Almost all the applications you write will handle external data of some kind. In this part, you’ll learn how to store, retrieve, and manipulate data through streams and databases.
In chapter 4, you’ll start by building two console applications that read files and folders. Then you’ll learn to read and write JSON. Those tasks will give you the skills to make HTTP requests to web services, which you’ll practice against a popular website. Working with external data is slow and can often be parallelized, so chapter 4 will give you a first taste of asynchronous programming.
Chapter 5 will get you working with relational databases. You’ll use the powerful Entity Framework Core (EF Core) library to retrieve and manipulate data in a real SQL database. Building on this fundamental skill, you’ll create a web service with create, retrieve, update, and delete (CRUD) functionality. Then you’ll use Swagger to allow others to ingest your service.