title: Using DATADIFF in a query (PL/SQL)
body: <p>I'm trying to use a DataDiff in a query so that I can also "print" the difference between the two dates, in seconds.
  The query looks like this:</p>
  
  <pre><code>SELECT vr.CodeR, vi.DateU, vl.originU, vl.destinyU, (DATEDIFF(second,vi.plannedDate,vi.SetDate) AS DiffDate)
  FROM RegularU vr, Connection vl, InstantU vi
  WHERE vl.codeU=vr.codeU AND vr.CodeR=vi.CodeR
  </code></pre>
  
  <p>But when I try to run it I have the error "Missing select word".
  Is there a way so that I can do this in a query?</p>
  
  <p>Thanks in advance</p>