Forum Discussion
Replacing values in multiple columns based on condition in Power Query
Hi, Anonymous
Based on the simulated data source and the data processing logic you provided, write the query code like this:
= Table.ReplaceValue(Source, each [day flag]="Down Day", null, (x,y,z)=> if y then z else x, List.Range(Table.ColumnNames(Source),1,4))If my code solves your problem, mark it as a solution
Hi, Anonymous
As what is suggested by ziying35 , I created data to reproduce your scenario. The pbix file is attached in the end.
Table:
You may insert a new step as below. On your side, you may add all corresponding columns in {"plan","unplan","internal","external",...}.
= Table.ReplaceValue(Source, each [day flag]="Down Day", null, (x,y,z)=> if y then z else x, List.Select(Table.ColumnNames(#"Changed Type"), each List.Contains( {"plan","unplan","internal","external"},_) ) )Result:
Best Regards
Allan
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
Hey ziying35.
I included your solution in my blogpost at https://gorilla.bi/power-query/replace-values/.
However, I'm accustomed to working with Replacer.ReplaceValues and Replacer.ReplaceText. I don't fully understand your example.
Can you elaborate on the inner workings of :
(x,y,z)=> if y then z else x?
Warm regards,
Rick
Simple understanding: the second parameter of the function Table.ReplaceValue is represented by y, the third parameter is represented by z, and the replaced element itself is represented by x
Hi ziying,
Thanks for adding the clarification. I could imagine in my head that happens. I'm just stumbled by how you thought of doing this, please help me understand.
No where does it say that Y represents the Table function, or that the third parameters should be the Z or what X should do.
If I can ask
1. How did you come up with this in the first place? Is there any documentation on this?
2. In theory, you could have replaced the function letters with any other letter, correct?
Best,
Rick
You can replace it with any string you want.
(original,logiccheck,alternative)=> if logiccheck then alternative else original
Yes, the documentation is a bit sparse on this. Here's a slight hint:
Replacer.ReplaceValue - PowerQuery M | Microsoft Docs
It's misleading, but at least it mentions parameters 🙂
I have a suspicion that this approach can be used for other M functions as well. Didn't have time to test it yet.
1. this use, I also happened to see in other places, I can not remember the place,.
2. Yes, there is nothing wrong, you can use any other letters instead
