Book Image

Learn MongoDB 4.x

By : Doug Bierer
Book Image

Learn MongoDB 4.x

By: Doug Bierer

Overview of this book

When it comes to managing a high volume of unstructured and non-relational datasets, MongoDB is the defacto database management system (DBMS) for DBAs and data architects. This updated book includes the latest release and covers every feature in MongoDB 4.x, while helping you get hands-on with building a MongoDB database app. You’ll get to grips with MongoDB 4.x concepts such as indexes, database design, data modeling, authentication, and aggregation. As you progress, you’ll cover tasks such as performing routine operations when developing a dynamic database-driven website. Using examples, you’ll learn how to work with queries and regular database operations. The book will not only guide you through design and implementation, but also help you monitor operations to achieve optimal performance and secure your MongoDB database systems. You’ll also be introduced to advanced techniques such as aggregation, map-reduce, complex queries, and generating ad hoc financial reports on the fly. Later, the book shows you how to work with multiple collections as well as embedded arrays and documents, before finally exploring key topics such as replication, sharding, and security using practical examples. By the end of this book, you’ll be well-versed with MongoDB 4.x and be able to perform development and administrative tasks associated with this NoSQL database.
Table of Contents (22 chapters)
1
Section 1: Essentials
5
Section 2: Building a Database-Driven Web Application
9
Section 3: Digging Deeper
13
Section 4: Replication, Sharding, and Security in a Financial Environment
14
Working with Complex Documents Across Collections

Creating a user with rights on a single database

For our first scenario, let's say that the management appoints an admin to run financial reports on the biglittle database. However, the database server also hosts another database to which this admin should not have rights. Here is an example of how the rights might be assigned:

bgReader = {
user : "bgReader",
pwd : "password",
roles : [ { role:"read", db:"biglittle" } ],
mechanisms: [ "SCRAM-SHA-256" ]
}
db.createUser(bgReader);

This user can now authenticate to the server using the mongo shell, specifying the -u and -p parameters. In addition the user needs to identify the authentication source using the --authenticationDatabase parameter. As you can see from the screenshot shown here, the new user, bgReader, can access the biglittle database and issue the findOne() command:

However, if the same user attempts to insert something into the database, the operation fails and...