MongoDB

Many APIs make use of a database for keeping track of the underlying data being read and written by the API. In other cases, such as IoT, the functions at endpoints may update a real object. Even when a real object or event is being tracked or triggered, it is a good idea to track the expected state in a database. A database representation can be accessed and manipulated quickly.

We won't go into depth on the use and design of a database; however, we'll briefly talk about how you could use one to extend the functionality of an API. It is rare that you will have an API that goes beyond hello world without making use of a database of some sort.

The most popular database used with Node.js is MongoDB. MongoDB is an object-oriented library with a convenient syntax for working with JSON objects. In addition to storing data as JSON-like objects, it doesn't require the use of a schema. This means that the attributes for an object can change over time without you...