Create colum with the difference of two rows

[JoaoMS]

Hi all,

I've been trying to figure out how to create a new column in Power Query in order to calculate the difference between two values of some columns. Every day we get data of Accumulated Operating Hours of some equipments, and we need to know the daily operating hours. As seen in the next table, we have a base line of data and it grows every day.

			To create	To create
Date	Motor 1 Acc.	Motor 2 Acc.	Motor 1 Day	Motor 2 Day
28/04/2023	15,400	8,752	-	-
29/04/2023	15,424	8,764	24	12
30/04/2023	15,428	8,785	4	21

Thanks in advance,

Joao 

[Ashish_Mathur]

Hi,

Will there be a row for each day (without anyday being missed)?  While this can be done using Power Query, the solution would be difficult to author if there are many Motors i.e. columns because one will have to create a calculated column for each motor.  How many motor columns do you have?

[JoaoMS]

Hi @Ashish_Mathur , indeed, everyday the table will increase one row with data of at least 12 motors. So we'll need to create 12 new columns with the daily operating hours.

Thanks,

[Ashish_Mathur]

So that is then a convincing reason to not do it in the Query Editor because you will have to create those columns manually.  You should do this via a measure directly in the visual.

[JoaoMS]

Hi @Ashish_Mathur , so you mean that it is more complicated to create these new columns in Power Query, because what we currently do is manually calculate these data in the source excel file, and then in Power Query we treat the data (unpivot and pivot) in order to get the following table and then easily create some visualizations:

Date	Motor	Daily Hour	Acc. Hours
28/04/2023	Motor 1	-	15,400
28/04/2023	Motor 2	-	8,752
29/04/2023	Motor 1	24	15,424
29/04/2023	Motor 2	12	8,764
30/04/2023	Motor 1	4	15,428
30/04/2023	Motor 2	21	8,785

Thanks,

Joao

[Ashish_Mathur]

Hi,

I would not suggest writing those custom column formulas in the Query Editor.  After unpivoting the raw dataset, we can write DAX measures to calculate the hours of each day.  If you need further help, then share the data with information of 10 motors (columns).

[JoaoMS]

Hi @Ashish_Mathur  please find lines below the link of the spreasheet commented:

https://docs.google.com/spreadsheets/d/1NjQr7d10b-iQxUHnZm7Hc-xauk46yR-i/edit?usp=drive_link&ouid=11...

Thanks,

Joao

[Ashish_Mathur · Accepted solution]

Hi,

You may download my PBI file.

Hope this helps.

[vicky_]

motor 1 day = 
var previousValue = CALCULATE(max('Table'[m1]), FILTER('Table', 'Table'[date] < EARLIER('Table'[date])))
return IF(previousValue > 0, 'Table'[m1] - previousValue)

Try this formula.

[JoaoMS]

Hi, it works fine for DAX, however we need to create these columns in Power Query because after that we need to do some unpivot and pivot actions.

Thanks.