title: Suppressing a repeated column value in PostgreSQL?
body: <p>For example if we have the values:</p>
  
  <pre><code>username             Category
  -------------------- ----------
  Brian                cs
  Tom                  cs
  Joe                  cs
  Allen                cs
  Bill                 ts
  Steven               ts
  Fred                 ts
  Ted                  ts
  </code></pre>
  
  <p>I Need an Output  as</p>
  
  <pre><code>username             Category
  -------------------- ----------
  Brian                cs
  Tom                  
  Joe                  
  Allen                
  Bill                 ts
  Steven               
  Fred                 
  Ted      
  </code></pre>
  
  <p>I have Tried</p>
  
  <p>1)  <a href="https://stackoverflow.com/questions/3682956/t-sql-how-to-select-rows-without-duplicate-values-from-one-column">T-SQL How to select rows without duplicate values from one column?</a> </p>
  
  <p>2) <a href="http://www.rajapet.com/2010/04/suppressing-repeated-column-value-in.html" rel="nofollow noreferrer">http://www.rajapet.com/2010/04/suppressing-repeated-column-value-in.html</a></p>
  
  <p>3) <a href="https://stackoverflow.com/questions/12239169/how-to-select-records-without-duplicate-on-just-one-field-in-sql">How to select records without duplicate on just one field in SQL?</a></p>
  
  <p>Nothing Work well ( What i Expected) </p>
  
  <p>Is there any other way ?</p>