Book Image

MongoDB 4 Quick Start Guide

By : Doug Bierer
Book Image

MongoDB 4 Quick Start Guide

By: Doug Bierer

Overview of this book

MongoDB has grown to become the de facto NoSQL database with millions of users, from small start-ups to Fortune 500 companies. It can solve problems that are considered difficult, if not impossible, for aging RDBMS technologies. Written for version 4 of MongoDB, this book is the easiest way to get started with MongoDB. You will start by getting a MongoDB installation up and running in a safe and secure manner. You will learn how to perform mission-critical create, read, update, and delete operations, and set up database security. You will also learn about advanced features of MongoDB such as the aggregation pipeline, replication, and sharding. You will learn how to build a simple web application that uses MongoDB to respond to AJAX queries, and see how to make use of the MongoDB programming language driver for PHP. The examples incorporate new features available in MongoDB version 4 where appropriate.
Table of Contents (11 chapters)

Using the aggregation pipeline

The MongoDB aggregation pipeline framework consists of the aggregate() collection method, and a sequence of operations referred to as stages ( This sequence is referred to as a pipeline.

For illustration, let's assume that there's a collection called purchases, where each purchase has an amount of information as well as embedded customer and product objects:

We wish to generate a report on the total sales for each customer from Australia. A simple db.collection.find() command will not suffice as it is incapable of grouping the customers. The problem is further compounded by the fact that country information is embedded in the customer object within each purchase. In order to generate this report, we will first need to address stages.