DAX - Customer first purchase

[EvertonRamone]

I need a measure wich returns me the first purchase of customers who bought product B (key product 2)

This is my data model

FactSales
KeyDate	KeyCustomer	KeyProduct	Total
1	1	1	12,9
1	2	2	13
1	3	1	156,4
1	4	1	564,8
2	1	1	894,8
2	2	1	56,5
3	1	2	564,85
3	2	3	564,8
4	1	1	1325,6
4	2	1	132,3

Customer
KeyCustomer	Name
1	Jean
2	Mari
3	Lisa
4	Julian
5	Jhonny

Calendar
KeyDate	Date
1	01/01/2018
2	02/01/2018
3	01/05/2018
4	01/08/2018

Product
KeyProduct	Product
1	A
2	B
3	C

[EvertonRamone]

@v-yuta-msft, Maybe I expressed myself wrong.

I meant I need to now every date of first purchase by customer

Customer A - 20/01/2018

Customer B - 14/01/2018

Customer C- 22/01/2018

[v-yuta-msft · Accepted solution]

Hi EvertonRamone,

Create a measure using DAX as below:

Result = 
VAR KeyDate = CALCULATE(MIN('Calendar'[KeyDate]), FILTER('Calendar', 'Calendar'[Date] = MIN('Calendar'[Date])))
VAR KeyProduct = CALCULATE(MIN('Product'[KeyProduct]), FILTER('Product', 'Product'[Product] = "B"))
RETURN
CALCULATE(MIN('Customer'[Name]), FILTER('FactSales', 'FactSales'[KeyDate]  = KeyDate && FactSales[KeyProduct] = KeyProduct))

 

Regards,

Jimmy Tao