Calculate days between created date and the first purchase

[Anonymous]

hi everyone,

Hope anyone can help, I get trouble when facing this issue:

I have 2 tables:

Dim_Customer ([CusID],[OpenDate])

fSales ([PurcharseDate],[CusID])

Connect by [CusID]

I want to calulate average number of days between Open Date and The first Purchase date of a group of Customer, 
Can anyone help me how can I calculate it.
Thank you so much

[Anonymous]

oh so sorry, I didn't descript my issue clearly,

@amitchandak I followed your solution but it has another problem:
I try this DAX:

--

Avg days =
VAR A = AVERAGEX(

VALUES(Dim_Customer[CusID]),

datediff(min(Dim_Customer[OpenDate]), min(fSales[PurcharseDate]),day)+1)

VAR _result = CALCULATE(A, fSales[Status] <> "con1" && "con2")

RETURN _result 

--

there are some customers haven't had purchase yet (so their min(fSales[PurcharseDate]) is null) and some cases the OpenDate is after first PurcharseDate (because of special condition of my company), I want to calculate customers who has OpenDate <= the first PurchaseDate only.
How could it be?

Thank you

[Anonymous]

@amitchandak 

Thank you so much, I applied succesfully in my case!

[amitchandak · Accepted solution]

@Anonymous , Try a new

avergageX(values(Dim_Customer[CusID]), datediff(min(Dim_Customer[OpenDate]), min(fSales[PurcharseDate]),day))