Book Image

Hands-On Business Intelligence with DAX

By : Horne
Book Image

Hands-On Business Intelligence with DAX

By: Horne

Overview of this book

Data Analysis Expressions (DAX) is known for its ability to increase efficiency by extracting new information from data that is already present in your model. With this book, you’ll learn to use DAX’s functionality and flexibility in the BI and data analytics domains. You’ll start by learning the basics of DAX, along with understanding the importance of good data models, and how to write efficient DAX formulas by using variables and formatting styles. You’ll then explore how DAX queries work with the help of examples. The book will guide you through optimizing the BI workflow by writing powerful DAX queries. Next, you’ll learn to manipulate and load data of varying complexity within Microsoft products such as Power BI, SQL Server, and Excel Power Pivot. You’ll then discover how to build and extend your data models to gain additional insights, before covering progressive DAX syntax and functions to understand complex relationships in DAX. Later, you’ll focus on important DAX functions, specifically those related to tables, date and time, filtering, and statistics. Finally, you’ll delve into advanced topics such as how the formula and storage engines work to optimize queries. By the end of this book, you’ll have gained hands-on experience in employing DAX to enhance your data models by extracting new information and gaining deeper insights.
Table of Contents (18 chapters)
1
Section 1: Introduction to DAX for the BI Pro
7
Section 2: Understanding DAX Functions and Syntax
14
Section 3: Taking DAX to the Next Level

Getting It into Context

In this chapter, we will move beyond the basics, and build upon what you learned about evaluation contexts in Chapter 1, What is DAX?.

We'll learn about evaluation contexts in more depth, including how Data Analysis Expressions (DAX) are evaluated inside a context. We'll learn about the difference between the row context and the filter context, and how these affect different DAX functions. We'll also look at how changing filters impact the evaluation of DAX functions. Finally, we'll look at some DAX functions that can change the context under which an expression is evaluated. These include the CALCULATE function, the ALL function, and the KEEPFILTERS function.

The chapter is broken up into the following sections:

  • Introducing evaluation contexts—part 2
  • Deep diving into row context
  • Deep diving into filter context
  • Changing context...