1. Cross UG Summit EMEA 2017 8/6/2018 7:24 PM
© 2017 Dynamic Communities. All rights reserved.

2. DAX 101 for Power BI Belinda Allen Microsoft MVP
8/6/2018 7:24 PM
DAX 101 for Power BI
Belinda Allen
Microsoft MVP
Business Intelligence Program Manager

3. Back of my Surface Book

4. Me…
Business Intelligence Program Manager (aka BA Nut) – PowerGP Njevity, Inc.
Microsoft MVP – Business Solutions
GPUG All-Star
Advisor – Association of Dynamics Professionals Credentialing Council
Board of Advisors for PBIUG
Author: 2 books
Belinda Allen

5. Single Function Code Data Analysis eXpressions
What is DAX?
Data Analysis eXpressions
Functional Language used by
Microsoft Power BI, PowerPivot
And SSAS Tabular
Single Function Code

6. DAX
Excel
MDX
TSQL

7. Aggregate - Defined

8. Iterate - Defined

9. M Language
Simple Math
Text Fields
Everything Else

10. What can be created with DAX?
Calculated Columns
Calculated at refresh time, result stored in data
Calculates using the current row, not a specific row
Calculated Measures
Great for values that we do not want to be performed on a row by row basis or have them aggregated.
Code stored with data, calculated with visual

11. Syntax Notes:
Total Sale = ‘Sales’[Quantity] * ‘Sales’[Unit Price]
Table name in single quotes (if spaces or characters exist)
Column name in square brackets
*Always use the table name with the field! It makes it easier to read later.

12. Data Type Handling (Operator Overloading)
Operators are NOT strongly typed
The result depends on the inputs
Operator Overloading kills speed
Know your data type
Adding 2 strings
“5” + “4” = 9
Concatenate 2 strings
5 & 4 = “54”

13. Calculated Columns and Measures Demo

14. Column syntax vs. Measure syntax
Gross Margin Percent =
‘Sales’[Gross Margin] /
‘Sales’[Sales Amount]
Measure:
Gross Margin Percent Measure =
SUM(‘Sales’[Gross Margin]) /
SUM(‘Sales’[Sales Amount])
Creates
Gross Margin
For each Row
Creates
Gross Margin
For Totals

15. When to use Column or Measure
Need to slice or filter on value
Calculate percentages or ratios
Need complex aggregations
Consumes
Memory
Consumes
CPU

16. Demo – Calculated Column
Dynamics GP Tech Conference
8/6/2018 7:24 PM
Demo – Calculated Column

17. Add Column Demo
Current Row
Single Quote
Query Name

18. Demo – Calculated Measure
Dynamics GP Tech Conference
8/6/2018 7:24 PM
Demo – Calculated Measure

19. Calculated Columns vs. Measures
Need to slice value
Need to filter value
Consumes Memory / Space
Measure
Calculate %’s
Calculate Ratios
Consumes CPU
Complex Aggregations

20. Dynamics GP Tech Conference
8/6/2018 7:24 PM
Aggregate Functions
SUM
MIN
MAX
AVERAGE
Aggregate Functions with Iterations
SUMX
MINX
MAXX
AVERAGEX

21. Count Functions
COUNT (only for numeric columns)
COUNTA (counts all rows EXCEPT blanks)
COUNTBLANK (counts only blanks)
COUNTROWS (counts rows in table)
DISTINCTCOUNT (counts unique fields)

22. AND (&&)* OR (||)* NOT (!)* IF IFERROR Booleon Logical Functions
*Can use C# Operators

23. Information Functions
ISBLANK
ISNUMBER
ISTEXT
ISNONTEXT
ISERROR

24. MAX and MIN Functions to compare values
Computes the maximum of Extended Price
= MAX('Sales Line Items'[Extended Price])
Measure
Column
Computes the maximum between Gross Margin and Cost
=MAX('Sales’[Extended Cost], 'Sales'[Gross Margin])

25. DIVIDE Function IF ( Sales[Sales Amount] <> 0,
Sales[Gross Margin] / Sales[Sales Amount], 0)
DIVIDE (
Sales[Gross Margin],
Sales[Sales Amount],

26. Math, Text & Date Functions
Many similar Excel functions

27. Using fields from different Queries - Demo

28. Related Functions RELATED RELATEDTABLE
Uses the Many side to grab a row from the one side in a Many to One relationship.
Commission = ‘Sales’[SalesAmount] * RELATED(‘Salesperson’[CommRate])
RELATEDTABLE
Uses the One side to grab an aggregate from the many side in a One to Many relationship
NumberOfSales = COUNTROWS(RELATEDTABLE(‘Sales’))
Sales = SUMX(RELATEDTABLE(‘Sales’), ‘Sales’[Quantity] * ‘Sales’[UnitPrice])

29. Tables Functions
FILTER
ALL
VALUES
DISTINCT
RELATEDTABLE

30. Declaring and using Variables
Corrected Quantity:=
VAR
TotalQuantity = SUM(Sales[Quantity])
RETURN (
IF (
TotalQuantity > 1000,
TotalQuantity * .95,
TotalQuantity * 1.25 )

31. Q&A Ballen@Njevity.com
Dynamics GP Tech Conference
8/6/2018 7:24 PM
Q&A