On Wed, Mar 24, 2010 at 03:29:36PM +0100, A. Kretschmer wrote: > In response to Louis-David Mitterrand : > > Hi, > > > > I have time series data: price(id_price int, price int, created_on > > timestamp) > > > > I'd like to select the latest price before, say, 2010-03-10 and the > > latest price after that date. > > test=*# select * from price ; > id_price | price | created_on > ----------+-------+--------------------- > 1 | 10 | 2010-01-01 00:00:00 > 1 | 12 | 2010-02-01 00:00:00 > 1 | 8 | 2010-03-01 00:00:00 > 1 | 15 | 2010-03-10 00:00:00 > 1 | 13 | 2010-03-20 00:00:00 > (5 rows) > > test=*# select * from ( > select distinct on(id_price) id_price, price, created_on from price where > created_on < '2010-02-20'::date order by id_price, created_on desc > ) foo union all select * from ( > select distinct on(id_price) id_price, price, created_on from price where > created_on > '2010-02-20'::date order by id_price, created_on asc > ) bar order by id_price,created_on ; > id_price | price | created_on > ----------+-------+--------------------- > 1 | 12 | 2010-02-01 00:00:00 > 1 | 8 | 2010-03-01 00:00:00 > (2 rows) > > That's okay for you?
Yes, that works, but I forgot in my specs (!) that I'd like the two prices (pre and post 2010-03-10) to be returned on the same row and only if a post-2010-03-10 price exists. Thanks, -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
