Count occurence per ID and per type

[eaj]

In my dataset I have some products that consists of a base fee and then the custommer pays extra per extra item. 

The invoice data are available in a table as follow:

#Invoice	Main_Item	Base_fee_included
1	ItemA	Yes
2	ItemB	No
3	ItemA	No
3	ItemA	No
4	ItemA	Yes
4	ItemB	No

I want to count the numbers of missing base fees (there can only be one base fee per item and invoice. I started with this messure: 

MissingComboItems = Calculate(Count(Table[Combo_Item_Included]), Table[Combo_Item_Included] = "No")

But how do I make it count only 1 missing starting fee on #Invoice2?

Current result (Missing base fees):
ItemA = 2,  ItemB = 2

What I want:
ItemA = 1, ItemB = 2 

[ryan_mayu · Accepted solution]

@eaj 

pls try this

Measure = CALCULATE(DISTINCTCOUNT('Table'[#Invoice]),FILTER('Table','Table'[Base_fee_included]="No"))

[jgeddes]

You can try the following.

MissingComboItems =

var _vTable =

SELECTCOLUMNS(

    Table,

    "_row", CONCATENATE(Table[#Invoice],Table[Main_Item]),

    "_included", Table[Base_fee_included]

)

Return

COUNTX(

    FILTER(DISTINCT(_vTable),[_included] = "No"),

    [_included]

)