Matt Allington - Super Charge Power BI: Power BI Is Better When You Learn to Write DAX

Supercharge Power BI

Power BI is Better When You Learn to Write DAX

by

Matt Allington

Holy Macro! Books

PO Box 541731

Merritt Island, FL 32954

Supercharge Power BI

2018 Tickling Keys, Inc.

All rights reserved. No part of this book may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information or storage retrieval system without permission from the publisher. Every effort has been made to make this book as complete and accurate as possible, but no warranty or fitness is implied. The information is provided on an "as is" basis. The authors and the publisher shall have neither liability nor responsibility to any person or entity with respect to any loss or damages arising from the information contained in this book.

Author: Matt Allington

Layout: Jill Bee

Copyediting: Kitty Wilson

Cover Design: Emrul Hasan & Shannon Travise

Cover Illustration: Freepik

Indexing: Nellie Jay

Published by: Holy Macro! Books, PO Box 541731, Merritt Island FL 32954, USA

Distributed by: Independent Publishers Group, Chicago, IL

First Printing: January, 2018

ISBN: 978-1-61547-054-9 Print, 978-1-61547-237-6 PDF, 978-1-61547-360-1 ePub, 978-1-61547-131-9 Mobi

Library of Congress Control Number: 2017961952

Table of Contents

Introduction

Power BI is the latest and greatest in business intelligence (BI) software. There are so many great things about this Microsoft product that it is hard to know where to start. Perhaps one of the most important things to note about Power BI is that it is designed with business analysts and Excel users in mind. You do not need to be an IT professional to be able to use this software well.

Power BI has capabilities across four important phases of a business intelligence project:

• It has a powerful data acquisition engine that helps a user fetch and load the data needed. The underlying technology that supports data acquisition is called Power Query (accessed via the Get Data menu), and the programming language is called M.
• It has a powerful data modelling engine that allows the user to model the loaded data to make it more useful than it is in the raw state. The underlying technology that supports data modelling is called Power Pivot, and the programming language is called DAX (short for Data Analysis Expressions).
• It has a modern visualisation engine built using the latest technologies so you can build interactive reports. The Power BI visual engine has been open sourced so that anyone with the necessary skills can build new visuals to use and share within Power BI.
• Finally, it has a framework that supports multiple ways to share data with others, including a cloud-based web environment and native mobile apps. These tools make it easy to share reports and dashboards with other people who need to see and interact with the data. The tool to share Power BI reports is called the Power BI service, or PowerBI.com.

This book, Supercharge Power BI: Power BI Is Better When You Learn to Write DAX , teaches you the skills you need to use Power Pivot (the modelling tool bundled with Power BI) and the DAX language. Power Pivot brings everything that is good about enterprise-strength BI tools directly to you right inside Power BI Desktopand without the negative time and cost impacts normally associated with big-scale BI projects. In addition, it is not just the time and money that matter. The fact that you can do everything yourself directly inside Power BI is very empowering. Analyses that you would never have considered viable in the past are now can do tasks within the current business cycle.

It is worth pointing out that you can use Power BI without learning Power Pivot. However, Power BI is definitely better when you learn to write DAX. If you dont invest time in learning DAX and Power Pivot, you will be able to take advantage of only the basic capabilities of the Power BI tool. Imagine being able to use only the SUM() function in Excel. You would be able to produce only very basic and simplistic spreadsheets. Similarly, with Power BI, if you dont learn the DAX language and how the Power Pivot engine works, you will be limited to simplistic capabilities that restrict the value you can get from the tool.

There is another significant benefit to learning Power Pivot and DAX for Power BI. These skills are fully transferable to Excel. Although in this book you will be learning the DAX language using the Power BI user interface, you will be able to easily move these new skills into Power Pivot for Excel should you want to do that. And who wouldnt?

Supercharge Excel

Supercharge Power BI: Power BI Is Better When You Learn to Write DAX has been written specifically to teach Power Pivot and DAX using Power BI Desktop. I have written a sister book, Supercharge Excel: When You Learn to Write DAX for Power Pivot . These two books cover the same basic content but with a different user interface. Because the skills you will learn in this book are fully transferable to Power Pivot for Excel and vice versa, you really need only one of these books to secure the required skills. However, if you want to learn about the differences in the UI and practice what you have learnt, then reading Supercharge Excel will certainly help you cement your learning across the different UIs.

Why You Need This Book

I am a full-time Power BI consultant, trainer, and BI practitioner. I have taught many Excel users how to use Power Pivot and Power BI at live training classes, and I have helped countless others online at various Power BI forums. This teaching experience has given me great insight into how Excel users learn Power BI and what resources they need to succeed. Power BI is very learnable, but it is very different to Excel; you definitely need some structured learning if you want to be good at using this tool. I have learnt that Excel users need practice, practice, practice. The book youre reading right now, Supercharge Power BI: Power BI Is Better When You Learn to Write DAX , is designed to give you practice and to teach you how to write DAX. If you cant write DAX, you will never be good at Power BI or Power Pivot.

I refer above to Excel users , and that is quite deliberate. I have observed that Excel professionals learn DAX differently than do IT/SQL Server professionals. IT/SQL Server professionals are simply not the same as Excel business users. SQL Server professionals have a solid knowledge of database design and principles, table relationships, how to efficiently aggregate data, etc. And of course there are some Excel users who also have knowledge about those things. But I believe IT/SQL Server professionals can take a much more technical path to learning DAX than most Excel users because they have the technical grounding to build upon. Excel users need a different approach, and this book is written with them in mind. That is not to say that an IT/SQL Server professional would not get any value from this book/approach; it really depends on your learning style. But suffice it to say that if you are an Excel professional who is trying to learn DAX, this book was written with your specific needs in mind.

Incremental Learning

I am an Excel user from way backa long way back actually. Im not the kind of guy who can sit down and read a novel, but I love to buy Excel reference books and read them cover to cover. And I have learnt a lot about Excel over the years by using this approach. When I find some new concept that I love and want to try, most of the time I just remember it. But sometimes I add a sticky note to the page so I can I find it again in the future when I need it. In a way, I am incrementally learning a small number of new skills on top of the large base of skills I already have. When you incrementally learn like this, it is relatively easy to remember the detail of the new thing you just learnt.