To round off this book we'll look at methods in Node for storing data. No matter how powerful Express is as a web framework, it can do little without storing data somewhere. The common best practice is to store data in some sort of database. Today the range of database technology serves a wide range of use cases, from traditional SQL data warehouses to modern NoSQL document-oriented databases, to simple key/value data stores, to web-service based query services like YQL.
In this chapter we'll implement two versions of a simple Notes application. The application demonstrates CRUD (Create, Read, Update, and Delete) basics using an Express based web application, and some SQL and MongoDB modules for Node.