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)
Section 1: Essentials
Section 2: Building a Database-Driven Web Application
Section 3: Digging Deeper
Section 4: Replication, Sharding, and Security in a Financial Environment
Working with Complex Documents Across Collections

Other important expression operators

Here is a brief summary of other important pipeline expression operators:

Category Operator Notes
Arithmetic $add, $subtract, $multiply, $divide, and $round
Performs the associated arithmetic operation to returns sums of numbers, and so on. Note that $add and $subtract also work on dates. It should be noted that $round is only available as of MongoDB 4.2.
Array $arrayElemAt, $first, and $last
Returns the array element at a specified index or the first/last elements. $first and $last were introduced in MongoDB 4.4.
$arrayToObject and $objectToArray Converts between an array and object.
$in Returns a Boolean value: TRUE if the item is in the array and FALSE otherwise.
$map Applies an expression to every array element.
$filter Returns a subset of array items matching the filter.
Boolean $and, $or, and $not Lets you create complex expressions.
Comparison $eq, $gt, $gte, $lt, $lte, $ne, and...