Count if not linked

[Roym]

I have in my data model two tables. They have a linked relationship between the column 'control.

When I create a table in my report to show the issues were the 'control' is not linked this works. The value is column 'issue name' and the filter is 'count of control' isblank. This shows the table of the issues that don't have a control linked.

But now I need to make a card that shows how many issues there are that are not linked to a control. When I create the card, and add 'count issue name' as the  field with a filter on 'control is empty or isblank' they both show (blank) as value. I'm not sure in which directing I nee to think to get this working. Anyone any idea?

In the below example I would like to see '1' as there is one issue that is not linked to a control. 

Table1

Issue name	control
issue1	control1
issue2
issuex	control3

Table2

control	issue name
control1	issue1
control2
control3	issuex

[amitchandak · Accepted solution]

@Roym ,

Nor very clear. Two measures I can think off

countrows(filter(Table1, isblank(Table[control])))

or

Countrows(expcept(distinct(Table1[Control]), distinct(Table2[Control])))

[Roym]

Thanks! Got it working this way