The goal of the course is to demonstrate all the features of DAX, providing the knowledge to write formulas for common and advanced business scenarios. Students will use DAX to solve real world scenarios that enhance reporting capabilities.
While DAX can be used across a variety of applications, this course will be taught using Power BI.
This 2 day course includes columns and measures, context transition, variables and optimization.
Have you been using DAX for a while? Are you drowning in Youtube videos? Tired of copying DAX expressions that you don’t understand? This training is aimed at Power BI, Power Pivot for Excel and Analysis Services developers who wish to gain a better understanding of DAX and the context behind it. Discover some of the lesser-known DAX functions, explore the different behaviours of similar functions (and discuss when to use each) and master your understanding of CALCULATE.
Before attending this course you must:
- have experience with Power BI equivalent to that covered in Power BI Essential Skills
- understand reporting data models in Power BI, Excel PowerPivot or SSASS Tabular Model
- have a basic understanding of DAX functions and syntax (ie able to use SUM, CALCULATE, or IF functions to create calculated columns and measures)
Upon completion of this course, students will:
- Create complex calculated measures to further extend the reporting capabilities of the Power BI data model
- Understand the context of the DAX language and how it works within the report’s data model
- Demonstrate proper use of the CALCULATE function and how it behaves
- Use table functions to dynamically filter measures
- Understand the properties of a Date table and use it to create time intelligence measures
- Know what to look out for when using DAX in reporting
Module 1: Introduction to DAX
A review of DAX and its most basic functions; SUM, MIN, MAX. In this module, you will get familiar with the dataset that we will be using throughout the course and learn a few tricks for keeping your DAX code easy to read.
What is DAX?
Common DAX Functions
Unit Price Analysis
Module 2: Columns vs Measures
Learn the differences between calculated columns and measures, where to use each, when they are calculated, and how they are impacted by slicers and filters in your report. Learn how to leverage relationships in your data model to create calculated columns using data from multiple tables.
Implicit vs Explicit Measures
Using measures and columns
Sale Type by City
Module 3: Introduction to Evaluation Contexts
Now that you understand columns vs measures, start to debunk the concept of Evaluation Contexts in DAX and understand why measures behave the way they do.
Introduction to evaluation contexts
Module 4: Introduction to CALCULATE
CALCULATE is a powerful DAX function that is often misunderstood. Learn the basic syntax of CALCULATE and use it to calculate ratios.
Introduction to CALCULATE
Ratios and Percentages
Module 5: Context Transition
In this module, we will continue working with the CALCULATE function and explore its power of context transition. Learn what this means for your calculated columns.
Introduction to Context transition
Automatic CALCULATE in measures
Equivalent Filter context
Manipulating Evaluations Contexts
Module 6: Working with Iterators
Iterators create a virtual calculated column. This can help reduce the amount of DAX you need to write to get your desired result. In this module, we’ll explore common iterators and see the importance of understanding that evaluation context when working with these virtual calculated columns.
Introduction to Iterators
Sales per Working Day
Module 7: Table Filter Functions
Now that you’re familiar with Iterators, we can leverage the power of table filter functions to narrow in on exactly the information we need.
Introduction to Table Functions
VALUES, DISTINCT Functions
Ranking Stores by Profit
Finding above average Customers
Module 8: Evaluation contexts and Relationships
Building the right data model is crucial to the success of any report. Learn how DAX uses the relationships in your data model to calculate the results.
Advanced evaluation contexts
Row context and relationships
Filter context and relationships
Filtering many columns
Total Shipments vs Total Orders
Module 9: Variables
Variables can help keep your DAX code tidy and optimized, but more importantly they can provide context transition within measures. In this module, we will learn how variables are calculated and when to use them.
Calculation of variables
Variables for optimization
Variables for context transition
EARLIER function vs variables
First purchase amount
Module 10: Date Table
Having a robust date table is key to any time intelligence calculations. Learn the few simple steps you need to take to ensure your time intelligence functions calculate properly.
Date table properties
CALENDAR vs CALENDARAUTO vs import
Mark as Date Table
Set sorting options
Module 11: Time Intelligence
Don’t break out the calculator just yet- DAX time intelligence functions enable you to easily make comparisons for Year on Year, Month on Month, Year to Date, 12 Month Rolling average and more. In this module, we will learn the formula for success with DAX time intelligence.
Introduction to Time Intelligence
Common Time Intelligence Functions
Time Intelligence DAX formula for success
Year to Date Sales Percent Change (from previous year)
Rolling 12 Month Average
Module 12: Optimization
Now that know all the common DAX functions and their evaluation contexts, how do you optimize your code? In this module, we will look at some tools for determining the performance of your DAX as well as some tips to help improve that performance.
Percent growth calculated two ways