DAX Calculations and Queries - SQL Server Analysis Services 2012 Cube Development - page 362

Chapter 10. DAX Calculations and

Queries

This chapter will expand on concepts introduced in Chapter 9 , Using Tabular Models ,
and cover these topics in greater depth:

• Combining tables using calculated columns
• Adding a calculated column
• Creating measures
• Testing a Tabular Model in Excel
• Using the CALCULATE Function
• Querying a Tabular Model

Introduction

DAX ( Data Analysis Expressions ) is actually a combination of two languages. It is
fundamentally a simple expression language, consisting of functions that work very
much like Excel functions, which return either values or objects that can be used by
other functions. Additionally, DAX is also a query language that can be used to ex-
ecute requests for a Tabular semantic model and return an entire result set for use
by a reporting tool or application to display data. DAX is an evolution of previous ex-
pression languages and those familiar with MDX and Excel functions will recognize
its heritage.

Our journey down the DAX path will begin with an introduction to the fundamental
components of DAX expressions. You will learn to use several useful functions that
can be applied to business logic and get answers to business-related questions.
Expanding on the topics introduced in the previous chapter, we will use calculated
columns to combine data from two source tables and then design calculated meas-
ures from numeric columns in the Internet Sales fact table.