On May 16, 2016, at 20:48 , David G. Johnston <
david.g.johnston@gmail.com> wrote:
On Monday, May 16, 2016, Guyren Howe <
guyren@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" 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.
