title: Oracle show columns as row
body: <p>How can i convert multiple column to row accoding by followed sample? For solution, i inspected many sample for example pivot, decode etc. but i did not reach absolute solution.</p>
  
  <pre><code>+---------+---------+---------+---------+
  |  COL_1  |  COL_2  |  COL_3  |  COL_4  |
  +---------+---------+---------+---------+
  
  I wanna make columns like this;    
  
  +---------+
  |  COL_1  |
  +---------+
  |  COL_2  |
  +---------+
  |  COL_3  |
  +---------+
  |  COL_4  |
  +---------+
  </code></pre>