Preface

Over the last decade, the popularity of the Power Query’s M language has continuously grown, such that it has become nearly ubiquitous within the Microsoft ecosystem, including Power BI, Excel, Power Platform, Dynamics 365, SQL Server, and Data Factory. Today, M and Power Query are indispensable tools for modern data professionals, such as business analysts, data scientists, and data enthusiasts.

This book seeks to make you a master of the M language. While M can be written using the Power Query Editor’s graphical user interface (GUI), this approach severely limits you to only a small fraction of the 700+ core M functions. We estimate that the GUI for authoring M queries allows you to solve only about 50% of challenges related to data transformation. However, mastery of M allows you to bring that figure close to 100%. Starting with simple concepts and code, this book progressively moves you along a path of increasing complexity. Complex concepts are explained in clear and concise language with practical examples that demonstrate the concepts in action. By the end of this book, there will be few, if any, data transformation challenges that you won’t be able to tackle head-on.

Get ready for an exciting and rewarding journey toward your mastery of the M language!