In response to Louis-David Mitterrand :
> Hi,
>
> I have a simple table
>
> price(id_product, price, date)
>
> which records price changes for each id_product. Each time a price
> changes a new tuple is created.
>
> What is the best way to select only the latest price of each id_product?
There are several ways to do that, for instance with DISTINCT ON (only
postgresql):
test=*# select * from price ;id_product | price | datum
------------+-------+------------ 1 | 10 | 2009-09-01 1 | 12 | 2009-09-10 2 | 11 |
2009-09-10 2 | 8 | 2009-09-13
(4 rows)
test=*# select distinct on (id_product) id_product, price from price order by id_product, datum desc;id_product |
price
------------+------- 1 | 12 2 | 8
(2 rows)
Andreas
--
Andreas Kretschmer
Kontakt: Heynitz: 035242/47150, D1: 0160/7141639 (mehr: -> Header)