25 Days of DAX Challenges: My Journey & Key Learnings

Ever wondered how to get better with DAX? I started 25 days challenge to push my DAX limits, and I’d love to share my experiences and the key learnings I took away from it.

 

The Setup

I found a website which has a series of DAX Challenges. Every day, there is set a different DAX question to solve, focused on various aspects of Power BI and DAX. From basic aggregate functions to complex problem-solving, the journey was enlightening. Let’s dive into my daily challenges!

 

Highlighting Some Frequently Used Functions:

1.CALCULATE():

Description: Evaluates an expression in a context altered by specific filters. Owing to its flexibility, it’s a frequent go-to.

Syntax:

CALCULATE(<expression>, <filter1>, <filter2>, …)

Example:

CALCULATE(SUM(‘Sales'[Revenue]), ‘Sales'[Category] = “Electronics”)

 

2.FILTER():

Description: Returns a table filtered based on a given condition.

Syntax:

FILTER(<table>, <expression>)

Example:

FILTER(‘Products’, ‘Products'[Price] > 100)

 

3.SUMMARIZE():

Description: Crafts a summary table detailing the desired totals across specified groups.

Syntax:

SUMMARIZE(<table>, <groupby_column1>, … , <name>, <expression>, …)

Example:

SUMMARIZE(‘Sales’, ‘Sales'[Product], “Total Revenue”, SUM(‘Sales'[Revenue]))

 

4.AVERAGE() & AVERAGEX():

Description: While AVERAGE() calculates the arithmetic mean of values, AVERAGEX() assesses an expression for each table row and then derives the average.

4.1.Syntax:

AVERAGE(<column>)

Example:

AVERAGE(‘Products'[Price])

4.2.Syntax:

AVERAGEX(<table>, <expression>)

Example:

AVERAGEX(‘Sales’, ‘Sales'[Quantity] * ‘Sales'[Price])

 

5.VAR:

Description: Enables the storage of an expression’s result as a named variable for future use in other formulas.

Syntax:

VAR <name> = <expression>

Example:

ReturnCal =

VAR AveragePrice = AVERAGE(‘Products'[Price])

RETURN

AveragePrice * 1.10

Learn More: Delving Deeper into the VAR Concept

 

Conclusion

This 25-day DAX journey was about more than just writing code. It was about understanding business problems, identifying the right metrics, and realizing the true power of DAX in business analytics.

To all aspiring DAX enthusiasts, my advice is: set challenges, get your hands dirty, make mistakes, learn, and grow. DAX is vast, but with consistent practice, you’ll be amazed at the insights you can draw from your data!

 

The Data School
Author: The Data School