Forum Discussion
TopN based on Measure instead of Column
Hi everyone, I am struggling with the TopN function and I hope you can help me out.
Data: event registration data, with calculated columns for CY (current year) and LY (Last year). I also created a measure to show the count difference between them, “CY-LY Reg Diff”
Goal: create a card that displays the region and store type with the largest deficits year-on-year (smallest value for “CY-LY Diff” measure)
Challenge: I have tried this formula, but it gives me “blank” as a region.
Largest Deficit Region = CALCULATE(SELECTEDVALUE('Sample Data'[Region]),TOPN(1,'Sample Data',[CY - LY Reg Diff],ASC))
| Year | Store Type | Region | Registered | Last year | Current year |
| Year 1 | Store Type A | West | 1 | 1 | 0 |
| Year 1 | Store Type C | South | 1 | 1 | 0 |
| Year 1 | Store Type C | Midwest | 1 | 1 | 0 |
| Year 1 | Store Type B | West | 1 | 1 | 0 |
| Year 1 | Store Type B | West | 1 | 1 | 0 |
| Year 1 | Store Type B | West | 1 | 1 | 0 |
| Year 2 | Store Type C | West | 1 | 0 | 1 |
| Year 2 | Store Type B | Midwest | 1 | 0 | 1 |
| Year 2 | Store Type B | South | 1 | 0 | 1 |
| Year 2 | Store Type C | Midwest | 1 | 0 | 1 |
Any help or tips would be greatly appreciated.
Thank you.
This piece of code:
Largest Deficit Region = CALCULATE( SELECTEDVALUE('Sample Data'[Region]), TOPN(1, 'Sample Data', [CY - LY Reg Diff], ASC ) )returns BLANK because SELECTEDVALUE returns BLANK when there is more than 1 region returned.
Change the expression under CALCULATE to show the number of regions - distinctcount( 'sample data'[region] ) - and you'll see it's not 1.
Please read this: https://dax.guide/topn/
Best
D
4 Replies
Could you use ADDCOLUMNS to add your TOPN column and then take the MIN or MAX of it?
Hi, I must be doing something wrong here. I added ADDCOLUMNS to the expression, but now it looks like it's using it as multiple columns- I thought that I only added one. 😞
= CALCULATE( SELECTEDVALUE('Sample Data'[Region]), ADDCOLUMNS('Sample Data',"Top N",TOPN(1,'Sample Data',[CY - LY Reg Diff],ASC)))Error message: "The expression referrs to multiple columns. Multiple columns cannot be converted to a scalar value."I must be missing a step or three.This piece of code:
Largest Deficit Region = CALCULATE( SELECTEDVALUE('Sample Data'[Region]), TOPN(1, 'Sample Data', [CY - LY Reg Diff], ASC ) )returns BLANK because SELECTEDVALUE returns BLANK when there is more than 1 region returned.
Change the expression under CALCULATE to show the number of regions - distinctcount( 'sample data'[region] ) - and you'll see it's not 1.
Please read this: https://dax.guide/topn/
Best
D
