title: How to make column values more presentable
body: <p>I have a table containing the following fields: </p>
  
  <ul>
  <li>version  </li>
  <li>id   </li>
  <li>set_value  </li>
  <li>marker</li>
  </ul>
  
  <p>I want to write a SELECT statement to query them. However, the values in the column <code>marker</code> are not easily readable. I would like to present a substring of that column. My question is how do I do this?</p>