SQL for Complete Beginners

Somebody at work just asked you for a number, and the number is trapped in a system nobody can query.

You export a file. Forty thousand rows. You filter, you scroll, you write a lookup formula that returns #N/A, and an hour later you have an answer you are not sure is right. There is a faster way, and it is one sentence long: SELECT the answer FROM your data WHERE you ask properly.

SQL for Complete Beginners takes you from "I have never written a query" to designing, testing and automating a database of your own in plain English, with no jargon, no server to install, and no assumption that you are a programmer. You will not be a programmer when you finish. You will be someone who can get the right answer out of data, every time, and prove it is right. Every query in this book was run against a real database before it was printed. The output you see is the output you get.

By the last page you will be able to: install a free database tool and ask it your first question in fifteen minutes; filter, sort, count, group and join across four tables from a blank screen; find the rows that are missing the customer who never ordered, the invoice nobody chased; change data safely, with backups, transactions and habits that prevent disasters; design your own tables from a messy spreadsheet, import the CSV, and set the rules that keep it clean; save reports as views, export them to Excel, and run them from a script on demand; read any error message as a diagnosis instead of a threat; and survive day one on someone else's system across SQLite, PostgreSQL, MySQL and SQL Server.

Then you build the capstone: a complete invoicing database clients, projects, invoices, payments designed by you from seven real business questions, tested until the numbers reconcile to the cent, and automated with a script that produces your ageing report on demand. In testing it surfaced a 291-day-old unpaid invoice worth $4,800 that nobody had chased. It will find yours.

This book is for you if you work with data but were never taught the tools: analysts-in-waiting, ops and admin staff, marketers, bookkeepers, small business owners, freelancers and career changers. It is not for you if you want database administration, stored procedures or a certification syllabus it says so on page one, and it means it.

No prior experience. No programming. No server. Just a laptop, this book, and the fifteen minutes you have been meaning to spend on this for two years.

Your data already knows the answer. This book teaches you to ask.