If you’re new to Power Query, then this book might not be the best choice for you. There are books out there that introduce the basics through the user interface and simple button-based actions, offering a straightforward way to get started.

On the other hand, if you are serious about fully understanding the M language, then this book is for you. If this is your first experience with M, you may find certain concepts challenging. Reading through the pages the first time will provide you with lots of information, but some topics may be too complex. As you become more familiar with M, reading the book again will likely make these complex topics easier to understand.

Overall, our goal was to write a book that blends theoretical knowledge with practical examples. The first few chapters are more theoretical and provide the M language fundamentals. As the book progresses and your understanding deepens, we include projects and exercise files for you to work along with.

The Power Query M language is useful for a variety of users. Power BI users may use M to prepare their data model, Excel users may transform data and output it on their spreadsheets, while data factory users could use M to query an API and transfer the result into a database. In this book, we aim to cater to all these different audiences.

Although some subjects, such as creating custom connectors or optimizing performance, may appeal more to those with advanced knowledge due to their technical nature, we believe it’s beneficial for all users to understand the different ways the M language can be used.

Starting with the M language can be daunting, and mastering it took us several years. It’s a challenging journey that requires focus and a lot of experimentation. However, if you persevere, our book offers unprecedented depth of all aspects of M, allowing you to become a true M expert.