MAXX Function Lookup

[ronlolololo]

Hi folks, i am playing around the DAX and came across this issue. So the calculated column should return the case number of last day of the same county. It works fine for the first few rows but the stops changing after. But if I returned the date, it works prefect. Why would this happened? Please advised. Thank you!

[ryan_mayu · Accepted solution]

@ronlolololo 

please try this

Column = 
VAR _date=MAXX(FILTER('Table','Table'[countryFIPS]=EARLIER('Table'[countryFIPS])&&'Table'[State]=EARLIER('Table'[State])&&'Table'[date]<EARLIER('Table'[date])),'Table'[date])
return MAXX(FILTER('Table','Table'[countryFIPS]=EARLIER('Table'[countryFIPS])&&'Table'[State]=EARLIER('Table'[State])&&'Table'[date]=_date),'Table'[cases])

[v-kelly-msft]

Hi  @ronlolololo ,

It is because your date column is ranking ascending,so using your expression can get the result you need,but if your date column is disordering,then you will get a wrong return,such as your case number.

The best solution is to create an index column.

I made a simple sample,pls see attached.

Best Regards,
Kelly

Did I answer your question? Mark my post as a solution!

[Greg_Deckler]

@ronlolololo - Difficult to say. Please first check if your issue is a common issue listed here: https://community.powerbi.com/t5/Community-Blog/Before-You-Post-Read-This/ba-p/1116882

Also, please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490

The most important parts are:
1. Sample data as text, use the table tool in the editing bar
2. Expected output from sample data
3. Explanation in words of how to get from 1. to 2.