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Posted to user@couchdb.apache.org by He Shiming <he...@gmail.com> on 2011/02/25 04:51:13 UTC
Design question, article with logs of comments and ratings
Hi,
I've got a design question. The scenario is: the database stores a
series of articles, and each article can be commented and rated.
For articles, naturally I'll have {"_id": "article-id", "type":
"article" ...} . And each article is a single document in the
database.
I'm not sure what form should I use to put ratings and comments. I
would like to keep a history of rating and comments for each article,
but still be able to calculate average rating easily. I may also need
"likes" and "dislikes" for each of the comment. So it'll be sorted in
a custom order.
How do I design documents to store such information? Thanks!
--
Best regards,
He Shiming
Re: Design question, article with logs of comments and ratings
Posted by Simon Metson <si...@googlemail.com>.
Also the "Joins Redux" on http://blog.couchone.com/post/446015664/whats-new-in-apache-couchdb-0-11-part-two-views is handy, probably does what you want for comments...
Sent with Sparrow
On Saturday, 26 February 2011 at 04:32, Aravinda VK wrote:
This might help.
> http://www.cmlenz.net/archives/2007/10/couchdb-joins
>
> On Sat, Feb 26, 2011 at 7:46 AM, He Shiming <he...@gmail.com> wrote:
>
> > On Fri, Feb 25, 2011 at 9:25 PM, Simon Metson
> > <si...@googlemail.com> wrote:
> > > And query it for a specific article with
> > http://localhost:5984/voting/_design/vote/_view/vote?group=true&key=%22foo%22
> > >
> > > Mike Miller did a nice summary of how you could do time binned data for
> > your historical info (using the timestamp field in the vote doc) on
> > http://nosqltapes.com/video/understanding-mapreduce-with-mike-miller
> > >
> > > HTH
> > > Cheers
> > > Simon
> >
> > So each comment and rating is a single document. And grouping should
> > be used to reduce. Thank you very much Simon. I got the idea now.
> >
> > --
> > Best regards,
> > He Shiming
>
>
>
> --
> Regards
> Aravinda | ಅರವಿಂದ
> http://aravindavk.in
>
Re: Design question, article with logs of comments and ratings
Posted by Aravinda VK <ha...@gmail.com>.
This might help.
http://www.cmlenz.net/archives/2007/10/couchdb-joins
On Sat, Feb 26, 2011 at 7:46 AM, He Shiming <he...@gmail.com> wrote:
> On Fri, Feb 25, 2011 at 9:25 PM, Simon Metson
> <si...@googlemail.com> wrote:
> > And query it for a specific article with
> >
> >
> http://localhost:5984/voting/_design/vote/_view/vote?group=true&key=%22foo%22
> >
> > Mike Miller did a nice summary of how you could do time binned data for
> your historical info (using the timestamp field in the vote doc) on
> http://nosqltapes.com/video/understanding-mapreduce-with-mike-miller
> >
> > HTH
> > Cheers
> > Simon
>
> So each comment and rating is a single document. And grouping should
> be used to reduce. Thank you very much Simon. I got the idea now.
>
> --
> Best regards,
> He Shiming
>
--
Regards
Aravinda | ಅರವಿಂದ
http://aravindavk.in
Re: Design question, article with logs of comments and ratings
Posted by He Shiming <he...@gmail.com>.
On Fri, Feb 25, 2011 at 9:25 PM, Simon Metson
<si...@googlemail.com> wrote:
> And query it for a specific article with
>
> http://localhost:5984/voting/_design/vote/_view/vote?group=true&key=%22foo%22
>
> Mike Miller did a nice summary of how you could do time binned data for your historical info (using the timestamp field in the vote doc) on http://nosqltapes.com/video/understanding-mapreduce-with-mike-miller
>
> HTH
> Cheers
> Simon
So each comment and rating is a single document. And grouping should
be used to reduce. Thank you very much Simon. I got the idea now.
--
Best regards,
He Shiming
Re: Design question, article with logs of comments and ratings
Posted by Simon Metson <si...@googlemail.com>.
Hi,
Let's say you have a +1 or -1 vote for a given document. You could record this with a document like:
{
"article" : "article-id", "vote": 1, "timestamp": now()
}
or
{
"article" : "article-id", "vote": -1, "timestamp": now()
}
(where now() is some function you run client side to get the time.
You'd then be able to get the rating via a simple map function and a _sum reduce:
function(doc) {
if (doc.vote) emit(doc.article, doc.vote);
}
And query it for a specific article with
http://localhost:5984/voting/_design/vote/_view/vote?group=true&key=%22foo%22
Mike Miller did a nice summary of how you could do time binned data for your historical info (using the timestamp field in the vote doc) on http://nosqltapes.com/video/understanding-mapreduce-with-mike-miller
HTH
Cheers
Simon
On 25 Feb 2011, at 03:51, He Shiming wrote:
> Hi,
>
> I've got a design question. The scenario is: the database stores a
> series of articles, and each article can be commented and rated.
>
> For articles, naturally I'll have {"_id": "article-id", "type":
> "article" ...} . And each article is a single document in the
> database.
>
> I'm not sure what form should I use to put ratings and comments. I
> would like to keep a history of rating and comments for each article,
> but still be able to calculate average rating easily. I may also need
> "likes" and "dislikes" for each of the comment. So it'll be sorted in
> a custom order.
>
> How do I design documents to store such information? Thanks!
>
> --
> Best regards,
> He Shiming