Get Previous column value

[perner123]

I am very new to PBI Desktop and currently fighting something which should be quite simple.

I tried to calculate a new measure "PrevValue" which should include the "Value" of the previous month.
The DAX expressions i tried:

1. PrevValue = CALCULATE(SUM(PERST[Value]);PARALLELPERIOD('INV V_DIM_DATE'[FULLDATE].[Date];-1;MONTH))
   returns the Value of the same Period
   
2. PrevValue = CALCULATE(SUM(PERST[Value]);PREVIOUSMONTH('INV V_DIM_DATE'[FULLDATE].[Date]))
   returns an empty value

Ideally it should always show the difference between the value of the current & previous period, even if the user doesn't select all periods in a row.

I have no clue, why even showing the previous value doesn't work. Is there any simple thing I am missing?

So the result should look like this (PrevValue 0 in first period, as no previous period available)

thanks in advance

[amitchandak]

Check this

https://community.powerbi.com/t5/Desktop/DAX-getting-previous-value/td-p/489921

But if need this year vs last year. try these formula

Year Sales = CALCULATE(TOTALYTD(sum(Sales[Sales Amount]),('Date'[Date Filer])))
Last Year Sales = CALCULATE(TOTALYTD(sum(Sales[Sales Amount]),dateadd('Date'[Date Filer].-12,month)))


Year  = CALCULATE(SUM(table[column]),DATESYTD(endofmonth(dateadd('Date'[Date Filer],-1,MONTH))))
Last Year  = CALCULATE(SUM(table[column]),DATESYTD(endofmonth(dateadd('Date'[Date Filer],-13,MONTH))))


Year Sales = CALCULATE(TOTALYTD(sum(Sales[Sales Amount]),endofmonth(dateadd('Date'[Date Filer].-1,month))))
Last Year Sales = CALCULATE(TOTALYTD(sum(Sales[Sales Amount]),endofmonth(dateadd('Date'[Date Filer].-13,month))))

Appreciate your Kudos. In case, this is the solution you are looking for, mark it as the Solution. In case it does not help, please provide additional information and mark me with @
Thanks.

My Recent Blog - https://community.powerbi.com/t5/Community-Blog/Comparing-Data-Across-Date-Ranges/ba-p/823601

[parry2k · Accepted solution]

@perner123 few things:

- make your INV V_DIM_DATE as date table

- remove .[date] from your measures.

[perner123]

Thanks a lot! After changing both things you mentioned, it works fine!
Initially i struggeled creating the table as date table, as there was a "dummy-element" included and i received the message "date table cannot have gaps". So i just excluded this element and everything worked fine.

[parry2k]

@perner123 here is a post on how to mark you table as date table.