Table relationship (one-to-many) not working in visual

[cjacobson]

I have two tables:

Patients has unique idPatient

UPDRS has scores (multiple per patient) and is linked to Patients via idPatient

Here's my one-to-many relationship:

By everything I've read here and elsewhere this seems to be the right way to do it.

However, the simplest visual I could think of just shows the total number of patients for every option. I did a New Measure to count the number of patients.

Number Patients = DISTINCTCOUNT('Patients'[idPatient])

Then I created a table visual with intQ18 (possible answers of 0 through 4) and that Measure. Since it didn't work I also tried letting PowerBI do a distinct count.

As an example: idPatient 1625 scored a 1, 2, and 4 at different times and should be counted in those buckets and not the other ones.

Things I have tried:

• Making sure the relationship is active
• EDIT: Switching the direction of the relationship
• Switching intQ18 from Sum to Don't Summarize
• In modeling view, switching idPatient in both tables from Whole Number to Text
• Checking that the number of rows in the Patients table matches the number of rows in the actual patient table in the database (no duplicates)

Your help is much appreciated.

[parry2k · Accepted solution]

@cjacobson change your DAX like this

Number Patients = DISTINCTCOUNT(udpr[idPatient])

[cjacobson]

@parry2k Seems to have worked!

So the short version is "do your counting in the table that has 'many' IDs, not in the table that has 'one' ID". Is that correct? Is it only true for if the thing you are "grouping by" like my intQ18 is in the 'many' table?

Thank you!

[parry2k]

@cjacobson it depends what you are trying to do, if you have using column from many side then your calculation should be on many side column, in this case you are counting by column from many side which cannot filter patient table, although that can be achieved by cross filter direction set to both.

So there are many option, it all depends what you are trying to achieve and how you set up you data model.

[cjacobson]

@parry2k 

OK, wonderful. I will try to keep that in mind.