Forum Discussion

Yamabushi's avatar
Yamabushi
Helper I
2 years ago

Help understanding this DAX

Hi,   I wish to understand this measure, especially the part in AND(): 30 Day Total Sales = CALCULATE(     [Total Sales],     AND(         DimDate[FullDateAlternateKey] > MAX(DimDate[Ful...
DAX
bhanu_gautam's avatar
bhanu_gautam
Super User
2 years ago

Yamabushi  Please find the summary

  1. MAX(DimDate[FullDateAlternateKey]): This part finds the maximum (latest) date in the DimDate table.

  2. MAX(DimDate[FullDateAlternateKey]) - 2: Subtracting 2 days from the latest date gives you a date that is 2 days ago.

  3. DimDate[FullDateAlternateKey] > MAX(DimDate[FullDateAlternateKey]) - 2: This condition filters dates that are greater than 2 days ago.

  4. DimDate[FullDateAlternateKey] <= MAX(DimDate[FullDateAlternateKey]): This condition filters dates up to the latest date.

  5. AND(...): The AND function combines the two conditions, ensuring that the date is within the last 2 days.

  6. CALCULATE([Total Sales], ...): Finally, the CALCULATE function applies these date filters to the [Total Sales] measure, giving you the total sales for the last 2 days

And accept as solutin if it helps

Yamabushi's avatar
Yamabushi
Helper I
2 years ago

Hi,

 

thank you, @bhanu, but that was not what I was asking. I understand what each function individually does. My question specifically relates to evaluation context:

  • Why is DimDate[FullDateAlternateKey] in MAX evaluated in the original evaluation context?
  • Why is DimDate[FullDateAlternateKey] on the left side of the comparison operator evaluated in the evaluation context coming from CALCULATE?
  • In formulas like this, how do we know when something is evaluated in a modified evaluation context, and when something is being evaluated in the original evaluation context?

Thanks!