Count number of instances of column values that don't have duplicates

[Vauban]

Hi to all.

I have searched for hours but possibly in the wrong place so apologies if this is out there.

I have a Task Activities table with a column of data (Folder_ID) where some but not all of the values are duplicates.

It's okay for there to be duplicates there but I just want to count the number of rows where the permit in that row doesn't have a duplicate elsewhere in that column.

Example:

Task ID      Permit No.           Note for being clear here

1                BP001                  Only 1 instance

2                BP002                  More than 1

3                BP003                  Only 1 instance

4                BP002                   More than 1

5                BP004                   Only 1 instance

6                BP005                   More than 1

7                BP005                   More than 1

What I would be expecting is Permit No.'s BP001, BP003 and BP004 to be found and the count value would be 3.

This was my latest attempt:  

First and Done = calculate(distinctcount('Task Activities'[FOLDER_ID]),filter('Task Activities',calculate(COUNTROWS('Task Activities','Task Activities'[FOLDER_ID] < 2))))

I would really like to not add another column to this table so if it can be done by a measure I would be glad.

Best to all,

David

[Vauban · Accepted solution]

Sorry to all.  I think I found the solution:  Solved: How to count the number of non-duplicate values in... - Microsoft Power BI Community.

I just tried it and tested it and it worked!  @Greg_Deckler, thank you for the solution on the link.

Wish I had found the recommended solutions before I pressed Send initially.  Oh well.   🙂