Book Image

Extreme DAX

By : Michiel Rozema, Henk Vlootman
Book Image

Extreme DAX

By: Michiel Rozema, Henk Vlootman

Overview of this book

This book helps business analysts generate powerful and sophisticated analyses from their data using DAX and get the most out of Microsoft Business Intelligence tools. Extreme DAX will first teach you the principles of business intelligence, good model design, and how DAX fits into it all. Then, you’ll launch into detailed examples of DAX in real-world business scenarios such as inventory calculations, forecasting, intercompany business, and data security. At each step, senior DAX experts will walk you through the subtleties involved in working with Power BI models and common mistakes to look out for as you build advanced data aggregations. You’ll deepen your understanding of DAX functions, filters, and measures, and how and when they can be used to derive effective insights. You’ll also be provided with PBIX files for each chapter, so that you can follow along and explore in your own time.
Table of Contents (17 chapters)
Free Chapter
1
Part I: Introduction
6
Part II: Business cases
15
Other Books You May Enjoy
16
Index

How to solve the missing workdays problem

The case of the missing workdays is a not-so-exotic situation that appears to bring up rather deep issues. It can happen in any situation where you change the context to calculate something other than what's available in the original context. In other words, whenever you use CALCULATE to change context, you may run into this problem without even noticing it. As filtering and context transformation is core to working with DAX, it is a fundamental issue. And as you may have guessed, it has everything to do with AutoExist.

The root of the problem

Let's take a very close look at the context in the last datapoint in May 2020's order intake chart. We haven't included all report elements in the image, but you can guess that there are a number of filters in this context:

  • 'Calendar'[Year]: 2020
  • 'Calendar'[Month]: May
  • 'Calendar'[Workday in Month]: 21

What we would...