Book Image

MongoDB Cookbook - Second Edition - Second Edition

By : Amol Nayak
Book Image

MongoDB Cookbook - Second Edition - Second Edition

By: Amol Nayak

Overview of this book

MongoDB is a high-performance and feature-rich NoSQL database that forms the backbone of the systems that power many different organizations – it’s easy to see why it’s the most popular NoSQL database on the market. Packed with many features that have become essential for many different types of software professionals and incredibly easy to use, this cookbook contains many solutions to the everyday challenges of MongoDB, as well as guidance on effective techniques to extend your skills and capabilities. This book starts with how to initialize the server in three different modes with various configurations. You will then be introduced to programming language drivers in both Java and Python. A new feature in MongoDB 3 is that you can connect to a single node using Python, set to make MongoDB even more popular with anyone working with Python. You will then learn a range of further topics including advanced query operations, monitoring and backup using MMS, as well as some very useful administration recipes including SCRAM-SHA-1 Authentication. Beyond that, you will also find recipes on cloud deployment, including guidance on how to work with Docker containers alongside MongoDB, integrating the database with Hadoop, and tips for improving developer productivity. Created as both an accessible tutorial and an easy to use resource, on hand whenever you need to solve a problem, MongoDB Cookbook will help you handle everything from administration to automation with MongoDB more effectively than ever before.
Table of Contents (17 chapters)
MongoDB Cookbook Second Edition
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Implementing aggregation in Mongo using a Java client


The intention of this recipe is not to explain aggregation but to show you how aggregation can be implemented using the Java client from a Java program. In this recipe, we will aggregate the data based on the state names and get the top five state names by the number of documents that they appear in. We will use the $project, $group, $sort, and $limit operators for the process.

Getting ready

The test class used for this recipe is com.packtpub.mongo.cookbook.MongoAggregationTest. To execute the aggregation operations, we need to have a server up and running. A simple single node is what we need. Refer to the Installing single node MongoDB recipe from Chapter 1, Installing and Starting the Server for instructions on how to start the server. The data that we will operate on needs to be imported in the database. The steps to import the data are given in the Creating test data recipe in Chapter 2, Command-line Operations and Indexes. The next...