The combination of PHP, MySQL, and Linus has been very popular among open-source web developers for almost 20 years now. I used this powerful combination around 2000, and later moved on to .net, Oracle, and SQL server due to the changes of jobs. Fast forward 13 years, around 2013, one of my friends decided to jump on the wagon of PHP and MySQL from .net shop. He said there were more remote opportunities in PHP and MySQL world, and there were latest features such as MVC pattern and objects in PHP as well.
The book begins with introductory text on PHP and MySQL, and builds a simple website using MVC pattern. Then the content is divided into two threads. The first thread dives deep into mastering PHP. It covers functions, objects, etc. The second thread focuses on MySQL programming including basic database design concepts. These two threads then merges into the most exciting final chapters in my opinion, real-world e-commerce website embedded a content / image management sub-system.
I think this book covers more than enough topics on both PHP and MySQL to kick start your learning experience if you just begin. You should follow along the examples in the book and do the exercises. The learning experience is quite rewarding because we are going to learn the following systems and tooling, PHP / MySQL (of course), NetBean IDE, Xdebug, XAMPP Control Panel, MySQL work bench, etc. For more experienced developers, this book can be a desktop reference or a fun read. I highly recommend this book.