title: replace datetime in mysql
body: <p>after</p>
  
  <pre><code>mysql&gt; select now()
  </code></pre>
  
  <p>got</p>
  
  <pre><code>2012-03-29 14:07:10
  </code></pre>
  
  <p>if 5 minutes is my interval, so, my question is how to:</p>
  
  <p>change 07 as 05, seconds will be always zero</p>
  
  <p>if i got minute 11, than, it should be replace as 10</p>