title: How to get date_diff from previous rows in Presto?
body: <p>I'm trying to get a <code>diff_date</code> from Presto from this data. </p>
  
  <pre><code>timespent | 2016-04-09T00:09:07.232Z | 1000          | general
  timespent | 2016-04-09T00:09:17.217Z | 10000         | general
  timespent | 2016-04-09T00:13:27.123Z | 250000        | general
  timespent | 2016-04-09T00:44:21.166Z | 1144020654000 | general
  </code></pre>
  
  <p>This is my query</p>
  
  <pre><code>select _t, date_diff('second', from_iso8601_timestamp(_ts), SELECT from_iso8601_timestamp(f._ts) from logs f 
                where f._t = 'timespent'
                 and f.dt = '2016-04-09'
                 and f.uid = 'd2de01a1-8f78-49ce-a065-276c0c24661b'
                 order by _ts)
  from logs d
  where _t = 'timespent'
  and dt = '2016-04-09'
  and uid = 'd2de01a1-8f78-49ce-a065-276c0c24661b'
  order by _ts;
  </code></pre>
  
  <p>This is the error I get</p>
  
  <pre><code>Query 20160411_150853_00318_fmb4r failed: line 1:61: no viable alternative at input 'SELECT'
  </code></pre>