Book Image

Hands-On Business Intelligence with DAX

By : Ian Horne
Book Image

Hands-On Business Intelligence with DAX

By: Ian 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)
Section 1: Introduction to DAX for the BI Pro
Section 2: Understanding DAX Functions and Syntax
Section 3: Taking DAX to the Next Level

Breaking down DAX syntax

So far, we've looked at quite a few examples of DAX expressions, but we haven't looked in detail at the structure of a typical DAX expression.

Let's set that straight by breaking down a typical DAX expression. For this one, we will define a measure that will give us the total sum of values in the Sales Quantity column of the Sales table, for products in the Deluxe class:

1 Deluxe Sales Quantity
2 =
4 (
5 [Sum of Sales Quantity Measure]
6 ,
7 'Product'[Class]
8 = "Deluxe"
9 )

This DAX expression can be broken down as follows:

  1. We start with the name we want to give to the measure, which in this case is Deluxe Sales Quantity.
  2. The equals sign operator (=) defines the start of the DAX formula. When writing DAX expressions with Excel Power Pivot and SSAS Tabular, the equals sign will have a colon before it (:=).
  3. Our measure...