Question

I need to get three fields from a table. The table has the fields – id, timestamp, viewTime. I need to get the min(timestamp), max(timestamp), viewTime of the record with max(timestamp). I would rather have only one query.

SELECT MAX(timestamp), 
       MIN(timestamp), 
       viewTime 
  FROM session_progress 
 WHERE session_id = 2374;

This query return the min, max correctly, but returns the minimum viewTime. WHat I really want is the viewTime of the record that has the maximum timestamp.

Ex:

  timestamp             viewTime 
  ----------------------------------
  2011-11-05 10:21:00          1055
  2011-11-06 15:00:00          8900
  2011-11-07 18:20:00           750
  2011-11-07 19:23:00          4200

The query returns viewTime 750, but I need the viewTime of the max, which is 4200.

If the answer is written in grails, even better (this is same as the SQL query above):

def sp_res = sp.get {
            projections {
                min("timestamp")
                max("timestamp")
                totalTime
            }
            and {
                eq("sessionId", unSession.id)
            }
        }

Answer 1

select b.maxT, b.minT, viewTime 
from session_progress,

(select max(timestamp) as maxT, min(timestamp) as minT
from session_progress 
where session_id=2374 ) b

where where session_id=2374 AND timestamp = b.maxT

Thats just as idea, I have not tested it though. Pardon any bugs.