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Date: Mon, 23 Nov 2009 19:54:03 +0100
Message-ID: <622cacf50911231054p1c807c59q3be53d57c7f45d7f@mail.gmail.com>
Subject: Re: How to get nested-key-sorted collection of documents
From: Szymon Kapeniak <szymon.kapeniak@gmail.com>
To: user@couchdb.apache.org
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Thank you both, it helps a lot. I'll try this approach soon.
One question I have is in which version of couchdb group_level was introduc=
ed?
I currently work on 0.8...

2009/11/23 Brian Candler <B.Candler@pobox.com>:
> On Mon, Nov 23, 2009 at 08:58:04AM +1100, Mark Hammond wrote:
>> Here your map function looks something like:
>>
>> emit([doc.author, doc.date], null);
>>
>> Your rows will then be returned, with the _id, in order of author and
>> date. =A0You could query like:
>>
>> startkey=3D["Tolstoj", 1985], endkey=3D["Tolstoj", 1999]
>>
>> To query a range of dates for a single author.
> ...
>> Very similar:
>>
>> emit([doc.author, doc.date, doc.publisher], null);
>>
>> By using the group_level capability (see the wiki about the view API),
>> you could still search just by author, by author and date, or by all 3
>> fields.
>
> And of course you could use this view for the first query as well. A quer=
y
> for
>
> =A0startkey=3D["Tolstoj"]&endkey=3D["Tolstoj", {}]
>
> will still find all the relevant rows - it's just that this time they wil=
l
> be sorted by publisher and then _id, rather than just _id.
>
> If you have a reduce function (e.g. which counts books), then using
> group_level=3D2 would give you counts by author and year, independent of
> publisher.
>