Reduce Mongodb Map Lessons

Question

Possible duplicate:
How to use Map / Reduce in MongoDB?

I saw a MongoDb presentation for a new aggregation framework. There is a presentation, progressive examples, etc.

Do you know something like this for map / reduce in MongoDB?

I have not found ...

Answer 1

Check the mongodb cookbook , you can see many examples of map reduction with good explanations.

Also check out my answer to other questions in the mongo map section for more details.

Answer 2

: MongoDB

Answer 3

Check the map reduction documentation for MongoDB. You will find many examples there.

The general form for mapReducethis is:

db.collection.mapReduce(
  <mapfunction>,
  <reducefunction>,
  {
      out: <collection>,
      query: <document>,
      sort: <document>,
      limit: <number>,
      finalize: <function>,
      scope: <document>,
      jsMode: <boolean>,
      verbose: <boolean>
  }
);