Monthly Archives: August 2015

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MongoDB Aggregation Framework (part 4)

6 Aug, 2015  in MongoDB  tagged aggregation / Características / Characteristics / Conceptos / Concepts / data / datos / framework / introduccion / introduction / MongoDB / pipeline / reference / sintaxis / syntax / valor / value by juanroy

This is the forth and last post of the serie about the MongoDB Aggregation Framework. We will continue with different queries. By the moment, we are going to use our five documents set inserted in our ‘aggfwktest’ collection. Average computation in a new field

> db.aggfwktest.aggregate([ ... { $group : { _id : "$user_id", mediascore : { $avg : "$score" } } } ... ]) { "_id" : 3, "mediascore" : 7 } { "_id" : 2, "mediascore" : 6 } { "_id" : 1, "mediascore" : 7.5 } >

1 2 3 4 5 6 7

> db.aggfwktest.aggregate([ ... { $group : { _id : "$user_id", mediascore : { $avg : "$score" } } } ... ]) { "_id" : 3, "mediascore" : 7 } { "_id" : 2, "mediascore" : 6 } { "_id" : 1, "mediascore" : 7.5 } >

The highest and the lowest, […]

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