Part VI: SQL and Object Relational Mapping

In this part of the book we're going to cover something that doesn't quite fit into the rest of the book's structure, but is a very necessary topic for junior developers to understand. Knowing how to structure data into a SQL database will teach you how to think logically about your data storage requirements. There's a long established method for deconstructing data, storing it efficiently, and accessing it. In recent years the development of NoSQL databases has made this different, but the basic concepts behind Relational Database Design are still useful. Everywhere that you need to store data there's a need to structure it well and understand it.

Most of these exercises will involve you using a SQL database, so I recommend you download the sqlite3 binary from the SQLite3 download database to work with if you do not already have it. We are using Python so this is already installed with most Python installations, but sometimes it is not available. If you can't run this Python code in your python shell:

>>> import sqlite3

Then your python is not installed with sqlite3 by default. You'll need to find out why it's missing, and most likely there's another package you have to install before you can use it inside Python.