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)
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

Introducing table functions

In Chapter 6, Progressive DAX Syntax and Functions, we looked at the two types of functions found in the DAX language: scalar functions and table functions. We saw that table functions are functions that, when evaluated, return a table of data. Unlike scalar functions, which return a single value, table functions cannot directly be used to define a measure or a calculated column. Instead, they are used in conjunction with functions that accept a table expression as one of their parameters.

DAX table functions can be used for the following purposes:

  • In a DAX expression that is used to define a calculated table (this excludes Excel Power Pivot, which currently does not support calculated tables).
  • In the definition of a DAX function, where the function accepts a table expression as a parameter.
  • To query a tabular data model using Excel or SQL Server Management...