Home/ Questions/Q 1093061
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-16T23:46:28+00:00

If the following is used Analytic.collection.map_reduce(map, reduce, :query => {:page => subclass_name}, :sort =>

  • 0

If the following is used

Analytic.collection.map_reduce(map, reduce, 
  :query => {:page => subclass_name}, 
  :sort => [[:pageviews, Mongo::DESCENDING]]).find.to_a

it won’t sort by pageviews. Alternatively, if it is array of hash:

Analytic.collection.map_reduce(map, reduce, 
  :query => {:page => subclass_name}, 
  :sort => [{:pageviews => Mongo::DESCENDING}]).find.to_a

it won’t work either. I think the reason it has to be an array is to specify the first field to sort by, etc. I also tried just a flat array instead of an array of array like in the first code listing up above and it didn’t work either.

Is it not working? This is the spec: http://api.mongodb.org/ruby/current/Mongo/Collection.html#map_reduce-instance_method

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    What are you trying to do? Sort is really only useful in conjunction with limit: it’s applied before the map so you can just MapReduce the latest 20 items or something. If you’re trying to sort the results, you can just do a normal sort on the output collection.

    • 0