title: My SQL ADDDATE FUNCTION is not working in CREATE TABLE
body: <p>I want to create a table in which there is <code>OPENDATE</code> field. The default value for which should be 30 days earlier to system date.</p>
  
  <pre><code>CREATE TABLE bugs (
      ID INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
      TITLE VARCHAR(20) NOT NULL,
      SEVERITY INT NOT NULL check(SEVERITY&gt;0 &amp;&amp; SEVIRITY&lt;5),
      OPENDATE DATETIME NOT NULL DEFAULT ADDDATE(CURRENT_TIMESTAMP,-30),
      CLOSEDATE DATETIME DEFAULT NULL
  ) ENGINE=MyISAM DEFAULT CHARSET=latin1;
  </code></pre>
  
  <hr>
  
  <ol>
  <li><p>This gives error at <code>ADDDATE</code> function. Can I not use functions at the table creation time? If no, what's the solution, and If yes, why this is not working?</p></li>
  <li><p>I also noticed that the identifier <code>CURRENT_DATE</code> is not recognized. Why?</p></li>
  </ol>