List on a chart table values that appear only once

[lailarhc]

Hello.
I have a chart table with a column where I list employees and another where I list courses they have taken.
Employees who have not taken any course are only listed once with an empty string for the course column value.

I want show on another chart table only the employees whose count are equal to one.
But I get an error when I try my solution.

Here's my table:

As you can see, there's only one employee who only appears once. That's the one employee who has not taken any courses. I want him to be the only one listed.

I've tried putting this on the Employee field: =if((Count(Employee) = 1), Employee)
But it says it's an Invalid Dimension.

What am I doing wrong? Is my logic flawed? Please help me.

Thank you in advance.

[GaryGiles · Accepted solution]

Try the following as your dimension definition for your second table:

Aggr(Only({$<Employee={"=Count([Course])=1"}>} Employee), Employee)

The set analysis {$<Employee={"=Count([Course])=1"} could also be used in a measure definition to limit what Employees are included.

Note: I did change the count object to [Course].

Hope that helps.

[lailarhc]

It worked! Thank you 🙂