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

Calculated columns

A calculated column is a column of data that is added to a table in the Power BI model by performing a DAX calculation. A basic example is to calculate the value of a sales transaction by multiplying the number of products sold by the price per product (note that column names are written between square brackets in DAX):

    Amount = [Quantity] * [Price]

Below is the resulting calculated column:

Figure 1.3.1: A calculated column

Calculated columns are a straightforward way to add some intelligence to the Power BI model. If you come from an Excel background, this probably has the most natural feel to it, as putting formulas in columns is the way most Excel users have learned to work in Excel. But our strong recommendation is: DO NOT use calculated columns, unless you have very good reasons to do so. There are a couple of reasons why:

  • A calculated column creates new data, which takes up space in the model. As was discussed in the previous...