When are variables evaluated in DAX

Learn how DAX evaluates variables, which is important to avoid common mistakes when using DAX for the first time.

[ZiggyBoon]

First of all: First!! Secondly, LEARNING that it's possible to create variables within an iterative calculation is very useful! I learn something from every SQLBI video I watch!

[druthorah]

"Why variables are not named constants?" "Nobody knows" 😂

[gvitullib]

Great video. I thought I knew enough details about variables in DAX, but after watching this video, it's clear to me that there is always something more to learn.

[sameerdeshpande]

Thanks Alberto. Never knew could define and call variables in nested format!

[pranaydhanvijay]

i find it very informative, it helps to understand the concept of variables

[nevermore]

newbie to DAX, and this video is very helpful. please do more, i'm watching all of your videos. Tks Sir !

[TRZMac]

Hey Alberto,

Thank you for this great video, as always, it was very informative and helpful!

I wanted to ask if you could do a video about VAR in row context and how it replaces the EARLIER() function. I kind of understand how this works, but the concept is still a little vague to me. I would appreciate such a video a lot! ❤

Thanks a ton!

[LouLouMagou]

This is gold, thank you so much Alberto!

[NMC-elto]

very nicely explained Sir, Thanks a lot....Sir,

[kaselchirman]

This was very insightful, thank you Alberto

[thegreatlobu]

At 17:40 wouldn't moving the AverageSales inside the iterator make it so that it calculates the average sales for that customer and not all customers?

[mwaltercpa]

Thanks Alberto, I like at 11:00 when you demo using the same nested var name Result to show that the inner hides the outer. Didn’t know that. Can you tell me if there is another benefit beyond showing the separate evaluation of the two? or as you said, to stick w the same return naming pattern? Thanks!

[GaryThomann-CoGC]

14:30 good point, variables (VAR) are constants

[TopnutritionCl]

when i had that scenario i avoided the variables, because they gave me the wrong result. now i understand better how to use them

[Ahmed-ewe]

Thanks Alberto
I ve a simple question, does using variables a good thing in terms of optimization and speed?


Thanks

[jyrrin]

Just curious: in Python, you can constantly redeclare a variable's constant within a block (if it's initialized as a constant). I know you could technically just replace the variable's value wherever it's declared in the DAX, but if for whatever reason I wanted to redeclare the variable (say 'VAR Discount = 0.85' on one line and then 'VAR Discount = 0.75'), would the second declaration override the first declaration in the same manner it would in Python?

Thanks in advance!

[dineshs]

The value of variables will be constant when used in calculated columns also ?
I am using a column in my calculated column variable

[drkamikaze]

Would it also be possible to use variables to create summarytable with filters and then apply rank on items in the sunmary table? I can't modify upstream data so all work has to be done with Power Query or Dax. I had somewhat limited success with calculated columns but cant apply a filter to a RANK

[HebertAG]

So for time intelligence like SAMEPERIODLASTYEAR or DATEADD we should use the measure always instead of the Variable?

[MrSparkefrostie]

I am very interested in how and why you would use error in the real world