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

Using operators to update contact information

In order to apply a contact information update, we use the $set update operator. As you recall, updates are performed using entity classes as an argument. Accordingly, it makes sense to use the entity class to create its own update document. Therefore, we add a method called getUpdateDoc() to the booksomeplace.entity.base.Base class, as shown here:

class Base(dict) :
def getUpdateDoc(self) :
doc = {}
for key, value in self.fields.items() :
doc.update({'$set' : {key : self[key]}})
return doc
# other methods not shown

We then add a method called edit() to that accepts a property entity as an argument. In order to perform the update, it calls the inherited getUpdateDoc() method:

    def edit(self, prop) :
query = {'propertyKey' : prop.getKey()}
return self.collection.update_one(query, prop.getUpdateDoc())