Chapter 1. Spring Mongo Integration

MongoDB is a popular NoSQL database and is a document-based one too. It is written using the popular and powerful C++ language, which makes it a document-oriented database. Queries are also document-based, and it also provides indexing using JSON style to store and retrieve data. MongoDB works on the concept of collection and documentation.

Let's look at few terminology differences between MySQL and MongoDB:

MySQL	MongoDB
Table	Collection
Row	Document
Column	Field
Joins	Embedded documents linking

In MongoDB, a collection is a set or a group of documents. It is the same as RDBMS tables.

In this chapter, we shall start by setting up a MongoDB NoSQL database and will integrate a spring application with MongoDB to perform CRUD operations. The first example demonstrates updating single document values. The second example considers an order use case where it requires two document references to be stored in the collection. It demonstrates the flexibility in referencing different documents of MongoDB using objectId references.

We need to go for a NoSQL database only if the applications have heavy write operations. MongoDB also suits the cloud environment very well, where we can take copies of databases easily.

In the next section, we shall see how we can get started with MongoDB, beginning with installing it, using the Spring Framework, and integrating MongoDB. To get started, we shall show basic Create, Retrieve, Update, and Delete (CRUD) operations with various use cases.