mongodb aggregation examples

Mongodb advanced 2: mongodb aggregation and mongodb advanced AggregationIn the previous article we talked about mongodb's advanced query: http://blog.csdn.net/stronglyh/article/details/46817789 This article introduces mongodb aggregation. I. mongodb

/*** MongoDB $type operator*/ /*** The $type operator is based on the Bson type to retrieve the matching data type in the collection and returns the result.* The types of MongoDB that can be used are shown in the following table:* Type Number Notes*

The recent new project to use MySQL, while not yet forgotten, summarizes the following MongoDB aggregations.aggregation refers to the various operations that can handle batch records and return results. MongoDB provides rich aggregation operations

in the two previous articles the basic aggregation function of data aggregation in MongoDB count, distinct, group > and the MapReduce of data aggregation in MongoDB >, we've provided two implementations for data aggregation, and today, in this

MongoDB cluster building (master-slave replication, replica and) (5), mongodb master-slaveVi. Architecture ManagementMongodb master-slave clusters are divided into two types:1: master-Slave replication (master-Slave) -- The Slave server will not

The blog has moved Https://www.tianmingxing.com MongoDB is an open-source, document-oriented NoSQL (not only SQL) database written using C + +, and one of the most popular NoSQL databases. NoSQL Introduction NoSQL means "Not just SQL", is the

In the previous article we talked about MongoDB advanced query: http://blog.csdn.net/stronglyh/article/details/46817789This article is about MongoDB aggregation.A: MongoDB has a lot of aggregation framework, so that the transformation and

Always think that the aggregation in MongoDB is the aggregation pipeline, today saw the introduction of the official website to have more understanding. The role of aggregation: Put multiple records together, and then get a single result through a

First, IntroductionMongoDB's aggregation framework, which is used primarily to transform and combine the documents in a collection to make use of the data for analysis.The basic idea of the aggregation framework is:Multiple artifacts are used to

March 25 MongoDB (taken from "Humongous") 1.4 release shortly after its founder Dwight Merriman (formerly DoubleClick Ceo/cto) announced 10gen--open source document database MongoDB behind the company, It will provide business training and