Calculating total Amount of Internet Sales (AdventureWorks data) MDX

Question

How can I count the total number of sales in the "FactInternetSales" table for the selected member of the DATES hierarchy?

(
[Order Date].[DATES].CURRENTMEMBER, 
COUNT(DISTINCT([Fact Internet Sales].[Sales Order Number].[Sales Order Number]
)

this is what I have at the moment however it doesn't work :/

Answer 1

Try count on the outside with extra braces to indicate a set of tuples:

COUNT(
  {  
    [Order Date].[DATES].CURRENTMEMBER
    *
    [Fact Internet Sales].[Sales Order Number].[Sales Order Number]
  }
)