title: How to delete duplicates but keep one when all tuples are identical in duplicates and original? In postgreSQL
body: <p>Suppose we have below table.<br />
  How to delete 2 duplicates and keep one? My code deletes all of them.</p>
  <pre><code>+----+-------+
  | ID | NAME  |
  +----+-------+
  |  2 | ARK   |
  |  3 | CAR   |
  |  9 | PAR   |
  |  9 | PAR   |
  |  9 | PAR   |
  +----+-------+
  </code></pre>