DAX Measure

[Anonymous]

Hi,

I'm having some trouble coming up with a measure. I have a report that I refresh with new data at the beginning of each month. This new data contains changes to the old daata and new information for the previous month. IE. It's currently August 1st - so I'll replace the data with a new table that contains July data as well as changes to other months data. There will be no data relating to the current month I'm in.

I'm trying to set up a matrix to show the data as of June 31st compared to the data as of July 31st. The columns are the measures as follows: Data as of June 31st, Data as of July 31st, difference between the two, percent difference. 

To show the data as of June 31st I have a measure written as: 

Previous Month = CALCULATE ([Count of Units], DATEADD(DimDate[Date],-1,MONTH))

However, 

This measure gives me the same amount of units as my current month measure

Count of units= COUNTX(unitData,unitData[unitCount ]) which is just the total amount of units.

Am I interpreting this wrong and is there another DAX measure I should be using?

Thanks

[Anonymous]

I've been instead using this formula to calculate the prior months total units?

Previous Month Total = CALCULATE(

[Count of Units]

,FILTER(

ALL('DimDate'[Month_Nbr])

, DimDate[Month_Nbr] <= MAX(DimDate[Month_Nbr] ) - 1))

[daxer-almighty]

You have to have a relationship defined between the tables. It looks like currently you don't. Hence the filter under CALCULATE has no effect on the calculation.

[Anonymous]

All of the tables in this report are related. I am also using a Date Dimension table which is where the filter is pointing to.