Countif with a column from a different dataset

[sinigagliafeder]

Hello everyone, 
can you please support me with the following dilemma?

I would like to have in a column the count of activities created by each user (not performed by each user, the difference is that supervisors monitors the activities but do not perform them). So what I did so far, is create a new table, get all distinct users of that specific app proceed to compute the amount of activities for each one of them. However, Im having difficulties in finding the right formula. 

As visible from Screnshot below the formula returns an error. As you can see from the formula I would like to count the activity performed for each email that should be eatual to the app user in another dataset. 

Any leads?

[PhilipTreacy · Accepted solution]

Hi @sinigagliafeder 

You should always provide some data when you ask people to write DAX against it.  

COUNTROWS takes a table as an argument, thats' what the error is telling you.

Try this but I'm not sure it's what you are after, I'll need to see your data and you should provide an example of the result you expect

= CALCULATE(COUNTROWS('Coaching Tracker'), FILTER('Coaching Tracker', RELATED('Count of Activities'[Email]) = 'Coaching Tracker'[App User]))

Regards

Phil