Join paths are expected to form a tree

[jpsf]

Hi everyone,

I've been trying to solve this problem for a week but can't find a workable solution - a bit tired and desperate by now! I've read many forums here about the same problem and the microsoft learn docs on Model relationships, Star schema and Userelationship.

RLS is giving me the Join paths are expected to form a tree error in a visual. This happens in the report pages where I have the [Email] = userprincipalname() dax filter for the security group students (table alunos). in another report page with the same visual, in which only teachers have access and doesn't use the [Email] = userprincipalname() dax filter, all is well (I'm using page level security with RLS). I understand that the relationship hr_oa (Sigla de OA) <-> cd_oa_descritivo (sigla de OA) is generating the error, but I need it to build the visual as it is currently implemented. Can't use userelationship as I'm not using compatible dax functions. Do you have any ideas?

Regards,

[WishAskedSooner · Accepted solution]

Judging from the fact that you have 3 Many-to-Many Relationships as well as 2 bi-directional relationships, and have spent a week troubleshooting your errors, it is high time for you to invest in a copy of Microsoft's The Definite Guide to DAX. This will walk you through when and why to use them as well as additional techniques e.g. bridge tables. Very little can be communicated in a forum on how to fix your data model. Only you understand your data model and your requirements.

[jpsf]

Thanks, I've removed one bidirectional relationship. I'm reading about bridge tables here https://www.seerinteractive.com/insights/join-many-many-power-bi, that opened a possible way to go! I'll try to test it today.

gonna buy that book 😂

[jpsf]

With the bridge method I have it working now! the data model became a lot simpler... Thanks for pointing me in the right direction!

[lbendlin]

As the message says - you have ambiguity in your data model.  May want to clean that up. You also have two bidirectional joins - try to avoid these.