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From Fabio Batalha <fabiobata...@gmail.com>
Subject Re: Doubts with start and end keys + descending=true
Date Thu, 16 Dec 2010 12:39:59 GMT
Ok now I understand.

It's working now.

Do you know a better place to read and learn those tricks. I didn't found
any issue about the flip in the wiki and in the book couchdb definitive
guide.

Many thanks
Fabio Batalha

On Thu, Dec 16, 2010 at 10:27 AM, Sebastian Cohnen <
sebastiancohnen@googlemail.com> wrote:

> Unless I missed something you didn't flip the startkey/endkey parameters
> again. You need to do this, since couch is not sorting the result but
> reading the index backwards.
>
> So if you want to have your results for your query
> ?startkey=[%22arg%22,{}]&endkey=[%22arg%22] descending, you have to flip the
> paramters like this:
> ?startkey=[%22arg%22]&endkey=[%22arg%22,{}]&descending=true
>
> On 16.12.2010, at 13:20, Fabio Batalha Cunha dos Santos wrote:
>
> > Yes,
> >
> > This issue was understood.
> >
> > But when I want just a single key the flit did not take effect once the
> > startkey is the same of the endkey.
> >
> > For example:
> >
> > These are my keys.
> >
> > "key":["arg","20101000"]
> > "key":["arg","20101000"]
> > "key":["arg","20101100"]
> > "key":["arg","20101100"]
> > "key":["scl","20101000"]
> > "key":["scl","20101000"]
> > "key":["scl","20101100"]
> >
> > I want to get only the key="arg" so my query is:
> > ?startkey=[%22arg%22,{}]&endkey=[%22arg%22]
> > For this query the result is:
> > "key":["arg","20101000"]
> > "key":["arg","20101000"]
> > "key":["arg","20101100"]
> > "key":["arg","20101100"]
> >
> > That's perfect.
> >
> > Now I want to enable the descending true expecting the result
> > bellow.The idea is to bring at first the most recent registers because
> > the second parameter is ISO DATE.So my query is:
> >  ?startkey=[%22arg%22,{}]&endkey=[%22arg%22]&descending=true
> >
> > "key":["arg","20101100"]
> > "key":["arg","20101100"]
> > "key":["arg","20101000"]
> > "key":["arg","20101000"]
> >
> > Instead of this result I have a empty list.
> >
> > Thanks,
> > *Fabio Batalha C. Santos*
> > Colegiado SciELO
> > www.scielo.org
> > FAPESP - CNPq - BIREME - FapUNIFESP
> >
> >
> >
> > On Wed, Dec 15, 2010 at 7:49 PM, Nils Breunese <N.Breunese@vpro.nl>
> wrote:
> >
> >> You quite literally need to flip your startkey and endkey, so you'll
> need
> >> to query with
> ?startkey=[%22arg%22,{}]&endkey=[%22mex%22]&descending=true
> >>
> >> Nils.
> >> ________________________________________
> >> Van: Fabio Batalha Cunha dos Santos [fabio.batalha@scielo.org]
> >> Verzonden: woensdag 15 december 2010 21:24
> >> Aan: user@couchdb.apache.org
> >> Onderwerp: Re: Doubts with start and end keys + descending=true
> >>
> >> Now the descending parameter is working but I'm still not having the
> >> expected result.
> >>
> >> For example:
> >>
> >> 1. Results from arg to mex in ascending mode.
> >>
> >>
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22arg%22]&endkey=[%22mex%22,{}]
> <
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22arg%22]&endkey=[%22mex%22,%7B%7D]
> >
> >>
> >> the result have arg,chl and mex keys. That's ok!
> >>
> >> 2. Now flipping. Results from mex to arg in descending mode.
> >>
> >>
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22mex%22]&endkey=[%22arg%22,{}]&descending=true
> <
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22mex%22]&endkey=[%22arg%22,%7B%7D]&descending=true
> >
> >>
> >> the result have only keys = "chl". That isn't ok, I was expecting mex,
> chl
> >> and arg in the descending mode.
> >>
> >> Other Example:
> >>
> >> 1. Results with keys = arg
> >>
> >>
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22arg%22]&endkey=[%22arg%22,{}]
> <
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22arg%22]&endkey=[%22arg%22,%7B%7D]
> >
> >>
> >> the result is a list with key = arg. That's ok!
> >>
> >>
> >>
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22arg%22]&endkey=[%22arg%22,{}]&descending=true
> <
> http://fabiobatalha.couchone.com/scieloorg/_design/couchdb/_view/article_date?startkey=[%22arg%22]&endkey=[%22arg%22,%7B%7D]&descending=true
> >
> >>
> >> In this example I can't just flip the key values once I'm filtering only
> >> one
> >> key value "arg"
> >> the result is a empty list with. That isn't ok, I was expecting a
> key="arg"
> >> list in the descending mode
> >>
> >> Thanks,
> >> *Fabio Batalha C. Santos*
> >> Colegiado SciELO
> >> www.scielo.org
> >> FAPESP - CNPq - BIREME - FapUNIFESP
> >>
> >>
> >>
> >> On Wed, Dec 15, 2010 at 5:08 PM, Matthew Woodward <
> matt@mattwoodward.com
> >>> wrote:
> >>
> >>> On Wed, Dec 15, 2010 at 10:58 AM, Sebastian Cohnen <
> >>> sebastiancohnen@googlemail.com> wrote:
> >>>
> >>>> try to flip startkey/endkey when discending=true :)
> >>>>
> >>>
> >>> Yep, ran into this just yesterday and that was indeed the trick.
> >>> --
> >>> Matthew Woodward
> >>> matt@mattwoodward.com
> >>> http://blog.mattwoodward.com
> >>> identi.ca / Twitter: @mpwoodward
> >>>
> >>> Please do not send me proprietary file formats such as Word,
> PowerPoint,
> >>> etc. as attachments.
> >>> http://www.gnu.org/philosophy/no-word-attachments.html
> >>>
> >> ------------------------------------------------------------------------
> >> VPRO   www.vpro.nl
> >> ------------------------------------------------------------------------
> >>
>
>

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