Useful SQL

Hey there! Thanks for taking the time to check out the contents of this page. I thought I'd start with a brief origins story behind this book.

Who am I and what have I learned so far?

I've spent the better part of a decade writing SQL - initially as part of my academics and then as a Data Analyst, Product Analyst and Analytics Engineer at several companies. In this time SQL has managed to fight off competition from all directions to retain its place as the de facto language for getting answers from data.

As organisations have invested more in data the desire to have quick access to answers hidden away in databases is at an all time high. Unfortunately, there is a technical barrier and more often than not data teams turn into gatekeepers of what should be easy to access data for everyone. The reason? SQL is still largely privy to folks in data teams.

BI tools like Tableau and Looker have helped lower this barrier to entry but they are not bulletproof solutions. I've seen data teams turn into bottlenecks for eager stakeholders way too often now and trust me when I say that's the last thing anyone wants.

Why did I write this book?

Over the years I've had several stakeholders try and balance this knowledge asymmetry by trying to learn SQL. They often ask me if SQL is easy to learn. My answer is "it's worth the investment". How easy it is depends on the individual, but the ROI is massive not just for the stakeholders but for the entire team. This means better and more timely decisions, which should mean better products.

If this book helps moves the needle on this even by a fraction of an inch it would have served its purpose.

There are a million resources out there to learn SQL. What makes this book any different?

This book challenges status-quo techniques for learning SQL. Many resources out there are geared toward data analysts and engineers who need to know database principles at a much deeper level.

This book doesn’t get into any of that. Everything you need to know is delivered in just 50 pages and should take only around 20 hours to complete.

The idea is to teach the 20% of SQL needed to answer 80% of questions without requiring help from data analysts. The best way to do this is to play the role of different stakeholders at a fictitious startup where your data analysts are always busy. I hope that this gamified approach makes learning SQL a lot more fun!

Who is this book for?

Aspiring data professionals hoping to go from zero to one can use this as a great jump off point, but the folks who would get the most value out of this book are data stakeholders who want to supercharge their access to insights.

What can I expect to find in this book?

Each chapter has a handful of SQL questions and a couple of bonus questions. The queries get progressively harder but never too hard. The focus here is to cut through excessive theory and dive into answering questions about a product/business using SQL.

Table of Contents

• Introduction
• Getting Started
• Scenario
• Chapter 1: Basic SELECT statements
• Chapter 2: Grouping
• Chapter 3: Intro to Table Joins
• Chapter 4: INNER Joins
• Chapter 5: LEFT Joins
• Chapter 6: Joining More than Two Tables
• Chapter 7: Conditional Statements
• Chapter 8: Date Functions
• Chapter 9: Common Table Expressions
• Solutions

Want to read a sample first?

You can find a sample chapter on this Notion link.