How to Group mongodb - mapReduce output?

Question

i have a query regarding the mapReduce framework in mongodb, so i have a result of key value pair from mapReduce function , now i want to run the query on this output of map

Answer 1

You could try to group the output data after mapreduce to every 5 interval count through aggregate like below

db.data.aggregate([
    { "$group": {
        "_id": {
            "$subtract": [
                { "$subtract": [ "$value.count", 0 ] },
                { "$mod": [ 
                    { "$subtract": [ "$value.count", 0 ] },
                    5
                ]}
            ]
        },
        "count": { "$sum": 1 }
    }}
])

Also maybe here is one related question here.