title: how to output in 5-minute interval?(mysql )
body: <p>I want to output a time interval.<br>
  Stores at one minute intervals.<br>
  query is:</p>
  
  <pre><code>select datetime + INTERVAL 5 MINUTE
  from ch1
  where datetime between '2016-07-12 17:26:00' and '2016-07-13 09:17:00'
  </code></pre>
  
  <p>but output is</p>
  
  <pre><code>2016-07-12 17:31:00  
  2016-07-12 17:32:00  
  2016-07-12 17:33:00  
  2016-07-12 17:34:00  
  2016-07-12 17:35:00  
  2016-07-12 17:36:00 ...
  </code></pre>
  
  <p>I want to output.</p>
  
  <pre><code>2016-07-12 17:26:00  
  2016-07-12 17:31:00  
  2016-07-12 17:36:00  
  2016-07-12 17:41:00  
  2016-07-12 17:46:00  
  2016-07-12 17:51:00 ...
  </code></pre>