Forum Discussion
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
- Greg_Deckler
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.
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.
