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

Summary

In this chapter, you have learned how to use helper tables to capture user input. Depending on your intended use, a helper table can be as simple as a few rows with options, or a larger list based on other data in the Power BI model. In most cases, helper tables have no relationships with other tables in the model. User input in the form of a selection in a slicer can be captured in DAX measures. The SWITCH function is used to select the appropriate calculation based on the user input.

Keep in mind that when using multiple helper tables for dynamic selections, it is better to use an extended SWITCH statement than to work with nested SWITCH functions. Be aware that nesting can also occur through calling another measure that does its own SWITCH. Piling up dynamic selectors like this can eventually lead to performance issues.

In the next chapter, we dive deeper into calendar-based analysis. While we have used several time-intelligence DAX functions in this chapter, many...