title: How to remove duplicates in hive string?
body: <p>I have a comma-separated column(string) with duplicate values. I want to remove duplicates:<br/>
  e.g.</p>
  <pre><code>column_name
  -----------------
  gun,gun,man,gun,man
  shuttle,enemy,enemy,run
  hit,chase
  </code></pre>
  <p>I want result like:</p>
  <pre><code>column_name
  ----------------
  gun,man
  shuttle,enemy,run
  hit,chase
  </code></pre>
  <p>I am using hive database.</p>