Introduction
The first edition of this book set out to explain data analysis from an eminently practical perspective, using the familiar tools of SQL and Excel. The guiding principle of the book was to start with questions and guide the reader through the solutions, both from a business perspective and a technical perspective. This approach proved to be quite successful.
Much has changed in the ten years since I started writing the first edition. The tools themselves have changed. In those days, Excel did not have a Ribbon, for instance. And, window functions were rare in databases. The world that analysts inhabit has also changed, with tools such as Python and R and NoSQL databases becoming more common. However, relational databases are still in widespread use, and SQL is, if anything, even more relevant today as technology spreads through businesses big and small. Excel still seems to be the reporting and presentation tool of choice for many business users. Big data is no longer...