Dax not working

Hi homelander123 

Thank you very much Fowmy for your prompt reply.

This is the principle of slicers. When you select a month in a slicer, it will only show data relevant to your selection.

I recommend you create a date table as a slicer, but be careful not to create a relationship between the date table and the original table.

Here's some dummy data

"Query1"

Create a Date table.

Date = 
SELECTCOLUMNS(
    'Query1',
    "Date",
    'Query1'[SetupDate],
    "Year",
    'Query1'[SetupDate].[Year],
    "Month",
    'Query1'[SetupDate].[MonthNo]
)

Select Year and Month from the Date table as slicers.

Create a measure.

PreviousMonthCount = 
VAR SelectYear = SELECTEDVALUE('Date'[Year])
VAR SelectMonth = SELECTEDVALUE('Date'[Month])
VAR PreviousMonthDate = EOMONTH(DATE(SelectYear, SelectMonth, 1), -1)
RETURN
CALCULATE(
    SUM(Query1[NewCount]),
    FILTER(
        ALL('Query1'),
        MONTH('Query1'[SetupDate]) = MONTH(PreviousMonthDate)
        &&
        YEAR('Query1'[SetupDate]) = YEAR(PreviousMonthDate)
        &&
        'Query1'[SetupDate] <= PreviousMonthDate
    )
)

Here is the result.

Regards,

Nono Chen

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