title: How to calculate difference between two dates in oracle 11g SQL
body: <p>When I am trying to calculate the date difference by using datediff function it showing that invalid identifier.  </p>
  
  <pre><code>SELECT DATEDIFF(day,'2008-08-05','2008-06-05') AS DiffDate from da_static_trade.
  
  Error : invalid identifier.
  </code></pre>
  
  <p>Can you please tell me what is the function to calculate date difference.</p>