DAX: How can I exclude user ids found in one measure from the other measure?

[iplaygod]

Hi!

I am doing stats on sales. And I have a table containing sales and user ids.
I want to enforce a rule that excludes any User IDs found in measure 1 from measure 2.

table looks something like this:

Date        User ID    Product     Discount
---------------------------------------------------------
2018-11-01    1    shoe A        yes
2018-11-02    1    shoe B        no
2018-11-03    1    shoe C        yes
2018-11-04    2    shoe A        no
2018-11-05    3    shoe A        no
2018-11-06    4    shoe A        yes
2018-11-07    5    shoe A        yes
2018-11-08    6    shoe A        no
2018-11-09    7    shoe A        yes
2018-11-10    8    shoe A        no

I want to count distinct user ids found during a certain period.

I want to create 2 measures:

[Users purchased with discount]

and

[Users purchased without discount]

However, the problem is that in some cases, users appear in both.
User ID = 1 has purchased both WITH and WITHOUT a discount.

And so this user will be counted in both measures.
And if I add the two measures together, the total number of users will be inflated, because one user will count in both.
I want to enforce a rule that excludes any User IDs found in measure 1 from measure 2.

I think I should be able to do this by extracting the user ids from measure 1 and then using a NOT IN clause in measure two.

But currently I have no idea how to actually achieve this.

Please give me some example code.

Thanks!!

[LivioLanzo · Accepted solution]

Try like this: 

CALCULATE(
    DISTINCTCOUNT( Sales[User ID] ),
    Sales[ Discount] = "no",
    NOT Sales[User ID] IN 
        CALCULATETABLE( VALUES( Sales[User ID] ), Sales[ Discount] = "yes" )
)

[iplaygod]

thanks @LivioLanzo for quick reply!
I will try it and get back!