Introduction

In Chapter 1, Understanding and Describing Data, we discussed analytics and how we can use data to obtain valuable information. While we could, in theory, analyze all data by hand, computers are far better at the task and are certainly the preferred tool for storing, organizing, and processing data. Among the most critical of these data tools is the relational database and the language used to access it, Structured Query Language (SQL). These two technologies have been cornerstones of data processing and continue to be the data backbone of most companies that deal with substantial amounts of data.

Companies use SQL as the primary method for storing much of their data. Furthermore, companies now take much of this data and put it into specialized databases called data warehouses and data lakes so that they can perform advanced analytics on their data. Virtually all of these data warehouses and data lakes are accessed using SQL. We'll be looking at working with SQL...