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

Summary

In this chapter, we took a more in-depth look at evaluation contexts, focusing on the two different types of evaluation contexts: row context and filter context.

First, we took a detailed look at the row context, learning how this applies when you create a calculated column or use a function that iterates through the rows of a table. We followed this with a detailed look at the filter context, learning about the different sources of filters, and how these can affect the results coming back from a DAX expression. Then, we learned about the concept of expanded tables, and how these can help you to understand how filters can propagate through related tables. Finally, we looked at how you can change a context in DAX. We learned how you can change a row context into a filter context, and how you change filter context with the CALCULATE function.

In the next chapter, we will...