DAX Fridays! #54: Reverse engineer/ Deconstruct a DAX measure

[@excelisfun]

Yes, deconstructing any formula is such an important skill!!!

[@CurbalEN]

+ExcelIsFun and a great way to learn :) Happy Friday!! /Ruth

[@MrNillock]

not just an important skill... but the best way to learn how to code in general :)

[@CurbalEN]

+Collin Taylor I am a DIY too, definitely my best way of learning :) Happy Friday and say hi to your wonderful family :) /Ruth

[@dabakhbathily3359]

Whenever I come across an issue with Power BI, I watched your videos. Not only I found the answer (95%) but you always go beyond my expectation. Thanks and I meant it. Merci beaucoup.

[@CurbalEN]

Oh! Amazing feedback! thanks for taking the time to write it 😊! /Ruth

[@loganathannainar4804]

For new learners, you are demonstrating how to approach DAX formulas. Thank you and you are inspiring!!

[@CurbalEN]

+Loganathan Nainar Many Thanks for the feedback :) /Ruth

[@eddieb8337]

It's worth noting that Datediff with DAY parameter is NOT the same as using HOUR/24 (when using Datetime values). For example, if there were 2 dates, 1-Apr-2020 23:59 and 2-Apr-2020 00:01, the DAY version would return a result of 1 Day - even though only 2 minutes have elapsed - (the DAY parameter can be thought of as the number of midnights that have passed), the HOUR/24 version would return 0, as a 24 hour period has not yet elapsed. It's an important distinction.

[@saibigdata4046]

Hi great video thanks, i have requirement: Do you have any video for calculate applying filter two columns,then it will show sum of two columns.

[@CurbalEN]

Hi Sai, Not sure what you mean, can you post your question in the Power Bi Community? You can get detailed help on your case there. Thanks! /Ruth

[@vida1719]

Really great idea to deconstructing dax! Agree with Bart Titulaer that brackets could be coloured in Power BI

[@CurbalEN]

+Vida Hi Vida, there is probably an idea in the uservoice list, make sure you give it a vote or add it if it is not there. Happy weekend! /Ruth

[@ulkaulka9458]

Hi ruth , all your video's are awesome . this video I want to download, but not posted in download center.

[@xrayt2008rocket]

Nice video. Love your series!

[@CurbalEN]

+xrayt2008rocket Thanks ( for watching and the feedback) and happy Friday ;) /Ruth

[@NorbertoVeraReatigaNVR]

Super buen video!!1 Muchas gracias Ruth, como siempre nos haces fácil la comprensión del lenguaje DAX!!!. Tu canal ya esta entre mis buenos hábitos!!!

[@CurbalEN]

+Norberto Vera Reatiga Muchas Gracias a ti por apoyarme desde el principio. Un placer que aún sigas conmigo :) /Ruth

[@Bristerireland]

Hi - great video again thanks. You might consider changing the title to "Deconstruct a DAX Calculated Column". The approach you've outlined only works because the DAX expression is actually for a Calculated Column (that is added to the table), not a DAX measure (that is evaluated dynamically on a visualisation based on the filter context imposed). People who haven't yet mastered the conceptual differences between a DAX Calculated Column and a DAX Measure could become confused. Keep up the great work!!

[@CurbalEN]

+Brian Mather Hi Brian, True, the example is done with a calculated column because it is easier to visualize for the example, but the approach I use is the same for measures. The trick is to understand what “tables”/ columns are being passed to the DAX function and the way to see them for me is the same. I will do another example in the future with a measure. Thanks for the feedback I do understand what you mean :) /Ruth

[@fredrikvestin752]

Great video Ruth! This is a useful technique. Do you have any tips on how to take this a step further and also consider the row and filter context and context transition to help understand how a measure is calculated so that you can verify the result. For complex data models with inactive relationships, ambiguous relationships between tables etc. I often find it hopeless to figure out how a measure is actually calculated. If you have a database as the source you can usually write some T-SQL statements to validate the result but sometimes the data source is not that readily available. Thanks for a great channel! /Fredrik

[@josepromero1452]

Nice Video as always!! Question Ruth: When should I use a calculeted column either in Query Editor or in the data panel? Many thanks in advance!!!

[@CurbalEN]

+Josep Mussol Hi Josep, That is a great question. Let me answer it in a video so others can also be a part of it :) /Ruth

[@josepromero1452]

Of course Ruth. Great idea!! Thanks a lot

[@CurbalEN]

+Josep Mussol :)

[@barttitulaerexcelbart9400]

Hello Ruth, I agree with Brian, and of course I liked your answer that you will also do a video with a "real" measure :). In Excel the brackets are coloured, maybe in the future also for Power BI? One Question: DATEDIFF gave integers (whole numbers) as a result? In hours and Days? why was there no ROUND needed?

[@drumcorpsconcepts]

Thank you for posting these DAX videos, I find them very useful.

[@CurbalEN]

+Drum Corps Concepts Hi! Fantastic, then my goal has been fulfilled! And many thanks for taking the time to give me feedback :) Have a great weekend, /Ruth

[@MrNillock]

all your videos are SPECIAL :)

[@CurbalEN]

+Collin Taylor Thanks Collin 😊, coming from you is a real compliment! Have a great weekend :) /Ruth

[@jonmarquet]

Muy bueno Ruth, me has dado un par de ideas para solucionar algún problemilla que tengo. ¿ y para cuándo una deconstrucción de un cachopo? 😋😋😋😋😋😋😋

[@CurbalEN]

+jon marquet Ahh genial!! Cachopo a la Asturiana con queso cabrales ? ( este video no está patrocinado por la comunidad de Asturias) 😂😂😂 /Ruth

[@gagansingh3481]

Great explanation Mam 👌

[@gagansingh3481]

Ruth Mam please made more videos on complex Dax queries generally used in industries as per your experience please ....

[@mnowako]

Bravo! It's a great skill to master! Thanks Ruth!

[@CurbalEN]

+Mariusz Nowakowski Thanks! Glad you liked it :) /Ruth

[@SKRT_DATA_MUSIC]

nice mam

[@CurbalEN]

Thanks :) /Ruth