Re: grouping excluding some text results
От | John Sidney-Woollett |
---|---|
Тема | Re: grouping excluding some text results |
Дата | |
Msg-id | 4540ED6A.9000104@wardbrook.com обсуждение исходный текст |
Ответ на | grouping excluding some text results ("Fip" <Filippo.Bernante@gmail.com>) |
Список | pgsql-general |
Off the top of my head (and not sure how optimized)... select t1.id, t1.score, t1.description from scoretable t1, ( select id, max(score) as score from scoretable group by id ) as t2 where t1.id = t2.id and t1.score = t2.score order by t1.id If you get duplicated rows back, then try using select distinct t1.id, t1.score, t1.description ... instead. Hope that helps. John Fip wrote: > Hi, > > ho can I select some one restult for type, excluding the rest? > I have something like, as result of a join: > > | ID | score | description | > ----------------------------------------------------------------- > MG01 56 "textual description1..." > MG02 47 "another text ..." > MG02 55 "textual description, text...." <---- > note this > MG02 55 "textual description, text...." <---- > note this > MG01 35 "this is a different text...." > MG02 61 "random chars..." > (...) > > > I know that is possible selecting by grouping if I use an aggregate > function: >> select ID,max(score) by table group by ID > but I want the description too, only one description, and I have a very > large dataset, I cannot cycle with more subselections, this require too > much time; also I want to exclude duplicates: only one ID. > > What can I do? > > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org/
В списке pgsql-general по дате отправления: