Power BI(DAX)- Create measure to count distinct rows filtered by condition

Question

I have below Customer Transactions data. In a month, customer may buy one or multiple times data pack ,or may not buy data pack.

Irrespective of how many times data purchased in a month by a customer. I'm trying to find number of months that each customer purchased the data.

Total Subscribed Months is expected column.

Since customer may buy Data Subscribed (GB) more than once in a month. First I'm calculating Total Data Purchased in a month by customer.

Total Data Purchased = CALCULATE(
                    SUM('Customer Transactions'[Data Subscribed (GB)]),
                        ALLEXCEPT('Customer Transactions','Customer Transactions'[Account Number],'Customer Transactions'[Date])
    )

Second, Calculate number of months customer purchased the data pack.

Total Subscribed Months = 
CALCULATE(
            DISTINCTCOUNT('Customer Transactions'[Account Number] ),
            'Customer Transactions'[Total Data Purchased]>0
            )

But its not working. Please advise how to correct formulae ?

Answer 1

Assuming your table looks like this:

Account Number	CUSTOMER_TYPE	Data Subscribed(GB)	Free Data	Date	Total Subscribed Months
10001	Retail	250	0	01 October 2019	1
10001	Retail	0	100	01 November 2019	1
10002	Retail	200	0	01 October 2019	1
10002	Retail	250	0	01 November 2019	2
10003	Retail	300	0	01 October 2019	2
10003	Retail	0	0	01 October 2019	2
10003	Retail	100	0	01 October 2019	2
10003	Retail	100	0	01 November 2019	2
10003	Retail	100	0	01 November 2019	2
10003	Retail	0	0	01 December 2019	2

DAX Calculations

Total Subscribed Months

Total Subscribed Months = 
CALCULATE (
    DISTINCTCOUNT ( 'Customer Transactions'[Date] ),
    FILTER ( ALL ( 'Customer Transactions'[Data Subscribed(GB)] ), [Data Subscribed(GB)] > 0 )
)

Total Data Purchased

Total Data Purchased = 
    SUM('Customer Transactions'[Data Subscribed(GB)])

Output

Table visual with Account Number, Total Subscribed Months and Total Data Purchased.