On May 16, 2016, at 20:48 , David G. Johnston <david.g.johns...@gmail.com> wrote: > > On Monday, May 16, 2016, Guyren Howe <guy...@gmail.com > <mailto:guy...@gmail.com>> wrote: > I have this SELECT clause as part of a larger query: > FIRST_VALUE(drs.id) OVER (PARTITION BY drs.order_ID ORDER BY drs.position > ASC) AS current_drs_id > Seems reasonable to me: group and sort the fields in this table and give me > the first value. > > But I get "column "drs.id <http://drs.id/>" must appear in the GROUP BY > clause or be used in an aggregate function". > > Huh? > > The larger query would help…
SELECT o.id, os.status AS status, o.status_updated_at, o.should_hold_at_airlines, (SELECT drs2.id FROM delivery_route_segments drs2 WHERE drs2.order_id = o.id AND NOT drs2.completed ORDER BY drs2.position LIMIT 1) AS current_drs_id, FROM orders o JOIN order_statuses os ON (o.status = os.id) JOIN delivery_route_segments drs ON (drs.order_id = o.id) JOIN pick_up_addresses pua ON (pua.order_id = o.id) GROUP BY o.id, os.status I would prefer to do the subquery as a window function, both because that is cleaner to read and also because I believe it is likely to be more efficient.
