      user_data text NOT NULL,
      PRIMARY KEY (session_id),
      KEY `last_activity_idx` (`last_activity`)
  );
  </code></pre>
  
  <p>This error shows whenever I have <code>$db['default']['stricton'] = TRUE</code> in my database.php</p>
  
  <blockquote>
    <p>Error Number: 1364</p>
    
    <p>Field 'user_data' doesn't have a default value</p>
    
    <p>INSERT INTO <code>sessions</code> (<code>session_id</code>, <code>ip_address</code>, <code>user_agent</code>,
    <code>last_activity</code>) VALUES ('2b92823888c4c5eb4b5b2ae25282ce9e',
    '192.168.1.4', 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1
    (KHTML, like Gecko) Chrome/14.0.835.186 Safari/535.1', 1317346730)</p>
    
    <p>Filename: libraries/Session.php</p>
    
    <p>Line Number: 327</p>
  </blockquote>
  
  <p>However, I want to enforce strict SQL.</p>