title: Return distinct values from multiple columns in one query
body: <p>i have searched but i did not find any good answer actually i got the distinct value but the problem is i am applying query on two columns it should return distinct values but it is returning these values</p>
  
  <pre><code>Au |FAA303
  Au |FAA505
  </code></pre>
  
  <p>From my table i want to appear <strong><code>Au</code></strong> only one time as it is now associated with the <strong><code>FAA303</code></strong> and <strong><code>FAA505</code></strong></p>
  
  <p>What i want is like this  </p>
  
  <pre><code>Au |FAA303
     |FAA505
  </code></pre>
  
  <p>This is my query in postgresql. I am kinda new to the database queries.</p>
  
  <pre><code>select distinct column1, column2
  from table_name
  </code></pre>