title: Update Varchar entries in MySQL table
body: <pre><code>CREATE TABLE `Schedule` (
    `id` smallint(6) NOT NULL AUTO_INCREMENT,
    `name` varchar(30) DEFAULT NULL,
    `deptime` varchar(20) DEFAULT NULL,
    PRIMARY KEY (`id`)
  ) ENGINE=MyISAM AUTO_INCREMENT=3221 DEFAULT CHARSET=latin1;
  </code></pre>
  
  <p>The field <code>deptime</code> contains entries in the following format: <code>2012-09-04 09:17</code>.</p>
  
  <p>Now I need to change the day of all entries in this field, i.e. <code>2013-07-01 09:17</code>. The time, i.e. <code>09:17</code> should not be changed. How can I do this in a quick way using some <code>UPDATE</code> query?</p>