Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Enhance your career with this limited time 50% discount on Fabric and Power BI exams. Ends August 31st. Request your voucher.

Reply
Anonymous
Not applicable

Count and Distinctcount broken when Many to Many relationship Exist

I have a table containing Person ID and criminal registration. Sometimes one person can have two registrations. This table is then connected to a crime occurance table which details when a crime occurs and also holds the Person ID element. These end up being a many to many relationship. The relationship seems to make the function count and distinct count be incorrect.

 

When I do not link and perform the funcitons on the Registration table I get a count of 1,222,890 and a distinct count of 1,002,856. Once I turn on the relationship the number becomes about 500,000 and is identical for both counts. How can I fix this error?

2 REPLIES 2
Greg_Deckler
Community Champion
Community Champion

So many-to-many relationships are generally not a good data model. I would recommend by starting with creating a bridge table between the two tables in question.



Follow on LinkedIn
@ me in replies or I'll lose your thread!!!
Instead of a Kudo, please vote for this idea
Become an expert!: Enterprise DNA
External Tools: MSHGQM
YouTube Channel!: Microsoft Hates Greg
Latest book!:
DAX For Humans

DAX is easy, CALCULATE makes DAX hard...
Anonymous
Not applicable

I have created the bridge table and allowed filtering to go both ways, otherwise it still wasn't working the way I needed. So I guess that leaves me with two questions. I have three tables, all are now 1 to many and both connections have cross filtering enabled. Will this have a negative impact on my visuals? Secondly how do I know if my visuals are correct? I have about 8 million rows of data so verifying seems a bit difficult to me.

Helpful resources

Announcements
July 2025 community update carousel

Fabric Community Update - July 2025

Find out what's new and trending in the Fabric community.

July PBI25 Carousel

Power BI Monthly Update - July 2025

Check out the July 2025 Power BI update to learn about new features.